Thread: MAX tire size
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Old 09-10-2012, 03:07 AM
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Originally Posted by EODtruck View Post
I am having a big issue finding a straight answer, on all the dodge ram forums. All I am trying to find out is the max tire size that will fit a 4th gen 1500, 4x4, 20x9 inch, no level or lift. I mean, sticking with 33"s, so basiclly my concern is the width. Rims are stock, so no spacers either.

I can get a really good deal on a set of tires, but the only size in 20's is 33x12.50R20. The tire place said they should fit, but I don't trust him.

Using one of the standard to metric converter, a 33x12.50R20 equates to 318 52 R20 (315 50 R20 I would guess??). Will a 315 50 R20 fit, if not any suggestions?

You will need a 1/4 spacer in order to fit those tires without rubbing on the suspension. I ran 35x12.5x20's on stock 20x9 ram wheels, but a I had a 1.25" spacer for a wider stance with the lift.

Originally Posted by RamSport View Post
Why dont you tell the tire dealer to install the tires but that if they rub you dont want them. I really dont think they will rub at all. A 13.50 maybe but not a 12.50. And i dont think a 33 12.50 is equal to a 315. A 33 inch is more equal to a 285. A 315 would b closer to a 35 inch tire.
Like EODtruck;882745 stated 33x12.5x20 = roughly 317x52x20 or the closest acual tire sizes would be 315x50x20 which is 32.79" tall by 12.4" wide, or 325x50x20 which is 32.79" tall by 12.79" wide. One inch equals just over 25mm (25.4) so a tire that is 255x50x20 is just over 10" wide.

Originally Posted by fastNugly View Post
Straight answer here.
You will rub for sure with 33x12.5 tires on stock wheels.
That is 100%

Heck, even at 295/60/20 tires you'll rub. Which is a 34" tire
You will require spacers for either setup or an aftermarket rim with negative offset.

Stock rims are 20x9, +19 offset.

If you don't believe me, take your tape measure and measure from your tire to your A arm. You have max 1/2" space till it rubs.

Many members here are running 295/60 and 33/12.5 tires and 295 requires 1/4" spacer and 33x12.5 requires a larger spacer but anything more than 1/4" I recommend another set of aftermarket rims with lower offset. Like a 0 offset.

295/60 = 0.4" wider on either side of wha you have now
305/55 = 0.6" wider on either side.
315/55 = 0.8" " " " "

You have to do either of the following or a combo depending on tire size selected.
- level your truck
- use spacers
- get aftermarket rims

Cheapest of the 3 is 1/4" spacers and then leveling.

Its not more so the height, rather the width...again pertaining to the tire sizes mentioned above.
Hope this helps
This right here
You need either a lower offset wheel (by either getting new wheels or adding a spacer) or a narrower tire so it wont rub.
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