gas
Race Director
Joined: May 2006
Posts: 10,691
Likes: 71
From: Phoenix Arizona
If it doesn't run good on regular, you probably have other problems.
That said, it often runs better on the higher octanes. The computer retards the spark if it detects pre-ignition that sometimes happens with regular gas. The newer cars get better mileage with higher octanes, because they have higher compression ratios. Does it mean cheaper total cost....sometimes. Premium usually costs about 10% more. Does regular hurt your engine? No.
That said, it often runs better on the higher octanes. The computer retards the spark if it detects pre-ignition that sometimes happens with regular gas. The newer cars get better mileage with higher octanes, because they have higher compression ratios. Does it mean cheaper total cost....sometimes. Premium usually costs about 10% more. Does regular hurt your engine? No.
