It is not the different wheel or tires in themselves that give them amunition when arguing a warranty claim. It is when you alter the diameter of the tires. As noted the change from 225/55R18 to 235/55R18 does increase the diameter slightly as so very well documented with actual numbers by an earlier post. I love facts!

Will this change effect anything on the vehicle that should void any warranty claims....not likley. We all know that, but service managers are well trained in spotting items that they can use for leverage to avoid warranty claims.

There should be more 225/55R18 options coming to market in the near future. This a relativley new size to the market and is OE driven. Most tire manufacturers will wait a few years for the replacement demand prior to offering much of anything in that size. I also work in the tire industry. It takes many many $$$$ to bring a new tire to market, even if it is just a new size of an existing line. A singlemold and associated equipment to cure a tire alone can cost in excess of 100K. Multiple molds are used for efficiency purposes. With the profit margin on tires being as small as they are, that requires a lot of tires to be sold to get the ROI.

Just ask yourself...is changing the size of my tires worth a potentialargument over awarranty claim at a later date? 235/55R18.....you should be able win that argument. The industry allows a range for the diameterfor everytire size made.

any 225/55R18 size could have an ODfrom 27.5" to 28.1" with a target of 27.8"
and
any 235/55R18 size could have an ODfrom 27.9" to 28.5" with a target of 28.1"

 

I agree with the above. The original poster was changing all 4 tires to the new size and condition. I think the manufacturer would have more problems if 2 tires were differentsizes than the other 2. I don't think ABS, traction control and AWD systems like different rotating diameters. If all 4 tires are rotating the same, larger diameter and not scraping anywhere(at full spring compression, etc), it shouldn't be a problem.