Hi all, I did some searching for this, but I can't find the specific answer I'm looking for. So here goes...

I bought some lightly used wheels for the summer and they already have tires on them. I'm wondering if I can get by with the tires currently on the wheels, or if I should put the stock Dunlops on. Here are the details:

Wheels: Volk GT-V 18x8
Current tires: Nitto NT555 225/40/18 (~400 miles)
Stock tires: Dunlop SP Sport 8090 225/45/18 (~1100 miles)

With the 225/40, we're looking at just under an inch smaller total diameter than the 225/45. I'm a bit concerned at the half inch smaller sidewall on the Nittos for ride quality, problems with the computer systems that use speed data and the looks. A Tire Rack article says to stay within 3% of the stock diameter. This will be about a 4% difference. Maybe I'm being paranoid, but since I have both sets of tires, I could go either way without too much difficulty.

So, should I swap the tires to the Dunlops or leave on the Nittos and just bolt the wheels on?

Thanks for any help anyone can give me!

 

If your putting them on all 4 corners, there won't be a computer problem. The difference between these and the 225/45's is small. The only problem will be that the speedometer will read a little high by a couple of mph. I'm running 245/40's and there is no problem with the ride. You will gain a little quicker acceleration due to the smaller tire. Also gas mileage will suffer slighly.

 

Ya, there is no problem running those tires, just remember your speedo will be out by about 5%. The wheels may appear a bit small, but just make sure you do lots of donuts and have fun trashing those tires so you can put the larger wheels back on later.

 

Haha... yeah, thats what I'm thinking I'll do. The reviews I've read on the Nittos arent all that great, so I'll have some fun burning through them. With the price I got on the wheels, the tires were pretty much free... Of course, now I have to get past 2 sets of tires to upgrade to the 245/40s that I really want.

Thanks for the replies, guys!