well, i have ADVAN RG-2 wheels on my car. 17" width of front is 7.5" while rear width is 8.5"

i want to change my setup when i buy new tires from 225/45 fronts and 255/40 rears.(current setup)

to 235mm front tires and 255 rears.



should i get 235/45 or 235/40?

my car is lowered 1.5 inches and i want to change the setup to reduce understeer.
i know that the tire profile is a % of the tire width, so if i keep the profile at 45 while increase the tire width im going to end up with a higher profile. but im afraid that if i reduce the profile number to 40 the profile will get much lower.

thank you

 

i say get the 45 series if your worried about the car getting lower...i went with a 235/40 and i kind of don't like how low the front end has gotten

 

235/40. That is the closest to stock diameter and sidewall profile is almost identical. Also, if you went with a 235/45 your front diameter would be larger than the rear.

 

thank you for the input. i think ill go for 235/40/17 coz i dont want the tire to rub with the fender too. but in this case the rear tires diameter will be a little bigger than the fronts since the rear tires are 255/40.


i have another idea! will it fit well if i put 245/40/17 for my 7.5"front wheels? this size will have closer diameter to stock and ill eliminate the understeer.

 

It should work. A 245 tire on a 7.5" wheel is pushing it though, probably have a little sidewall bulge. Also, depending on the offset of your wheel you might have rubbing issues.

 

yeah that would make another issue. weak sidewall support and bad streering response. i think in my case, with the wheels i have, i should opt for the 235/40

 

235/45 and 255/40 should be more or less the same sidewall thickness/tire diameter. If you do 235/40 and 255/40 your rear tires will be much "taller" (overall diameter will be larger due to a much taller sidewall) and you'll get a bit of rake as a result. It looks rather aggressive but can be overdone and as a result look silly.

Personally, I'd go with 235/45 and 255/40.

 

I'd go 235/40. Having the fronts 16mm smaller in diameter than the rears looks better than having the fronts 7.5mm larger in diameter than the rears. Plus less chance of rubbing issues.

 

Ah crap sorry I didn't do the math this time, I made a poor assumption that the 235/45 and 255/40 would be more or less the same overall diameter.

After actually doing the math, I would run 235/40 and 255/40 for sure.

 

thank you everybody. i appreciate your help