AAA tested the old premium vs. regular question for cars that recommend, but do not require premium. Both regular and premium had 10% ethanol in their tests BTW.
https://newsroom.aaa.com/2017/12/dont-fueled-premium-not-always-worth-price/
Quote:
Fuel economy for test vehicles averaged a 2.7 percent improvement. Individual vehicle test result averages ranged from a decrease of 1 percent (2016 Audi A3) to an improvement of 7.1 percent (2016 Cadillac Escalade).
Horsepower for test vehicles averaged an increase of 1.4 percent. Individual vehicle test result averages ranged from a decrease of 0.3 percent (2016 Jeep Renegade) to an improvement of 3.2 percent (2017 Ford Mustang).
Full Report https://newsroom.aaa.com/wp-content/uplo...ort-FINAL-2.pdf
Interestingly for the Audi there was more mpg with regular gas, however the engine produced a "harsh audible engine knock in road driving using regular gasoline" so the engine was not able to prevent knock.
I was looking at the charts at the back of the report and a lot of the cars had a lower catalyst temperatures with premium gas. How would premium gas lower the catalyst temperature?
https://newsroom.aaa.com/2017/12/dont-fueled-premium-not-always-worth-price/
Quote:
Fuel economy for test vehicles averaged a 2.7 percent improvement. Individual vehicle test result averages ranged from a decrease of 1 percent (2016 Audi A3) to an improvement of 7.1 percent (2016 Cadillac Escalade).
Horsepower for test vehicles averaged an increase of 1.4 percent. Individual vehicle test result averages ranged from a decrease of 0.3 percent (2016 Jeep Renegade) to an improvement of 3.2 percent (2017 Ford Mustang).
Full Report https://newsroom.aaa.com/wp-content/uplo...ort-FINAL-2.pdf
Interestingly for the Audi there was more mpg with regular gas, however the engine produced a "harsh audible engine knock in road driving using regular gasoline" so the engine was not able to prevent knock.
I was looking at the charts at the back of the report and a lot of the cars had a lower catalyst temperatures with premium gas. How would premium gas lower the catalyst temperature?