Home Travel Stories Gas Logs 1967 OLDSMOBILE Cutlass 330-2 bbl MPG= 8.7 City/ 18.5 Hwy
1967 OLDSMOBILE Cutlass 330-2 bbl MPG= 8.7 City/ 18.5 Hwy PDF Print E-mail
Written by Double Dragon
Saturday, 09 October 2010 10:24

1967 OLDSMOBILE Cutlass 330-2 bbl MPG= 8.7 City/ 18.5 Hwy


Writing and photography copyright D. S. Brown, AMA specs and Protect-O-Plate copyright Oldsmobile, GM, credit card slip copyright Gulf.


Metric= 5.4 L engine- 27 L/100 km City and 12.9 L/100km Hwy


In this article we profile a 1967 Cutlass owned by Magnus King. Look for the "DESERT OLDS", "ROUTE 666", and "HIGHWAY 61 MISSISSIPPI FLOOD" stories Magnus wrote about long journeys taken in this Cutlass in the DESTINATIONS part of the TRAVEL STORIES section.




The May 1967 POPULAR MECHANICS Owner's Report rates the average 1967 Cutlass at 13.1 City MPG and 16.6 Highway MPG. Drivers covered 919,922 miles with the 330 engine and Jetaway two speed automatic transmissions. Most owners drove the 320 HP four barrel high compression 330 which has the greatest MPG potential. High compression creates greater engine efficiency and the four barrel can squeeze out more MPG than the two barrel when driven on the small primary bores of the carburetor. Total cost of fuel increases somewhat due to the need for premium octane gas.

The four barrel stalls if you give it more than half throttle before it's fully warm. A letter to POPULAR MECHANICS Jan, 1970 complained about this. The rear barrels are kept closed by a thermostat. Flooring it when cold starves the engine for fuel and stalls it. Thus, the four barrel has a built- in 'moderator' subduing drivers from pushing a cold engine as hard as the two barrel carburetor allows.

The four barrel automatic MPG advantage fades slightly out on the highway. The four barrel is teamed with a 3.08:1 axle causing the engine to turn faster at highway speed than the two barrel engines which run through the 2.78:1 axle.

The OOCC Cutlass owned by Magnus King is a two barrel car with the 2.78:1 axle. The 250 hp 330 engine is shown below in a photo from the 1967 Oldsmobile brochure.


Magnus' Cutlass Town Sedan body style accounted for 22.5% of the respondents in the Owners Report in POPULAR MECHANICS. The other three similarly shaped body styles accounted for roughly the same percentages, with the less aerodynamic, heavier convertibles and wagons only counting for 9% of the answers. Most of the respondents outfitted their Cutlasses identically to Magnus with 330, automatic transmission, power steering, power brakes and radio.

41.5% of the respondents in the POPULAR MECHANICS article had Air Conditioning. Magnus' Cutlass is a typical Canadian car of the era without A/C. This saves the work of hauling the extra weight of the A/C unit as well as the power needed to run it.

In 1967 Mandy Williams Olds entered a 1967 Olds F-85 330 V8 into the Mobil Economy Run from Los Angeles, CA to Detroit, Michigan. The 2,837.8 mile trip was run from April 4-9, 1967 by Mandy Williams in person as driver. The Mandy Williams Olds unfortunately posted the lowest MPG figures for intermediate sized V8s with 17.06 MPG over the route. Other General Motors 'A bodies' did slightly better with a Chevelle Malibu from Bill McGuire Chevrolet (Buena Park, CA) posting 18.6 MPG; and a Buick Special from Colonial Buick Inc (Glendale, CA) posting 19.71 MPG. The winner of the class was a Plymouth Belvedere II from Hollywood Chrysler Plymouth with 20.0 MPG.

A 1967 Oldsmobile Cutlass Supreme was compared with a 1968 Oldsmobile Cutlass Supreme for the MOTOR TREND July, 1968 issue to highlight methods engineers used to improve both fuel mileage and performance simultaneously. Both were 2 doors with automatics with power steering, front disc brakes and A/C. The 1967 car had a 330- 4 barrel with 10.25:1 compression and a 3.08:1 axle. The 1968 had a 350- 4 barrel with same compression but a lower 2.78:1 axle (the same axle used on 2 barrel cars in 1967).

The simulated City Driving yielded 13.9 MPG in the 1967 Cutlass and 14.7 MPG in the 1968. It was noted that the figures would be lower in an L.A. type city (course mimicked Detroit which has many one way streets and fewer stops). Highway figures were 15.6 MPG for the 1967 and 17.4 MPG for the 1968. Steady speed MPG was 17.9 at 50 MPH in 1967 and 20.7 in 1968. 70 MPH in 1967 was 15.0 MPG and 16.9 MPG in 1968. A/C use chopped 1.5 to 2 MPG off the totals.

Check out the articles in the GAS LOGS under these titles: "1967 OLDSMOBILE Cutlass Supreme Turnpike Cruiser" and "1967 OLDSMOBILE 442" The 400 engines in the Turnpike Cruiser (revolutionary for its time) and the 442 (considered one of the best balanced muscle cars of the era) give surprisingly good MPG compared to the little 330 engine.



