[hockeymaniak88]

I'm buyin tires for the grand prix and I was reading reviews about a pair of Goodyear Assurance Triple Tred. I love the tread pattern and performance but a few people said that their gas mileage went down between 1.5-2 mpg after they installed the goodyears. I looked up the specs and it turns out the goodyears weigh 4 more pounds per tire than the stock bridgestones.

The only thing I could think of is that people drive the car harder because the tires perform/handle/look great OR adding weight to the actual powertrain does affect performance. After all reducing drivetrain weight is the main proponent of aluminum flywheels and driveshafts....Is there any truth to this?

[stlwagon]

You bet. Heavy wheels & tires can certainly lower your mpg.

[dakine858]

Anytime you add something heavier to your car, your engine has to work harder to move the extra added weight, thus lowering gas mileage.

[fox89mustang5.0]

Yeah u can bet heavy tires will lower your gas mileage. All you have to think of is the heavier it is the more friction there will be which would lead to a loss in gas mileage and that because its that much harder your engine has to work to get your car moving.

[stlwagon]

That's why drag racers are always looking for a lighter wheel (well, not for gas mileage, but you get the idea)