Possible to down-size rims and tires on 1999 Pontiac Grand Am?

[southern_slacker]

A friend of mine has the grand am mentioned in the title but he was wondering if he can down-size the rims and tires from 15 rims w/ P215/60R15 tires to some 14 rims with appropriate tires? He wants to do this to improve mileage so any info would help, thanks.

 

[Joe]

You can do it but the speedometer will be completely off if the tire for the 14in rim is not the same overall height as the tire for the 15in rim... Also hes probably not saving much in terms of gas mileage unless he gets lightweight rims but it wont make a noticeable difference.

 

[willie l]

Agreed. The gain in gas mileage would be negligible.

 

[wde3477]

The economy gained would be small, if any. The cost to make the change would likely require many thousands of miles to see the difference. The car was engineered for those tires - some things are best left alone.

Do the simple, cheap stuff - drive like a sane individual, keep the tires aired up to spec, keep the vehicle in good tune.