Crap, i think i made a 400 dollar mistake - Corolland: the Toyota Corolla Forums

Guest SpiceWeasel

I think i made a 400 dollar mistake getting the wrong tire size for my car. I got 205/50/15's. Does this affect how fast the car accelerates / decellerates. I also read in a nother post that the wrong size tire might gie me false spedometer readings? Also i got my butt handed to me by my bros stock 115hp civic, dunno if the tire size would have something to do with this, as im sure i mentioned i am a noob. On the plus side the new rubber handles/great, even in the rain, its a big improvement on the goodyear integras i had before.

Your tire size of 205/50R15 are about 586mm in diameter - the OEM tire size is 185/65R14 which is about 596mm in diameter.

In the 15 inch wheel - 195/55R15 is the preferred "plus 1" size.

The tire you have is a bit wider than it should be for the wheel size - not a huge problem, but will reduce fuel economy slightly and cause acceleration to be a bit more sluggish due to the higher drag and grip. On the plus side - your deceleration and cornering should be much better because of the larger contact patch.

As for speedometer readings - it could be off by a few percent - not much to be worried about, but it will read slightly higher than what the OEM tire will read and you will actually make the car work harder over the same distance because the tire is smaller.

As for getting burned by a Civic - depends on the weight of the wheel + tire package - if heavier than stock, you are giving up some performance due to the increased unsprung weight. If lighter than stock - you have a problem of the tire creating too much aerodynamic drag. Both will equal more fuel consumption and lower performance.