Home Travel Stories Gas Logs 2003 FORD Mustang 232 EFI Auto MPG= 22.9 Hwy
2003 FORD Mustang 232 EFI Auto MPG= 22.9 Hwy PDF Print E-mail
Written by Double Dragon
Tuesday, 28 December 2010 20:32

2003 FORD Mustang 232 EFI Auto MPG= 22.9 Hwy

Writing and photography copyright D. S. Brown


Metric= 3.8 L engine= 10.2 L/100 km Hwy


EPA Mileage figures when car was released 19 MPG City/ 27 MPG Hwy

The EPA wrung 19 City MPG, 27 Hwy MPG and an overall average of 22 MPG (12 L/100 km, 9 L/ 100, 11 L.100) out of a 2003 V6 automatic Mustang. The new EPA measuring system translates to 17 City, 25 Hwy and 20 overall. Seven actual real world drivers managed to get 16 City MPG and 27 Hwy MPG when their figures were averaged out on the EPA site.

03 mustang roadtrip

The photo above shows the OOCC Mustang parked in an Eaglehorn, North Carolina abandoned service station. The car is a totally stock 2003 Mustang with 4,000 miles on it. Break-in was complete at 1,000 miles. This car is bone stock with no deviations from factory issue equipment, right down to the factory installed oil and filter.

The door tag informs us that the OOCC Mustang is Zinc Yellow (code B7). It was manufactured in January, 2003 in the Dearborn, Michigan final assembly plant (code F). It has the six cylinder engine (code 4), four speed overdrive automatic (code U) and the conventional 3.27:1 axle (code Z5). The door sticker states that the 225/SSR16 radials should be inflated to 35 PSI front and rear and maximum load is 700 pounds. The engine sticker tells us the engine was built Jan 16, 2003 in the Windsor, Ontario engine plant.

The base aluminum V6 cylinder 3.8 L engine displaces 232 cubic inches. This V6 single exhaust engine has more displacement than the old six cylinders of earlier times. A base 1965 Mustang came with a 170 cubic inch 8.7:1 compression inline six cylinder capable of 101 brake HP. As the Mustang grew, so did the base and optional inline 6 cylinder engines. The Mustang base engine jumped to 200 c.i. during the 'classic years' with a 250 optional. Forums state that the inline 6 cylinder 200 c.i. with automatic and typical 2.90:1 axle managed 24 MPG highway. The modern 232 is a far cry from the old carbureted straight six pushrod single exhaust engines of the 1960s.

Fuel injection, computers and overhead valves do their job in making the 2003 V6 Mustang capable of much quicker acceleration and sustained high cruising speeds when compared to the original six cylinder Mustangs. The 2003 can hit 60 MPH in 9.9 seconds and is rev limited to 115 MPH while the 1965 base 170 took about 15 seconds to get to 60 and topped out at 90 MPH. The modern six cylinder with 193 net horsepower is equivalent to the brake HP ratings of earlier 1960s V8s packing an extra 100 cubic inches, although torque at 225 ft/lbs is not in the same league.

The OOCC Mustang weighs 3,375 pounds which is a lot for such a small car when compared to six cylinder Mustangs of the 1960s. A 1965 Mustang coupe had a curb weight of 2,556 pounds. The 2003 Mustang squarely matches the 1960s intermediates for weight, and those cars had nearly two feet extra length on this Mustang. The computers, catalytic converters, side impact beams, rollover standards, antitheft systems, traction control, ABS, airbags, impact fuel shutoff, and active management systems all add weight.

The other factor contributing to extra weight is the modern trend for a basic car nowadays coming 'fully loaded'. The Mustang has CD player, quadraphonic satellite AM/FM signal seeking stereo which automatically adjusts volume according to vehicle speed, cruise control, A/C, GPS, remote mirrors, power windows, power seats, tilt steering, power door locks, remote keyless entry fobs, remote hood, gas and trunk releases, power sunroof, optional first aid kit, vanity mirrors in both sun visors, webbed overhead storage net, dual cup holders, and on and on.

The OOCC Mustang has a larger six than the old inline six of the 1960s, but it is still a small displacement engine, meaning less fuel and air is pumped through it to start with. The engine management sequential multiport electronic systems squeeze efficiency out of this engine like no carbureted vehicle without a computer could ever hope to do. The engine is a 12 valve overhead valve configuration with a low compression ratio of 9.4:1 able to run on regular 87 octane gas. It still has the factory issue 5W20 fuel efficient thin oil in it, too.

03 mustang engine

The frontal area of the Mustang presents a small, low and aerodynamic profile to cut the wind enhanced by front and rear spoilers. It retains the Mustang look, until you see it parked beside an older one. Then you realize how radically different its shape really is. When you sit in a 2003 Mustang the roof line is right at your head caused by the steep angle of the windshield as it joins the sloped roof, necessary for aerodynamics. The funny thing is, the modern Mustang is higher at the highest point standing 53.1" while the original 1965 has a peak height of 51.1" The modern roll-over standards combined with the raked windshield conspire to create a sense of claustrophobia. The rear seats fold down to allow access to the trunk which improves cargo carrying over the old 1965 although a fastback Mustang from the era with fold down seats may have offered greater room.