Magnus' 1967 Cutlass Town Sedan was built Tuesday Dec 20, 1966 at the GM factory in Oshawa, Ontario, Canada. Tuesday is traditionally a good day for quality assembly practices. The weekend hangovers have faded with less sick replacement workers learning by trial and error on the production line. The Cutlass was painted D code Nantucket Blue with a 923 code blue interior. It had the basic 330-2bbl single exhaust 250 HP, M33 two speed auto, open 2.78:1 axle and 7.75x14 tires.

Nine Options:
1) N40 Power steering
2) J50 Power brakes
3) B80 Roof drip molding
4) B85 Molding belt reveal
5) P01 Wheel trim cover
6) P62 4 Ply Whitewalls
7) U63 Pushbutton AM radio
8) A02 Tinted windshield
9) A39 Deluxe seatbelts

67 cutlass protecto 12 month page.jpg

The Cutlass was shipped Dec 21, 1966 to the Victory Motors Ltd. car dealership at 1675 Pandosy Street in Kelowna, BC, Canada. Victory Motors is now named Don Folk Chevrolet. A brief history appears in the BC/ KELOWNA story in the DEALERSHIPS section of this website. Protect-O-Plate records infer that the Cutlass was sold late February, 1967.

67 cutlass protecto 18 months

The Protect-O-Plate and gas receipts place the Cutlass in Penticton, BC during the 1960s and 1970s. The July 29, 1968 Protect-O-Plate stamp above indicates that the Cutlass was serviced at a secondary dealership location for Victory Motors located in Penticton. The second Victory Motors location owned by Don Folk was named Folk's Auto Sales & Service at 2020 Main Street, Penticton, BC.


Provincial records indicate that the first owner didn't sell the car until 1980. However, the 30 month Protect-O-Plate validation and later ones are unused. The owner's motive for ceasing warranty maintenance may be related to the low mileage on the car in later years. The first owner seems to have passed through the latter portion of the warranty period without driving much.

67 cutlass protecto 30 months

In 1980 the Cutlass was sold in Osoyoos, BC with 70,000 miles. Osoyoos is a desert area in the BC interior which preserved the car from major rust. Four years later at 84,000 miles the Cutlass was sold to a woman in Osoyoos. In six years she logged 45,000 miles on the car, the most miles per year the car had been subjected to thus far. Her neighbor, a truck driver bought the car at 129,000 miles. He used the car to move his belongings to New Westminster, BC.

A few months later the trucker sold the Cutlass to Magnus King at 132,000 miles making him the fifth owner.



Magnus King's Cutlass has typical options found on the majority of brand new Cutlasses back in 1967.

Magnus' 1967 Oldsmobile Cutlass 4 door Town Sedan is original except for the modern tires, shocks and battery. The carburetor was rebuilt. The Cutlass has original configuration replacement exhaust, brake pads, tires and radiator. The Cutlass has original interior, glass, drive train, alternator, master cylinder, water pump, steering box, springs, brake drums and exhaust manifolds. Magnus' Cutlass retains the original steel wheels and hubcaps. It has four wheel drum brakes which create less drag than the front disc option.

Incredibly the Cutlass made it through all this time without ever having an accident or even a minor insurance claim for glass. This is the advantage of owning cars out in the country: less populous areas rarely experience fender benders and vandalism. The car has a minor dent in the top front bumper but the frame seems to be unaffected. Cars with perfect alignment get better MPG and this one tracks true.

Magnus's 195R70-14 Michelin tires are shorter than the stock 7.75 x 14 bias ply tires which are equivalent in diameter and width to P 215R70-14 tires. Magnus' tires were produced in the mid 1980s. They are only 70% as tall as wide: 'low profile' by 1960s standards. See the article about tires in this GAS LOGS section for more information.


Tire diameter of the radials works out to 24.7" (696 mm). This tire revolves 840 times per mile while the original Cutlass tires only revolve 780 times a mile. The Cutlass has to turn the wheel an extra 60 times per mile when shod with a radial of the same width as the old bias ply. Theoretically this will force the engine to rev about 8 % faster than with the stock tires costing the Cutlass 8% MPG and also some engine longevity.

This is compensated somewhat by the fact that radials improve gas mileage by about 3 to 8 % (depending on what source you consult) over bias ply tires. Whatever the exact amount, those 1967 tires didn't have modern compounds to further lower rolling resistance so the new tires probably equal or improve the situation.

To confuse this issue, the rear radial tires on the Cutlass were snow tires with the squared off taller tread joined to the leading edge of the tire. The extra deep snow tire treads might have increased the sidewall height and hence tire diameter. Of course, snow tires have far more rolling resistance due to the aggressive tread pattern and softer rubber used, which may knock MPG right back to square one.

Magnus states that Interstate mile markers indicated "the odometer was reasonably accurate." Magnus' off the cuff observation assures us that the odometer wasn't grossly out of whack, which was a common problem on 1960s cars. Later when Magnus switched to 225R70x14 tires, the odometer didn't vary noticeably, so the differences these tire switches caused in the real world were probably not significant.

