Larger tires decrease gas mileage, larger wheels decrease acceleration

[Victor]

Article in today's LA Times says pimping your car with bigger rims and wider low profile tires decreases gas mileage. Says 20% of your fuel goes to overcoming rolling resistance from tires. The bigger and wider the tire, the more rolling resistance. Article says also to not use rain tires if you drive on mostly dry roads. Also, worn tires get better gas mileage than new tires since they have less tread on them, plus are smaller diameter. The larger the rim size, the worse the performance because of rotational inertia being much higher for a 17 or 20 inch rim than a 15 or 16 inch. The lighter the wheel the better, like the forged rims on a J30T being much better for performance than heavier cast rims. There can be as much as a 10% difference in gas mileage between using best and worst tire for your car. Generally one should stick with the tires that the car manufacturer supplied when new. Large tires are also less aerodynamic than smaller tires, adding extra air resistance to the rolling resistance. Article says the tire industry is fighting a proposed law to make them list the rolling resistance of their tires.

[driverdriver]

It makes sense, wider tires and larger rims will increase the contact patch with the road and distribute more on road weight, which requires greater effort to move.

[brandonjustice93J30]

hrrrm...*ponders* 145/70-12's on steel rims from a Geo, aired up to 50psi......

j/k

[yodawill2000]

No need to post this on different forums.Most of us are aware of that anyway.Simple Physics.

lol@ brandon.Maybe bicycle tires ??

[kbflip02]

hrrrm...*ponders* 145/70-12's on steel rims from a Geo, aired up to 50psi......

j/k

[brandonjustice93J30]

ooooh....I'll even put the spokies...those little things that slid up and down the spokes and made clicking noises.....and the baseball card in the spokes