If I install larger tires on my vehicle will it increase the mileage?

Question

OK. I was thinking of installing large tires on my vehicle, large like increasing the circumference or something. Say if the diameter of the tire now is 1 inch, I am thinking of making it 1.1 inch. I was thinking that since more length will be covered on every revolution of the wheel and the revolutions are going to remain the same, will it increase the mileage? Thanks for your answers.

Answer 1

Changing the tire size, changes the overall drive ratio.  Larger tires, reduce engine RPM, for a given road speed.  However, torque will be greater.  This could result in better gas mileage, at a performance cost.  It could also produce poorer gas mileage.

If you have a manual transmission, you may find yourself staying in a lower gear longer, to compensate for the larger tire size.  If you have an automatic transmission, you may find it stays in a lower gear longer, and downshifts more readily on a hill.

Ideally, what you are trying to accomplish, is handled by selecting the final drive ratio, when the vehicle is purchased, provided the manufacturer offers the option.  Some buses and trucks, have been known to have two speed differentials, to allow for varied terrain, and varied load.

Regardless, what is more significant, is, you will change the handling characteristics of the vehicle.  Larger tires, will raise the center of gravity, increasing the propensity to roll over,  very significant for pickup trucks and SUVs.  Furthermore, you will also affect braking characteristics, and traction characteristics of the vehicle, particularly in the rain.  Lastly, you may encounter clearance problems in the wheel wells.

Answer 2

No it wont affect mileage but it affects mpg.

Larger tires may give you better gas milage (like an overdrive gear) but they will also throw your speedometer off, so you will have a hard time measuring the gain. They will also slow your acceleration

Answer 3

maybe.  but you'll face other issues when you do it.

pros.  fewer RPM, perhaps better fuel economy as a result

cons.  typically taller tires are wider, so the friction of the wider tire negates any gain in dropped RPM.  the tires will also be heavier, and your gear ratio off, so your engine will work harder at lower speeds...   finally, this will raise the height of your car which means you now have a larger frontal area (which has a squared net affect) and a larger low pressure behind the car which increases drag.  

generally overall the answer is NO, it can actually hurt your fuel economy, but that is not always the case.

Answer 4

Simply put, the gain would be canceled by the extra load on the engine.

Answer 5

Some good answers already, I'd just like to add that the cost of four new tires would probably be more than what you would save at the gas pumps.

You're better off just making sure that your current tires are always properly inflated.

Answer 6

Nope, the best mileage cars on the road have no bigger than 15" wheels and skinny not so tall tires.