The Cutlass original 1967 factory issue bias ply tires had a suggested inflation of 24 PSI, while modern radials are safe at 35 PSI, which further reduces rolling resistance and improves MPG a few more points over the original showroom stock cars. In the end, the smaller diameter radial tire MPG loss was probably regained by the radial configuration and high air pressures.

Below are some pages out of the AMA specs provided by Oldsmobile about the 1967 Cutlass. To see other pages of this booklet, see the story on the 1967 Turnpike Cruiser in the GAS LOGS section. AMA sheets are available through the Oldsmobile History Center, Lansing Michigan and also GM Canada Historical, Oshawa, Ontario.

Olds selected the model numbers below to give an overview of the lineup compared across the four door body style. 33369 is the F85 base six cylinder four door sedan, 33469 is the F85 base V-8 330 two barrel four door sedan and 33869 is the Cutlass Supreme high compression 330 four barrel four door.


Magnus' Cutlass weighs in on the lower end of the scale where it recorded poor City MPG, but paradoxically, Magnus' car was loaded down for Highway trips and still exceeded average highway MPG despite hauling excessive weight.

67 oldsmobile cutlass ama specs weights

According to the AMA sheet above, the basic V8 330 Cutlass Town Sedan weighs 3,387 lbs, fairly light for such a large car. 1960s cars didn't weigh much despite extravagant non functional heavy steel design cues in the all metal bodies. Weight is held down with an absence of airbags, 5 mph bumpers, and safety steel beams in the doors, roll over standard reinforced roofs, catalytic converters, GPS, stability control computers, engine management computers, quadraphonic stereos etc.

The automatic transmission adds 11 pounds over the manual transmission, power steering adds 35 pounds, power brakes add 10 pounds, and the radio weighs 8 pounds. Magnus' Cutlass with options weighs 3,451 pounds with fluids topped up. In metric that is 1,565 kg.

The modern battery weighs about 35 to 40 pounds, in the same general range as the original 1967 Delco. Technically, Magnus' Cutlass had a few more pounds because radial tires weigh more than Bias Ply. The 195 sized radials on the Cutlass weigh 21 pounds each, while the 225s mounted to the car later are around 25 pounds each. The unsprung weight of tires creates more work than the few extra pounds would as dead weight in the trunk. Unsprung weight gets complex because the larger diameter tire created with the 225s bring rotational inertia into the picture. We'll leave that formula for the diehard experts.

When we add Magnus' driver weight we end up with a 3,550 pound car with oil, coolant, no passengers and partially full gas tank. In City driving Magnus's weight is offset somewhat by frequently running on a quarter tank or gas or even less. As he says, "right down to the fumes sometimes." With a 20 gallon gas tank constant quarter tank status removes approximately 15 gallons (90 pounds) off the cars curb weight. The top 3/4 on the gas gauge covers more gasoline than the other quarter marks on the gauge like most GM 1960s cars, so it might be more like 16 gallons (100 pounds) weight savings.



Magnus' atrocious city MPG may be attributed to the ethanol content in modern gasoline and the cold weather in Vancouver, British Columbia, Canada. Magazine tests were made back in the day when these cars were new and gasoline wasn't watered down with efficiency robbing ethanol.

Magazines typically tested cars in warm USA locales which boosts MPG. The readers reporting MPG in Popular Mechanics Owners Reports lived in the USA. California has a huge population. The sheer volume of warm weather condition drivers reporting might have skewed the figures enough to improve the overall average.

Back in the 1960s a drive across town averaged 35 mph without the perpetual gridlock of modern cities. To this day, Vancouver lacks a highway through town. Every inch of travel is an endless series of ill timed traffic lights and enforced waiting at intersections generally devoid of advance left turn signals.

The 8.7 CITY MPG figure is averaged from 1,000 miles of aggressively driven short trip winter stop and go that yielded 8.9 MPG and 1,000 miles of faster driving in spring that registered 8.5 MPG. The carburetor was rebuilt and engine received a complete tune-up at 133,285 miles. There are 2,000 undocumented winter miles from this period due to Magnus not keeping a regular gas log, but the fragments recorded are in sequence, so the figures are accurate.

Several other sporadic logs were made over the years. Magnus kept track for a few fills to ensure the car was still in tune and then dropped the practice again for months. Thousands of miles of city driving are not documented at all.

The trips were usually made carrying just Magnus' driver weight. The Cutlass was always parked outside. Vancouver winter average temperature hovers at 2 degrees C (36 F) but Magnus states that year had exceptional snow and cold. The car was driven about 3 miles or less for each trip which isn't sufficient to achieve operating temperatures where MPG begins to optimize.

Oil changes using Quaker State or Esso brand 10W30 oil were done every 3 months. Oil top ups used Quaker State or Motomaster 10W30. Motomaster is the Canadian Tire franchise oil brand name. A tech person working at Canadian Tire stated that the oil in the bottles is a National oil brand packaged under the Motomaster name.

