Different tire sizes on front vs rear axle

tires

#1

I have a 2008 Pontaic G6. I was just given 2 brand new tires size 205/55r16. My current tires are 215/60r16. A friend sent me this link to compare them, but I do not know how to interpret the results.

https://www.tacomaworld.com/tirecalc?width1=215&ratio1=60&rim1=16&width2=205&ratio2=55&rim2=16

Does this change look like it would work for my car if I put these 2 new tires on my rear axle?


#2

I wouldn’t do it, they’re narrower AND shorter. Get the right tires, sell these.

It could be enough to mess up the ABS and stability control. Why risk it?


#3

If the smaller (newer) tires are on the rear, you won’t really be able to tell the difference. However, once you do a tire rotation (you do rotate, them, right?), the smaller ones will be on the front. Hence, you’ll be going slightly slower than your speedo indicates. Without doing the math, this will most likely be marginal, and you’ll also most likely be keeping up with traffic, anyway, so not much to worry about. Just something to be aware of.

Personally, I’d just stick with the man’s recommended sizes. But I’m not you.


#4

This calculator also shows the speedometer will read 65mph when the vehicle is actually going 61.8mph, substantial difference.
Also, the smaller tire probably has a lower load rating than the original.


#5

Using the wrong size tires affects handling and braking enough that I strongly recommend against it.

Thank your friend, but get the right size tires for your car.


#6

Either give the tires back to your friend or sell them. If you sell them, maybe you could take your buddy out to thank him, or split the proceeds. You will be doing the work if you sell them, though, and should keep the lion’s share in that case.

Of course this means you will buy two new tires of the correct size.


#7

Thank you everyone. After reading all the comments, you’ve convinced me to not put them on my car.


#8

Sincere thanks for posting back. And a tip of the hat to you for listening with an open mind.