Would taller wheels improve gas mileage?

Back in college, a friend had a set of tires that were too tall for her car (on sharp turns, they rubbed her wheel well, which is pretty dangerous). They affected her mileage, but I don't remember if the affect was negative or positive because this was so long ago.

7 Answers

Relevance
  • Flyer
    Lv 4
    1 decade ago
    Best Answer

    When cruising on the highway at constant speed, bigger tires will result in your engine running at a lower speed...resulting in better fuel economy. But they also will require your engine to down-shift more often when you accelerate...resulting in worse fuel economy overall.

    The larger tires also store more rotational energy that is wasted when you brake...thus a negative for fuel economy in stop-and-go situations.

    They also will cause more wind resistance. You may notice that ultra-high efficiency cars cover the rear wheels to reduce drag caused by wheel rotation.

    Overall, they are a negative. The car was originally designed with a tire radius that matches the engine's performance and transmission's gear ratios. The top gear should result in the ideal cruising speed to minimize down-shifting and maximize fuel efficiency.

    Note: Another answer incorrectly stated that the tires would change a car's power. Increasing tire diameter does not change the car's power. It reduces the car's acceleration by having a larger torque arm...that's not the same as power...it's the same as changing the gear ratio of the transmission to a higher gear.

    As well, one can surmize that if larger tire radii resulted in high fuel economy...the Toyota Prius would have some really huge wheels.

  • Anonymous
    1 decade ago

    It can have both a positive and negative affect. Primarily negative due to the fact that it is a car and doesnt have as much power(assuming) and that the extra weight requires more power to turn the tires. Around town this is worse cause you cant get tho higher speeds where once the car is rolling less power is required to keep the car rolling meaning at the same rpms, the car is travelling further. Car manufacturers now a days always put the most efficient tire size on most vehicles to im prove economy and environmental impact. So really its worse for the fuel mileage. Hope it helps

  • 4 years ago

    Get rid of the 305 and install a 350--bet the mileage improves and so does the performance. You can throw all the stuff at the 305 and will not improve because it doesn't have the power to pull it.

  • 1 decade ago

    To an extent. The most fuel is used during acceleration, so if the tires are too tall you will have to rev the engine higher to accelerate in a way that you expect from that car.

    As long as you drive the car in a very conservative way, it will help.

  • How do you think about the answers? You can sign in to vote the answer.
  • 1 decade ago

    ON FLAT GROUND THE ENGINE WOULD REV LESS AT SPEED, BUT THE ENERGY IT TAKES TO GET THE LARGER TIRE TO THAT SPEED WOULD PROBABLY TAKE AWAY ANY FUEL MILEAGE GAIN.

  • Anonymous
    1 decade ago

    The car goes faster with the bigger tires and it saves little bit of gas.

  • 1 decade ago

    mabe in the old days.... latemodels are designed around tire diameters for best economy....

Still have questions? Get your answers by asking now.