Gas used was 87 Octane unleaded with an occasional infusion of leaded gas. Magnus used reputable National brands but didn't have any favorites. A Shell station near his house was frequently used due to its proximity. Modern unleaded gasoline has up to 10% ethanol content so there was a significant portion of the gasoline used which had lower total energy potential than the gasoline used in the 1960s. Ethanol reduces MPG. The leaded gasoline Magnus used was likely not diluted with ethanol.

During this period of winter driving, the wipers, fan, and radio were usually on. Snow tire Radials at 35 PSI. The stock Cutlass was approaching 25 years old, with 132,000 miles on the original 330 engine. The Michelin radial tires on the car had only 20,000 miles of use, but the DOT date of manufacture was mid 1980s. The old rubber lacks the lowered rolling resistance formulas developed in the late 1990s.

Here is the raw data from Magnus' gas log.

First column lists odometer mileage, second column is the number of gallons. Third column specifies octane. Unleaded gas is the default unless leaded gas is listed. An 'X' in the fourth column indicates that the tank wasn't filled up, a regular occurrence due to Magnus' constant state of poverty. Column five lists the MPG when it was possible to calculate.

Odometer  Gallons   Octane/ Lead?  Full Tank?   MPG (uncorrected)

32,525         4.5                                X 
32,540         4.5                                X 
32,593        18.5     87 oct leaded     Full tank 
32,737         9.1                                X 
32,770         3.1                                X 
32,837        15.0     87 oct leaded     Full tank     8.9 MPG
32,968         2.6                                X 
33,010         5.2                                X 
33,056         5.2                                X 
33,095         2.6                                X 
33,118         5.2                                X 
33,154         5.2                                X 
33,197       10.4                                X 
33,282        5.2                                 X 
33,339        5.2                                 X 

33,388        5.2                                 X 
33,422        4.7                                 X 
33,450        2.3                                 X 
33,460        5.5                                 X 
33,494        9.5                                 X 
33,562        5.2      87 octane            X  
33,597        5.5                                 X 
33,646        6.8                                 X 
33,693        2.2                                 X 
33,705        6.4                                 X 
33,769        5.3                                 X 
33,800       15.0                                X

Cold weather forces the choke to stay on longer, and winter gasoline formulas produce lower MPG. Cold engine oil creates more resistance inside the engine while wet roads offer tires more rolling resistance. Even the cold air's increased density creates more air drag on the car.

Taking all of this into account we would assume that the warm weather (13 to 15 degrees C which is 55 to 66 F) in spring should improve mileage, but the Cutlass springtime MPG drops to 8.5 MPG. Now that the roads were dry, the Cutlass was being driven faster and harder which may account for the lower MPG.

Odometer  Gallons   Octane/ Lead?  Full Tank?   MPG (uncorrected)

35,871           5.0                                X 
35,929           3.0                                X 
35,996           1.7                                X 
36,009         10.1                                X 
36,139           2.2                                X 
36,164           2.2                                X 
36,189           2.2                                X 
36,300           4.3                                X 
36,353          17.0     Leaded 87         Full tank    8.5 MPG

A later excerpt of winter gas logs reveals improved City Mileage. These figures include about 60 miles of highway cruising. That leaves 475 miles actual city driving. Assuming that the car registered 18 HWY MPG as usual, deducting 3.3 gallons from the total leaves 38.4 gallons to drive 475 miles which translates to 12.3 MPG. The improved city mileage is possibly explained by a complete tune up done at 50,495.

Odometer  Gallons   Octane/ Lead?  Full Tank?   MPG (uncorrected)

50,310         17.7         Leaded 87     Full tank
50,526          2.2                                X 
50,545          4.8                                X 
50,600          6.6                                X 
50,700         12.0                               X 
50,700          6.6                                X 
50,845          9.5                                Full tank 12.8 MPG

Note that the Cutlass didn't manage to match the MPG posted by a 1967 Pontiac Beaumont and a 1967 Pontiac GTO also profiled in the GAS LOGS. Both Beaumont and GTO are General Motors 'cousins' to the Cutlass which share similar configuration chassis, suspension and body shape.

The GTO managed 11.7 MPG over 10,000 miles of driving. The owner Bill Nawrot used the GTO for his work commute and 'cruising'. The GTO was 200 pounds heavier than the Cutlass and sported a much larger 400 engine with 4 barrel carburetor.

Part of the explanation for the GTO efficiency derives from the colder weather the Cutlass had to slog through. The MPG figures for the Cutlass were recorded in the 1990s when traffic congestion was worse. Illinois streets in the 1960s had longer stretches between traffic lights and less gridlock. Bill also logged many hours out cruising his GTO pretty late at night with light traffic for most of the miles.

The Cutlass did have advantages denied to the GTO. The Cutlass radial tires inflated to 35 PSI gives a big advantage over Bill's GTO pushing through squirmy energy robbing bias tires set at a soft 24 PSI which sucks up MPG. The Cutlass also enjoyed easier turning via lower friction modern engine oils.

