Pit5Bull

I was thinking about this the other day and was wondering if there's any correlation between low profile tires on larger wheels and cracks in the wheels as a result of normal, city driving.

I imagine that most of us do a lot of city driving, and we all know of the routes that have rougher roads than others, and those of us with aftermarket wheels and low-profile tires pay particularly close attention to the road so we don't make an expensive mistake and screw up our investments. We can't always avoid the hazards in the road, but I believe in prevention and think it's always best to be prepared in case of an unforseen asphalt bulge or a brand new pothole on the way into the office...

In order to keep our speedometers accurate and protect our wheels from adverse road condtions, what's the main thing to look for when purchasing tires when we have to go with a lower profile due to larger wheels. I have 18x8 MKW M12s on a set of Dunlop 215/40/ZR-18s and have developed a crack in one of my wheels, but I can't think of how it could have happened or where, as I'm one of those who pay particular attention to where I'm driving and where all the asphalt bumps, potholes & road wrinkles are on the paths I drive from here and there.

I've been told that I should at least run 225's and am looking into 235's, but I have to get my wheel repaired/replaced before I look into replacing the tires. I only use these wheels during the spring/summer months anyway, and I don't drive particularly hard, as a rule, although I am planning to do a few performance upgrades on the car once it's paid off in just under 2 years...

As always, your input and opinions are appreciated. Thanks in advance

upstatemax

iTrader: (15)

What were the original rims on your car the 15's or 16's?

Either way I would look at 225/45/18's, you will get more sidewall to protect the rim.

Pit5Bull

@upstatemax...

I had the stock steelies on there - 15's. I'm using them now until I get my wheel replaced/repaired, and the wheels I have are 18x8. I think the tire calculator sites I've visited mentioned that if the stock-to-aftermarket wheel diameter ratio was over 1% in either direction that it wasn't a recommended size, and if I remember correctly, a 45-series tire on an 18" wheel was over 1% larger than the stock diameter wheel with stock tires. I could be wrong, but I remember checking that out and writing it down somewhere...

upstatemax

iTrader: (15)

In that case it says that your size would be off about 1.9%, that is more than fine. Mine is off by about 2.1% (225/50/17 ---> 235/45/17) and it is fine.

vansterdam

This tire calculator recommends staying within 3% of stock tire height.