How do rims affect car performance

We can treat the torque value as a constant assuming your engine produces a stable torque figure which therefore means that if the wheel radius changes, the driving force acting from the wheel must also change. Now, increase that wheel diameter to a set of inch Need for Speed style, fake diamond cut rims from your local Halfords.

Run the calculation through again and that driving force will decrease to Newtons. So, increasing your wheel size will decrease the driving force from your wheels which will culminate in a decrease in acceleration of said wheels. This is all assuming that every other component like the engine, driveshafts, gears and differentials are kept stock, making them specifically engineered for the original wheel size. Car and Driver ran an interesting test a few years ago to show just how much difference wheel sizes can make to acceleration using a VW Golf.

The car was tested with varying wheel sizes, with the mph times ranging from 7. That lag in time was emphasised with the mph times as well, with the large-wheeled car taking over a second longer than the inch variant. By way of comparison, we can say can consider the total wheel diameter as the length of the final reduction ratio of the transmission.

Increasing the total wheel diameter will also increase the final reduction ratio and this has essentially two consequences: acceleration potential is decreased but a higher top speed can be reached. Naturally, these changes are directly proportional to the variation of size. The consequences of a few millimetres of difference may be virtually undetectable, while more radical changes may cause much more obvious variations.

But there is another element to be taken into consideration: increasing the wheel diameter will also increase the axle weight as a whole.

This will obviously increase inertia, cause further loss of acceleration and also lower cornering accuracy. The behaviour of the car may also change: increasing the tyre diameter will obviously raise the chassis height and the centre of gravity as a consequence, with the direct effect of increasing roll and oscillations.

There are consequences of increasing the tread width as well. Above all, a larger width will contribute to increasing friction. It also means that the rolling resistance will be higher and more will be energy required to move it. Bigger wheels make your car look more masculine but not all vehicles are meant to look so. It is important that the wheels fit in the wheel arches. Under wheeled as well as over wheeled cars can be quite unpleasant to look at. Sometimes, by just changing the brand or type of tyres, you can get a new look for your car without having to change whole wheels.

For example, larger tires decrease your fuel economy because they are heavier, while smaller tires increase fuel efficiency. Bigger tires also have a higher rolling resistance than smaller tires which means they require more resistance and effort to get them rolling. Do bigger rims affect speed? The diameter of a larger wheel means that its circumference is larger. So, a larger wheel will actually turn slower, but move a vehicle forward faster than a smaller wheel.

The smaller wheel will take less torque to get moving, but the larger wheel will give a faster overall speed. Can I replace 15 inch wheels with 17 inch? Does bigger rims make car slower? A larger wheel will result in slower acceleration and higher top speed if the engine has enough power.

If not, at least the top speeds in each gear but the last will be higher. Will bigger tires affect my transmission? The increased size causes the tires to rotate slower to cover the same amount of ground. If you are running an automotive transmission this can cause some serious strain depending on the current gear ratio if you choose not to regear your system.

Are 20 inch wheels better than 19? For a given wheel, 20" will weigh more and the ride will be worse.