That high compression GTO engine drinking leaded premium is just more efficient than a 9.5:1 Ods or Chevy motor using unleaded gas. Also the parasitic loses of automatic transmissions that were hampered by a mere 2 forward speeds lose out to Bill's non slip 3 speed manual that keeps the engine in a more efficient range.

The 1967 Pontiac Beaumont also chronicled in these GAS LOGS managed 11.5 MPG city. The Beaumont had radial tires and was driven in the same cold conditions and in modern traffic like the Cutlass. The lighter smaller Beaumont ran a 283 2 barrel which is smaller than the Cutlass engine. The Cutlass had a more efficient 'switch pitch' Jetaway automatic transmission versus the simpler Chevrolet Powerglide used in the Beaumont. So with modern tires, oils and driving conditions and similar weather how come the Cutlass still lost?

Both GTO and Beaumont had steeper rear gears than the Cutlass and this may account for the poor city showing for the Cutlass. The 3.08:1 gears in the Beaumont and the 3.23:1 gears in the GTO give better stop and start performance than the 2.73:1 highway gears in the Cutlass.


HIGHWAY MILEAGE 1967 CUTLASS = 18.5  MPG (41,000 miles minus 7,000 miles missing records equals 34,223 miles of logs)

Road trips that netted 18,2, 18.6, 18.8 average out to 18.5 MPG overall.



Magnus had the advantage over new Cutlasses back in the day on the highway driving portions. Magnus had a well broken in engine combined with a highway axle. Most Cutlasses tested in magazines ran a typical 3.08 axle, not Magnus' lower 2.78. Modern tech gives us superior oils and tires allowing cars to extract more MPG than owners and road testers from back in 1967. Magnus logged HWY miles in weather comparable to the warm areas used in magazine tests. Only a small proportion of his highway miles occurred in low temperatures.

The advantage in the early magazine tests is that in the 1960s pure leaded gasoline was available with more energy per gallon. Our modern gasoline is cleaner burning which is better for avoiding engine deposits, but the actual energy available in ethanol diluted gas is lower than the old gas.

The 18.2 HWY MPG figure was achieved over 14,000 miles of cruising at 70 mph (112 KPH) on Western and Southern Interstates in spring, summer and fall. There are some sustained periods of 90-100 mph cruising. The only time there was a very significant drop in Interstate MPG occurred during a long 110 mph run netting less than 12 MPG.

Mileage was also racked up on secondary highways taken to dodge toll roads. The city driving entries mixed in here occurred late at night on deserted roads, which won't affect MPG the way daytime stop and go does. With such a huge total these deviations from 70 MPH Interstate cruising are absorbed into the average.

There are occasional fluke high readings like 27 MPG, likely related to premature fuel shutoff on the gas pump giving a false 'full tank' condition which skews calculations. Gassing up at different places changes the angle of the pad the car is parked on, creating a different 'full shut off point'. The car was sometimes loaded to the point that the rear end was almost dragging. At other times all the stuff was stashed leaving the car sitting high, which changes car angle and the gas tank position.

The Cutlass was always parked outside with temperatures ranging from 70 to 115 degrees F (21 to 46 degrees C). Magnus' involuntary road trip diet shed 10 pounds, dropping driver weight to 175 Lbs (80 kg). For most of the trip there was also a 175 Lbs (80 kg) passenger and about 500 pounds (225 kg) luggage. At the start of the trip there were 3 passengers and much more luggage. At the end of the trip the 175 pound passenger and luggage was replaced with a 100 Pound passenger and minimal luggage. Later still, the load comprised just Magnus, no passenger and a virtually empty car, as luggage and tools were sold off to finance the gasoline.

The lack of Air Conditioning saves extra work for the engine with absent A/C unit weight and parasitic power drain. This advantage was negated by constantly driving with all windows rolled down. Open windows create a parachute effect as the engine strains to pull against the resistance of the rear window. The vent windows were always fully open, creating an obstruction which lowers the co efficient of drag. The radio was always on requiring some extra engine energy, while the antenna was fully extended which might add a smidgen of drag. Frequent night driving meant the lights were on for much of the trip: another power drain. Half way through the trip, the antenna was broken off. The hubcaps flew off from hard driving, shedding some more weight.

Sixteen entries in the log indicate leaded gas, which was usually 87 octane. Whenever possible leaded gas was used and sometimes this is indicated in the gas log, sometimes not. There are about sixty entries that are possibly unleaded gas, but likely some of those were leaded gas that simply weren't noted as such. Only one entry specifies 92 octane gas, meaning that all other entries were likely 87 octane.

Unfortunately for this article, Magnus can't recall any of the stations used, other than one Shell station near a place he stayed in Oakland, California. A New Orleans, Louisiana station near a place he lived at for awhile may have coincidentally also been a Shell Station, but he said it may have been a Sunoco which also uses a yellow logo.

"When we pulled off the road to gas up, we used whatever was there."

