Engine Fuel Oct 2018 Test: Which Brand Wins?
In our Oct 2018 test 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.
Regular gasoline
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The quick take
The short version of why each pick lands where it does, built straight from the measured results.
“So, ethanol is a very powerful solvent, so I don't recommend using it unless your vehicle is designed for it.”
The measured results
Every number below is read straight from the test. Products are listed in the order they finished.
All measurements (5 more)+
Chassis dyno test in a 2003 Chevrolet Suburban 5.3L flex fuel
- 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
- 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
Real world fuel economy
- 1E85 ethanol flex fuel, measured close to 85 percent ethanolabout11.8
miles per gallon in the Suburban, compared to the host's usual close to 16 mpg on mostly highway driving with gasoline
- 2Regular gasoline 87 octane / E10close to16 mpg
on mostly highway driving, the host's usual baseline
Combustion chamber cleanliness in a small engine
- 1E85 ethanol flex fuel, measured close to 85 percent ethanol
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
- 2Regular gasoline 87 octane / E10
left more deposits than E85 in the small engine comparison
Projected cost over 100,000 miles versus gasoline
- 1E85 ethanol flex fuel, measured close to 85 percent ethanol
an extra $2,500 in fuel cost and 80 extra fuel stops
- 2Regular gasoline 87 octane / E10not tested
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
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 / E10not 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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Which Gasoline Octane Grade Brand Wins?
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