Chetrey

Standard size in Front 225/40-18 & Rear 285/30-18. Can I use a Front 255/45R19 & Rear 285/40R19? Can’t find pros/cons info. Especially going from 225 to 255 in front and 18” to 19”

NuttyProfessor

Those fronts will more than likely scrub. The stock aspect ratio is 40; therefore, if go to a 45 series with increased width, it will scrub. I've experienced this personally. These cars were never designed for 19" wheels to begin with, but that doesn't mean you can't make it work. You'd need to decrease the tire sizes to accommodate.

Here's my guess - front - 225/35/19 rear 285/25/19 (you may have to go with 285/30/19)

Be careful with the wheels you choose. Make sure they're the right offset.

996.2

We increased front tire size +10mm to 235/40/18 and at full lock both front tires touch middle of fender liners on the front. Size of stock wheel wells don't seem to allow larger diameter than 225/40/18.

In future will check if anything is directly against front of wheel well, and if not will try to form a depression maybe 4" square and 1/4" deep so tire will have zero contact.

ricardofors

I'm using 235/35-19 in front and 295/30-19 rears. Offset and ride height will be key here. Even tire dimensions could be a factor. I agree that an aspect ratio of 45 would be too high of a side wall, with the right offset you could do 255 tire but you will be adding camber to avoid fender rubbing issues.

sgt1372

I've got 19's on my new to me 2000 C4 Cab.

They're Nexen's (which is one reason I'm thinking of getting rid of them, see below). I forget what sizes they are but they don't rub (front or back). Will have to look and post later.

Also don't know if there are spacers behind the wheels; haven't looked yet but don't plan to do that any time soon unless absolutely necessary or until I get the hollow twists, whichever comes sooner.

Actually am planning to buy a set of 18" OEM hollow turbo twists and to put a set of Michelin Pilot Sport 4S on them but I'm in no rush to spend the roughly $3k that will cost.

langg

Remember that you want to keep the outside diameter front to rear within 3%-4% max for the C4.