06 MR/T- Biggest 20'' Tire?????

[Magnum R/Texas]

I wanna get 20'' rims for my 2006 Magnum R/T for the performance quality. I hate empty fender space, so whats the biggest tires i could put on the 20'' without modifyin or having certain mm spacing. Also want all four same size for rotating purposes

[charginscott]

I guess that would depend on the rim width....oops missread that...There are pretty tall truck tires being as we have truck size tires to begin with - lolol

[Magnum R/Texas]

Ok well just to make sure, The 255 is the side wall height. The 45 is the wideness and the 20 is the rim size. I'm pretty sure thats right, but is the middle number, Higher the number=Wider the tire?

[LIL WAGON]

I thought it was the other way around 255 width 45 is height and 20 rim size

[Magnum R/Texas]

Yeah your correct, I had it backwards. 255 is the width of tire in mm, 45 is distance between rim and tread and 20 is Rim size. So I think I may want a 275 for a fat wide tire 50 to fill fender up and 20 as my rim size

[89grand]

Yeah your correct, I had it backwards. 255 is the width of tire in mm, 45 is distance between rim and tread and 20 is Rim size. So I think I may want a 275 for a fat wide tire 50 to fill fender up and 20 as my rim size

You don't want a 275/50/20. That tire is way too tall, it's 30.83" tall!

A 275/40/20 is what you'd want if you want a 275 wide tire. I went with a 255/45/20 because I think the slightly taller tire fills the wheel well better.

The only real 20" tire options you have for the same size front and rear are:

245/45/20 = 28.68" tall
275/40/20 = 28.66" tall
255/45/20 = 29.04" tall

I even think the 265/50/20 is too tall at 30.43" tall.

[L-Town RT]

So your saying a 275 40 20 will fit without rubbing?

[dudeiwin86]

fyi.
take 275/40/20
275 = width of tire in mm
40 = side wall height in mm, based on percentage of width. in this case.. 40% of 275mm
20 = radius of wheel it goes on.

275/35/20 has a side wall height 35% of the width.


i have 275/40/20 on a 8.5" rim. cant remember the offset but it does rub a tiny bit on the front. well.. it did when the tires were brand new.
it would only rub up front on cornering where the suspension was compressed, and the wheel was turned pretty hard.

it has never rubbed in the back.

[89grand]

If you take the tire width say 275 then mulitply it by the aspect ratio 40, then divide by 25.4 then multiply by 2 than add wheel size will get you the tire height and the side wall height.

In other words 275mm X 40% = 110mm divided by 25.4 (to covert to inches) = 4.33" (side wall height). Then take 4.33 x 2 = 8.66 + 20 for the wheel = 28.66, for the total tire size.