He did fill up almost exclusively with National chain brands. Oil changes used 10W40 and 20W50 oil using the house brand of the garages doing the change which isn't indicated in the garage bills. Top ups used Motomaster and Quaker State 10W40.

The 195R70-14 radial snow tires incredibly survived sustained driving in desert heat at high speeds with heavy loads. Magnus couldn't justify spending the $30.00 to mount and balance the summer tires which were in the trunk for emergencies. Magnus ran the snows set at 35 PSI until forced to switch after he blew out both rear snow tires at 110 mph within a few miles of one another. The last 4,000 miles of the road trip used regular 195 radial tires.

Odometer   Gallons   Octane/ Lead?   Full Tank?   MPG (uncorrected)

36,353          17.0        Leaded 87        Full tank
36,581          15.0        Leaded 87        Full tank    15.2 MPG
36,867          13.0        Leaded 87        Full tank    22.0 MPG
37,167          15.0        Leaded 87        Full tank    20.0 MPG
37,500          13.5       Unleaded 87      X 
37,660           3.5                                X 
37,700           7.0                                X 
37,805           7.0                                X 
37,918           7.0                                X 
38,044          14.0                               X 
38,335           1.4                                X 
38,355           1.7                                X 
38,400          10.7                               X 
38,488          12.2                               Full tank  16.9 MPG
38,765          12.5                               Full tank   22.1 MPG
38,000          15.2                               Full tank
39,137           7.7                                Full tank   16.2 MPG
39,437         16.6                                Full tank   18.0 MPG
39,685         14.1                                Full tank   17.5 MPG
39,997         11.5                                X 
40,038         11.4                                Full tank   19.6 MPG
40,301           5.6                                X 
40,385           8.3                                X 
40,437         12.2        92 octane          Full tank   15.2 MPG
40,719         15.0         Leaded             Full tank    18.8 MPG
41,000          4.4         Leaded             X 
41,000          2.1         Leaded             X 
41,150         4.4          Leaded             X 
41,204        17.0          Leaded             Full tank  17.3 MPG
41,476         8.9          Leaded             X 
41,700       14.5          Leaded             Full tank  21.1 MPG
41,940       16.2          Leaded             Full tank  14.8 MPG
42,272       13.5           87 octane        Full tank   27.5 MPG
42,500         7.3          Leaded            X 
42,620         8.0                                 X 
42,678         8.0          Leaded            X 
42,947       14.8                                Full tank   17.7 MPG
43,236        12.0                               Full tank    24.0 MPG
43,454         8.5                                X 
43,635        5.3                                 X 
43,902       15.0                                X 
43,900        9.2                                 X 
43,900        3.0                                 X 
44,355      12.1                                  Full tank  21.0 MPG
44,653      15.3                                  X 
44,850        3.8                                  X 
44,997        3.8                                  X 
45,095        3.8                                  X 
45,118      15.5                                  X 
45,389      16.0                                  Full tank  18.1 MPG
45,690       6.1                                   X 
45,758       6.1                                   X 
45,900       3.8                                   X 
45,976      19.0                                  Full tank  16.7 MPG
46,250       7.6                                   X 
46,418       7.6                                   X 
46,563      12.0                                  Full tank  21.5 MPG
46,733       7.4                                   X 
46,959      12.0                                  Full tank  20.4 MPG
47,200      13.0                                  Full tank  18.5 MPG
47,335       8.5                                   Full tank  15.8 MPG
47,480      12.0                                  Full tank   12.0 MPG
47,698       7.0                                    X 
47,950       3.5                                    X 
48,031      11.0                                   Full tank  25.6 MPG
48,300       3.5                                   X 
48,375      11.8                                   Full tank  22.4 MPG
48,700       3.5                                    X 
48,756     10.5                                    X 
49,050     10.5               87 octane      X 
49,177     10.6               87 octane      Full tank   22.8 MPG
49,444     15.2               Leaded          Full tank   17.5 MPG
49,772     15.2                                    Full tank   21.5 MPG
50,100     15.2              Leaded          Full tank  
50,000       2.7                                    Full tank   18.3 MPG


ROAD TRIP NUMBER TWO = 17.1- 18.6 MPG HIGHWAY (6,000 miles)

This road trip produced either 17.1 or 18.6 MPG. The uncertainty of the mileage is due to an apparently missing fill up receipt. If it was missing, the figure is lower, if it wasn't, it is higher.

This road trip was done in winter and spring on approximately half Interstate and half secondary highways. Sustained speeds were possible on most of the secondary highways, but the road surfaces were rough and patchy which cuts MPG. Mountainous secondary highways were twisty and slow creating long periods at 20 or less MPH. Elevations up to 7,000 feet alter fuel air/ ratios, affecting MPG.

There is a segment of the trip where the car was running rough, and MPG hovered around 17-19 MPG. The mileage jumps to 21 MPG after a garage troubleshot the fairly new points that were too tight, causing engine 'missing'.

The Cutlass was pulling more weight this time. Magnus was 195 lbs. There were two passengers weighing 115 lbs and 145 pounds. The luggage was at least 500 pounds. Average cruise speed on secondary roads was usually 65 MPH while interstates averaged the familiar 70. There were long stretches of steady 90 MPH cruising whenever isolated roads were good quality.

