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Discussion Starter #1
So after upgrading to 20s from factory 15s, I noticed that my MPGs on my car were horribly low. With the 15s my car averaged 21.8 (22 in the city is factory rating), and now with the 20s my car is getting roughly 18.0-18.2 MPG. The thing that throws me off is I called ford and they said that it was about 100 more pounds on your car so it would affect your gas mileage by 2%. So if we take 22 x .02 = .44 decrease, which should give me 21.56. How is it that I am getting 18 MPG. Any suggestions? :(
 

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But 3mpg is not bad for upgrading from 15' to 20' and ford might o just thrown that 2% number at you
 

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Discussion Starter #5
But 3mpg is not bad for upgrading from 15' to 20' and ford might o just thrown that 2% number at you
I dont think so. 4 MPGs for just 100 pounds? that just doesnt seem right at all...
 

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Discussion Starter #7
More tire to rotate heavier rim. But maybe you've been driving with a heavier foot??
I dont think ive gotten on it enough to make a 4 mpg difference :D but idk about the tire. it could be a possibility but again a 4mpg difference?
 

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Is your overall tire height different. If so you may have changed your wheel RPMs. Is your speedo off, or did you retune?
 

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My God! You are now down to 18mpg!!!!

You better sell that Gas Robbing monster before you go broke!

Check you tire pressure.
 

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Abominable Mustang
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You will lose some mpg because of the larger wheels but it shouldn't be THAT much.

Is your overall tire height different. If so you may have changed your wheel RPMs. Is your speedo off, or did you retune?
I was just thinking that. If the revolutions per mile have changed, your speedometer and odometer may not be accurate anymore.

Do you know the new and old tire sizes?
 

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Discussion Starter #11
Is your overall tire height different. If so you may have changed your wheel RPMs. Is your speedo off, or did you retune?
I'm sure speedo is off and no I havent calibrated it yet

---------- Post added at 03:36 PM ---------- Previous post was at 03:35 PM ----------

My God! You are now down to 18mpg!!!!

You better sell that Gas Robbing monster before you go broke!

Check you tire pressure.
Bad joke...and tires are a week old and all are at required tire pressure
 

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Yeah I've got the GT/CS 18X8.5" wheels stock compared to my buddy's stock 16" base wheels and he gets like 2mpg better city
 

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Discussion Starter #17
Welp, talked to AM and I'm just going to send them back, but on the bright side I can start saving for a turbo lol
 

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Discussion Starter #19
Wmcgrattan said:
Buy some clean take offs from someone an save the money for the turbo !
Ding ding ding! Your right! Saving up for a turbo. Project pshhhhh
 
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