I have seen many posts in the MPG threads from people saying they are getting 32-33 MPG when driving 60%-80% city / 40%-20% highway. The best I can coax from my 08 MCS with 2300 miles is 28-29 MPG (hand computed - OBG is always 1-2 MPG higher) under similar driving conditions.

Any opinions or examples of the MPG obtained using the 91 Octane available in California vs. the 93 or even 95 available in other states?

 

In CA here, been getting about the same with an S cooper. Highest so far is 28.9 mpg. Although I've only filled my tank twice so far.

 

The octane rating of gas should have no bearing on the MPG that your car gets.

 

check out this thread...
https://www.northamericanmotoring.co...&highlight=MGP

I'll let you know what I get once I get my car...

 

Colorado has 91 Octane. I'm averaging 34 MPG. It's all about how you drive it.

 

Unfortunately, not many people in that thread posted the octane.

 

I agree, but I also think the type of city driving has a lot to do with it. Part of my 'city driving' consists of waiting at a light for a minute, then accelerating to 45 mph and going 1-5 blocks before stopping at another light. If I accelerate gently and coast to a stop, I can keep it around 27-28 MPG. At other times it's stop and go on the freeway, up to 25 mph then back to zero, averaging 10 mph, with MPG in the low 20s.

I really doubt that two identical cars in good mechanical condition driven exactly the same will vary by more than 1 or 2 MPG. The variablilty in the reports here are probably due to different types of city driving. However, per my first post, I am curious if octane has an impact on MPG.

 

I believe MPG is directly related to ones driving habits.Having said that other variables could be,proper tire pressure,wind conditions,traffic,and probably something else i forgot.|Q