2018 test2 productsFuel & Additives
Which Engine Fuel Brand Wins?
We compared 2 engine fuel options head to head. Regular gasoline came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.
Winner
Regular gasoline
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The measured results
Every number below is read straight from the test. Scroll sideways to see all measurements. Products are listed in the order they finished.
| Product | Chassis dyno test in a 2003 Chevrolet Suburban 5.3L flex fuel | Real world fuel economy | Projected cost over 100,000 miles versus gasoline | Combustion chamber cleanliness in a small engine | Carburetor and fuel delivery compatibility in a non flex fuel small engine and go kart |
|---|---|---|---|---|---|
| 1E85 ethanol flex fuel, measured close to 85 percent ethanol | at approximately 3,500 RPM produced 312 ft-lb of torque and 221 horsepower versus gasoline's 304 ft-lb and 204 horsepower, a 17 horsepower gain; at approximately 5,000 RPM produced 297 horsepower versus gasoline's 292, a 5 horsepower gain; the torque difference at 5,000 RPM was reported as about 8 ft-lb but the exact per fuel figures were unclear in the transcript, roughly 329 versus 337 | about 11.8 miles per gallon in the Suburban, compared to the host's usual close to 16 mpg on mostly highway driving with gasoline | an extra $2,500 in fuel cost and 80 extra fuel stops | kept the combustion chamber rather clean compared to regular 87 octane fuel, described as a great job of keeping it clean since ethanol is a powerful solvent | engine ran very lean and would not run properly on stock jetting, the main jet had to be drilled out, the original carburetor was already leaking fuel from ethanol damage, engine ultimately ran well after switching to a Tillotson mechanically injected fuel delivery system with an adjustable set screw |
| 2Regular gasoline 87 octane / E10 | at approximately 3,500 RPM produced 304 ft-lb of torque and 204 horsepower versus E85's 312 ft-lb and 221 horsepower; at approximately 5,000 RPM produced 292 horsepower versus E85's 297 | close to 16 mpg on mostly highway driving, the host's usual baseline | not tested | left more deposits than E85 in the small engine comparison | not tested |
How it was tested
- ethanol content verification via water separation test kit
- chassis dynamometer horsepower and torque test in a flex fuel vehicle
- real world fuel economy comparison over several days of driving
- projected cost over 100,000 miles
- combustion chamber cleanliness comparison in a small engine
- carburetor compatibility and fuel delivery test in a non flex fuel small engine and go kart
- flame color observation at different RPM levels
“So, ethanol is a very powerful solvent, so I don't recommend using it unless your vehicle is designed for it.”
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