The 101.3" wheelbase on the 2003 Mustang is significantly shorter than the 108" wheelbase of a 1965 Mustang. Despite this, the 1965 has a shorter overall length at 181.6". The 5 MPH bumpers on the 2003 stretch its length out to 183.2". Those original Mustangs were narrower, too at a mere 68.2" as compared to the 2003 which is 73.1" wide.

The OOCC Mustang has a 4R70W four speed overdrive automatic transmission which keeps revs very low in high gear using a 0.70 reduction. With the overdrive turned off and running P225/ 55R16s the 3.27:1 axle has the car turning 2,000 RPM at 50 MPH which is comparable to a lot of older cars. Enabling overdrive pushes the speed all the way up to 67.5 MPH at 2,000 RPM. Most 1960s muscle cars were cranking out 3,000 RPM at 65 or 70 MPH. The highway axle 1960s cars might have been running as low as 2,300 at these speeds. Contrast these engine revs to the 2003 Mustang which doesn't turn 3,000 RPM until you are dead on 100 MPH. The little six is rev limited at 115 MPH and 3,500 RPM but is capable of approximately 120 MPH if the rev limiter is disabled. It's a moot point really, because float is noticeable over 110 MPH making it tricky to drive at top speed.

The base 2003 Mustang is mercifully freed of the steel wheel ugly three spoke plastic hubcap combination used on prior base Mustangs. The OOCC Mustang is shod with five spoke clearcoat aluminum mags and 225x16 Goodyear Eagles with fuel efficient compounds and design built in.

All of these factors add up to good gas mileage. The OOCC Mustang managed 22.9 MPG at a sustained cruise speed of 90 MPH on Interstates using cruise control when conditions were clear. There was occasional braking down to 70 MPH while waiting for slower cars to get out of the way, and then the car was floored back up to speed. Secondary highways averaged 70 MPH. The car was pushed up to 100 MPH for fairly long stretches whenever conditions were good enough, with short blasts right up to 115.

The engine speeds are shown below with overdrive enabled:

60 MPH =  1,800 RPM
65 MPH =  1,975 RPM
70 MPH =  2,100 RPM
75 MPH =  2,200 RPM
80 MPH =  2,400 RPM
85 MPH =  2,500 RPM
90 MPH =  2,750 RPM
95 MPH =  2,850 RPM
100 MPH = 3,000 RPM
105 MPH = 3,100 RPM
110 MPH = 3,250 RPM
115 MPH = 3,500 RPM

The weather was warm and dry for most of the road trip. The last two days had light rain with wipers on most of the time. The EPA estimates a 10% decline in MPG on wet roads. Overdrive was on the entire time except for a short stint of driving in mountains. Mountains cut MPG. EPA states that extra fuel used going uphill isn't equaled by fuel saved coasting back down the next hill. The radio was always on, windows rolled up and A/C off. The Mustang was equipped with automatic daytime running lights which sap some fuel due to additional drain on the alternator. The gas tank didn't drop below about 1/4. Gas use varied, listed alphabetically: Chevron, Circle K, Citgo, Exxon Mobil, Wilco- Hess.

The driver, passenger, luggage, food and water came to a total load of about 400 pounds. The Mustang manual states that every additional 400 pounds of load costs the car one MPG, so we could theoretically add one MPG to the figures which interestingly, are the exact recorded numbers posted by a 2000 Mustang (also in the GAS LOGS) driven under similar conditions and speeds with 240 less pounds to haul around.

Odometer Gallons Octane Fill?  MPG (uncorrected)
4,122                    87    Full    N.A. MPG
4,453      13.0        87    Full    26.2 MPG
4,565        5.8        87    Full    19.3 MPG
4,776        9.3        87    Full    22.6 MPG
4,989      10.2        87    Full    20.8 MPG
5,132       5.2         87    Full    27.5 MPG
5,401      11.1        87    Full    24.2 MPG
5,559       6.9         87    Full    22.8 MPG
5,846      13.5        87    Full    21.2 MPG
5,937        3.8        87    Full    23.9 MPG
6,144        8.1        87    Full    25.5 MPG
6,290        6.0        87    Full    24.3 MPG

93 Gallons fill to fill from 4,453 miles to 6,290 miles minus first fill of 13 gals means it took 80 gallons to drive 1,837 miles. That translates to 22.9 MPG HWY average 90 mph.      

Taking each individual fill-up, the total of individually calculated mpg is 258 divided by 11 entries equaling 23.4 MPG overall. Compare this with the other six cylinder 2000 Mustang in the GAS LOGS above or the brutally fast 2004 SVT Mustang Cobra profiled below.


Last Updated ( Thursday, 13 October 2016 18:08 )