The car often had the heater and defroster fan on, radio on, wipers on. The windows were usually rolled up. The temperatures were consistently below 0 C (32 degrees F) at the start of the trip and gradually made it up to highs of 60 F in the desert areas during daytime. The Cutlass was always parked out in the elements, actually getting buried in snow drifts overnight up in the mountains a few times.

At the very start of the road trip the Cutlass was running P195R70x 14 summer radial tires at 35 PSI. About 2,000 miles into the trip the tires were switched to P225R70x 14 Mud and Snow all season tires, also set to 35 PSI. These tires had a larger diameter which could cause the odometer/ speed to read lower than it really was. 1960s cars had a built in exaggeration factor in most speedometers, so the bigger tires probably closed the gap between reality and indicated speed.

Gas and oil was unchanged from the patterns established on the prior road trip. No attempt was made to distinguish leaded from unleaded in the gas log. Magnus was apparently wearying of details.

Odometer  Gallons           Full Tank?   MPG (uncorrected)

50,845         9.5               Full tank   
51,214         5.6                x  
51,292        18.4              Full tank    18.6 MPG
51,480         Missing entry ?  
51,663         11.3             Full tank         ? 
51,745           8.0             Full tank     10.2 MPG
51,966         13.7             Full tank    16.1 MPG
52,191         12.5             Full tank    18.0 MPG
52,406          8.3             Full tank     25.9 MPG
52,526          8.2             Full tank     14.6 MPG
52,796         16.2            Full tank      16.6 MPG
53,060         10.7            Full tank     24.6 MPG
53,309         14.6            Full tank     17.0 MPG
53,538         12.2            Full tank     18.7 MPG
53,732         10.4            Full tank     18.6 MPG
53,972         13.0            Full tank      18.4 MPG
54,260         13.0            Full tank      22.1 MPG
54,490         12.0            Full tank      19.1 MPG
54,700         12.0            Full tank      17.5 MPG
54,933         12.3            Full tank      18.9 MPG
55,058          6.6             Full tank      18.9 MPG
55,182          6.3             Full tank     19.5 MPG
55,471         16.0            Full tank     18.0 MPG 
55,706         11.0            Full tank     21.3 MPG
55,876          8.0             Full tank      21.2 MPG
56,014          6.4             Full tank     21.5 MPG


ROAD TRIP NUMBER THREE = 18.8 MPG HWY (14,000 miles)

The first 600-800 miles of this road trip weren't recorded, but the surviving receipts are complete and chronological. Existing records work out to 18.8 MPG HWY.

This road trip was taken in the Summer and Fall with temperatures varying from mild to miserable. Windows up, very wet roads and cold, damp air. Average speed was mostly 65- 70 MPH with relentless rain requiring continuous use of heater, defrost, fan, lights and windshield wipers. The trip was divided between Interstates and secondary highways, many of which were quite rough with high crowns, and patchy surfaces. But at all times the roads allowed continuous cruising.

The Cutlass moved a lot of weight for the first 6,000 miles; driver Magnus was 200 Lbs, passengers at 180 and 115, plus 500 pounds luggage and 100 pounds of canned food and drinks for total cargo weight of 1,100 pounds. Tires were 225R70x 14 M+S radials at 35 PSI. Oil was 10W30, with changes using unspecified house brand oil of local garages. Top ups used Quaker State 10W30.

The middle 4,000 miles of this road trip were made without the 180 pound passenger with luggage weight dropped to 350 pounds and most of the food gone. Total passenger and cargo weight was around 700 pounds. The weather was warmer and drier. Cruising briefly adhered to the traditional 70 MPH, but quickly jumped to long stretches of 90-100 MPH.

The final 4,000 miles of the trip had the same driver and passenger, but added massive amounts of cargo filling the trunk and rear seat. Original luggage was supplemented with six milk crates full of LP records, as well as over one dozen boxes of books. Cruising speed was a steady 70 through quite cold, but dry areas in the Midwest.

Surviving receipts from this road trip show that Magnus had good reason when he says that he couldn't remember the gas station brands he used on trips.

Here is a partial list of stations used on this trip: Amaco, Arco AM/PM, Big Country Oil, Blair's Truck Stop, Chevron, Citgo, Coffee Cup Fuel Stop, Common Cents Food Store gas, Conoco, Gasamat, Husky, Mobil, Philips 66, Pik Kwik, Quick Trips, Rebel, Road Hummer, Shell, Sinclair, Superamerica, and Texaco. There were more, but not all original receipts survived. Magnus recalled only using National Brands, but some of these stations seem unique to certain rural areas.

91 and 92 octane was used a few times, but the default 87 octane appears most often. Only one reference to leaded gas means the other sixty gas stops are presumed to be unleaded. Receipts often don't specify more than the amount and cost per gallon, so there may be more leaded gas use mixed into this list.

