I am slowly looking at replacement tires for my '06 sedan. I know the stock tire size has very little choices, but I would like to know if I can put another size on my OEM 18" wheels to get a better selection of tires. Please let me know what brand tire you have been using to replace your tires.

 

If you want the same size, Kumho SPT's are a great tire for the price, way better than the goodyear NCT-5. On ebay there is this new brand called fierce by goodyear but I do not know if they are any good.
The two sizes that a very close are:
245/40/18 will work but are a little short
245/45/18 will work but are a lttle tall

 

245/40
Bridgestone S03 pp
Bridgestone RE750
Bridgestone RE960AS pp

I've used all of them, the S03's are by far my favorite, to bad they're discontinued
-GP-

 

I have heard the best bang for the buck tires were the General Exclaims UHPs. I have yet to try them or even buy a General tire for any of the cars that I have had but alot of people swear by them. I was looking at either them or Nitto 555s when I replace mine and I plan on going with 245/45/18s to help fill the gap a little.

 

I just ran about 5K miles this summer on General Exclaim UHP's. They are great. Smooth, handle well and have a long life rating. (380 I believe) If it matters to anyone, the set on my car say Made in Germany. General is owned by Continental, so I think that is who is making this tire. I went 245/45/18 and they do fill the wheel well nicely on my X. As a plus, my external GPS tells me what speed I am travelling. With the stock 17" rims and 215/55/17's the speedo reads 80 but the GPS says I'm doing 76. With the Generals, the speeds match exactly.

 

How much taller are the 245/45/18 tire. I am going to be dropping my car with 350z springs.

 

bump

 

the diameter is only 4/10 of an inch bigger. the speedo would 1.3% too slow. you can mess around with different sizes and see the comparison on the miata tire calculator.

 

I just installed the Continental ContiExtremeContact 245/45ZR18 and they feel great so far.

 

The Kumho SPT is a GREAT tire. Good price, great traction. I have been running them now for several months and absolutely love them! I use 235/45/18's on my lowered 2003 sedan. GO KUMHO - you won't be disappointed.

tD

 

245/40-18 should not be put on 18x7.5" rims - minimal recommended rim width for that tire size is 8".

 

I just did the same and have no complaints.