CubanoGT

Thanks, yup car had 91

mSaLL150

Yeah, solid numbers for CA 91 winter blend gas. Do it again in 4 months your numbers will be even better.

Mishri

Every now and then I hear someone pop in with a comment on winter gas, I finally decided to look it up. so I guess they are legally allowed to have a higher RVP value in the winter because it wont "boil off" or expand as much in the winter when it's cooler. basically they can add more butane to the mix giving it a higher RVP value than in the summer. The octane rating is completely unchanged, how your engine combusts the gas is unchanged, and power is unchanged. I've read a few articles that also so in no way does winter gas diminish performance. Infact, in the winter you do get better performance. colder air is more dense so there is more oxygen.

I'm not sure where the idea came from of winter gas being worse but I usually hear it from people in CA, is it something they air on the news there? I also saw some articles abut worse gas mileage in the winter. Here that is caused by warming up your car in the morning and extra cautious driving.

btw, summer gas starts june 1st, winter gas starts sept 15th.

mSaLL150

You are probably right about there being little to no performance benefit, however I have lived in CA my whole life and I can tell you I always get better fuel mileage during the summer months than during the winter, no change in driving habits. I have no explanation so I assume its the fuel, but who knows...

clowe1965

Cooler denser air in the winter combined with a static air/fuel ratio yields worse gas mileage. More air=more fuel. I achieved 22 mpg on a tank of gas for a 26-33mpg rated car because i drove it for 3 days during snow weather. without snow i was averaging 28. Extreme example but it clearly points out the temperature effect on gas mileage.

CubanoGT

I didn't even know there was a "winter" and "summer" gas lol my goal for the car was 400rwhp and considering every1 that dyno with me had lower numbers then on other dynos around the area I'm fine with it now I'm going to focus on suspension and looks