Odometer  Gallons   Octane/ Lead?  Full Tank?   MPG (uncorrected)

56,817          15.4       92        Full tank  
57,115          13.7                   Full tank   21.7 MPG
57,310          10.5                   Full tank   18.5 MPG
57,584          16.6                   Full tank   16.5 MPG
57,904            5.2                   X 
58,052           16.0                   Full tank   22.0 MPG
58,154            5.5                   Full tank   18.5 MPG
58,348            9.0     Leaded   Full tank   21.5 MPG
58,610           12.0                   Full tank   21.8 MPG
58,835            3.8                   X 
58,897           13.5                  Full tank   16.5 MPG
59,175           15.0        92       Full tank   18.5 MPG
59,437           13.0                   Full tank   20.1 MPG
59,681           11.0                   Full tank   22.1 MPG
59,953           12.8                   Full tank   21.2 MPG
60,107             8.0                   Full tank   19.2 MPG
60,346             5.0                   X 
60,500           11.0                   Full tank  
60,562             8.0                   Full tank   20.6 MPG
60,500           13.5                   Full tank  
60,500           10.0                   Full tank  
61,132            7.0        91        Full tank   18.6 MPG
61,340           11.0                   Full tank   18.9 MPG
61,594           14.3                  Full tank   17.7 MPG
61,801           13.1                  Full tank   15.8 MPG
62,049           11.7                  Full tank   21.1 MPG
62,230            2.4                   X 
62,253          14.3                   Full tank   12.2 MPG
62,491          11.9                   Full tank   20.0 MPG
62,721           9.7                    Full tank   23.7 MPG
62,958          12.6                   Full tank   18.8 MPG
63,102           6.9                    Full tank   20.8 MPG
63,394           7.0                    X 
63,561           3.5                   X 
63,582         13.2                   Full tank   20.2 MPG
63,875         14.7                   Full tank   19.9 MPG
64,168         13.9                   Full tank   21.0 MPG
64,405         12.3                   Full tank   19.2 MPG
64,693         13.8                   Full tank   20.8 MPG
64,955         13.3                   Full tank   19.6 MPG
65,263         16.4                   Full tank   18.7 MPG
65,545           3.5                   X 
65,622         14.9                   Full tank   19.5 MPG
65,893         11.5                   Full tank   23.5 MPG
66,004          6.6                    Full tank   16.8 MPG
66,300          5.2                    X 
66,334          5.2                    X 
66,382         17.4                   Full tank   13.5 MPG
66,666         17.2                    Full tank  16.5 MPG
66,869           7.6                    Full tank  26.7 MPG
67,117         15.9                    Full tank  15.5 MPG
67,314           8.4                    Full tank  23.4 MPG
67,000          13.9                   Full tank 
67,831          14.9                   Full tank  17.9 MPG
68,112          14.9                   Full tank  18.8 MPG
68,330          13.2                   Full tank  16.5 MPG
68,553          15.0                   Full tank  14.8 MPG
68,801          12.2                   Full tank  20.3 MPG
69,065          14.5                   Full tank  18.2 MPG
69,388          14.0                   Full tank  23.0 MPG
69,622          10.0                   Full tank  23.4 MPG



Magnus found record keeping on road trips impeded spontaneity. He stopped keeping gas logs but fragments of paperwork establish that the next road trip was approximately 7,000 miles long. Magnus was 205 pounds now. There was a 115 pound passenger, 500 pounds luggage plus 100 pounds of food and drink. The cruising speed stuck pretty much with the standard 70 MPH. The temperatures were 70 to 100 degrees F and the windows were down most of the trip.

Most of the conditions mimicked the previous road trips. Magnus recalls that the Cutlass seemed to be getting "about the same MPG as previous trips" despite a lighter load. He knew roughly how much distance equated with each quarter tank marking on the gas gauge from experience.

There were later road trips in the Cutlass that have no direct documentation. Several thousand miles of driving is lost to the mists of time. Magnus' memory is that there was nothing different about the car's MPG on the later trips or the general circumstances of the weight or driving conditions. The Cutlass engine ran just as smooth and strong as ever. The 225 tires bought in the 1990s are still on the car, so we don't know how much better the MPG might get if the new low rolling resistance compound tires were mounted on the car. Since the oil is changed every 3 or 4 months, the car always has the latest up to date energy efficient oil formulations.

The overall mileage covered in logs is 37,097 miles, minus 2,874 miles of gaps which provides 34,223 miles of records. 1,965.2 gallons were needed to cover this distance, which translates to 17.4 MPG overall for all driving. This figure is skewed by the sheer volume of Hwy driving records used relative to city driving records, so it's not included in the comparative figures listed for other OOCC cars.
























































Oshawa noon=

SU 28 SG/ MO 7 AR/ ME 12 SG/ VE 8 CP/ MA 8 LI/SA 23 AR/ UR 24 VI/ NE 23 SC/ PL 20 VI/ NN 15 TA

SU biq JU/ SU sq UR/ VE sq MA/ VE 45 NE/ MA 45 NE/ SA tr NE

Last Updated ( Wednesday, 06 November 2019 19:16 )