545 gas mileage

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Jul 4, 2005 | 09:00 AM

#71

grogan545

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From: southestern pa

My Ride: 2008 550I,manufactured 2-27-08,delivered 4-2-08.Platinum bronze,natural brown interior,light poplar trim,cold weather package,heated rear seats,HD radio

Quote:

Originally Posted by UUronL' date='Jul 3 2005, 10:06 AM

[quote name='Jeffs' date='Jul 2 2005, 05:46 PM']hahahahah yeah.....im just bewildered how people get such good gas mileage...i drive conservatively and my commute consists mostly of highways but....i still cant get 20mpg....

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After a few fillups with the lower tire pressure, I can say that -not- running the highest load pressures will result in a decrease in fuel economy of up to 5 MPG. I switched mine from 44/36 to 35/29 and I went from about 27MPG to barely over 22MPG. Same driving and routes. I've waited to see it trend over about 3 fillups before reporting. Oh, and with the lower pressures, the computer seems to be spot on with my hand calculations.

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mileage decrease with lower tire pressure pressure seems normal although dropping from 27 to 22 seems a bit much.can't explain why the computer calculations would be more accurate though.lower tire pressure should decrease the tire diameter which should increase the error in the odometer which in turn should increase the error in fuel calculation by the obc.