2004 Mustang Mach 1 E85 Mileage Test - Maize Mileage - E85 Mileage Test

Let's face facts: There are a lot more Fox ('79-'93), SN-95 ('94-'98), New Edge ('99-'04), S197 ('05-'09), and now SN-10 ('10) Mustangs rolling along the world's roads and highways than there are on the racing circuits, and keeping up with the latest info on ways of improving daily driven 'Stangs is the main reason why we do what we do here at 5.0 Mustang & Super Fords.

In most cases, installing parts that are intended to take a Mustang's 5.0-, 4.6-, or 5.4-liter engine beyond its stock performance parameters is the main objective of our tech efforts. However, simply evaluating bolt-on parts is not the plan this time.

In lieu of covering an install, we're looking at the mixture of 85 percent ethanol and gasoline, the alternative fuel better known as E85 (or "corn," if you're Dan Schoneck, one of our King of the Street regulars who swears by the stuff). We attempt to reduce the difference between miles-per-gallon with gasoline and miles-per-gallon using E85, and increase performance (rear-wheel horsepower/torque) with the 105-octane corn.

Assistant Director of State Legislation for the Illinois Farm Bureau-and avid 'Stang enthusiast-Paul Cope is a strong supporter of using renewable fuels in vehicles. Corn is a major crop in the Land of Lincoln, and it's the primary source material used for producing ethanol fuel.

With this being the case, we think it's only appropriate that Paul's bone-stock '04 Mach 1 be used for our study on mileage and performance differences between E85 and gas. We hope the test results will show fellow Mustang enthusiasts the simplicity and potential financial benefit of making the change to corn.

Typically, vehicles using E85 can get anywhere from 20 to 30 percent less mileage than those with engines that run on regular gasoline. However, we believe that simply through tuning, the naturally aspirated 4.6-liter engine in Paul's Mach actually can be made stronger and much more efficient with E85.

Paul, Chuck Spencer, Rick, and Andy all believe a Mustang's computer can be programmed to improve fuel economy (from a cost perspective), and take advantage of its high octane and good combustion properties for more power when the engine is burning E85. We give it a try to find out if it can using the Mach 1's factory tune, as well as Andy's 93-octane and E85 performance tunes. As always, the details on what we find are the reason you should keep reading.

Due to the subject and tests that were performed for this project, this report is a lot more chart-and-data-intense than our usual tech stories. We strongly recommend you pay close attention to the details, as they may lead you to consider going with E85 the next time you fill your 'Stang's tank!

Mileage Breakdown
This certainly is a lot of data to digest, and we totally understand if you're asking yourself what all this means.

Our data reflects the benefit of filling up with E85 when the price difference is narrow, especially as the country continues to pull itself out of an economic slump. Depending on the market, there sometimes is only a 30-cent difference between premium gasoline and E85. (As of this writing, current fuel prices in Central Illinois are $2.83 for premium gas and $2.39 for E85).

On The Dyno
Our off-road testing was done on the Dynojet chassis dyno at Anderson Ford. Andy Wicks of DynoTune (Watertown, South Dakota) worked with Rick Anderson and Danny Biggs, to determine the effect of E85 on Paul Cope's '04 Mach 1, from a performance perspective.

As expected, E85's 12 additional octane (over premium pump gas) opened our test Pony's performance window considerably. We saw nearly 30 peak horsepower and almost 40 additional lb-ft of torque gained at the feet. Andy's DiabloSport ethanol tune kept the air/fuel mixture within close range of the 'Stang's 14.6 average mixture on gasoline.