17/19mpg avg to 25/28mpg?!

[Paul32]

I have compared more than 50 fill up's and all were optimistic based on the car's computers. If there were variables in the pump fill ups, one would think they would be plus and minus. I'll rely on my calculation like I have been doing for the past 60 plus years. Every car I have ever owned with a computer was optimistic.

My GT1, 13 fill up since new, 1.6 mpg avg optimistic. Range has been from .9 to 2.9, there's your pump variable. But all ways on the plus side.

 

[SilverNitr8]

Please just stop blaming low avg mpg based on octane. I've filled up my car with 91 twice and averaged 15 mpg on mostly city driving. I tried 87 and same results, driving on comfort. I took a 167 mile trip on mostly highway using 87 with speed around 80-95 mph and averaged around 26.7 mpg. There are a lot of factor that affects your averaged mpg like traffic, acceleration, etc... If you want to know your true average mpg, I recommend calculating by hand and try it without traffic then see if it made any difference. For me, no difference whatsoever.

 

[rocket23]

eliminating factors (such as different fuels) will result in more confirming result

 

[Tonkabob]

I disagree. I put on rotary forged wheels that saved 10lbs on each wheel. I saw no real mpg improvement.

Didn it make your car any faster or improve handling? 40 lbs rotational weight is alot.

 

[Never thought]

Didn it make your car any faster or improve handling? 40 lbs rotational weight is alot.

Not that I could tell. But I don’t push my car super hard. And I am used to a turbo Optima so the car just feels way fast. Also, I had a bent wheel for about a few thousand miles which jacked up the handling so I don’t have much to compare to.