What about 275/45R20?

razteo · Oct 2, 2017

I just bought a 2017 R/T with:
- Super Track Pack
- WRT black wheels 9"

The car came with the 245 tires (see below picture) and I want to go & get the 275's all around.
After searching a bunch of posts on this forum, I still have a couple of questions:

1. Will the 275's fit without rubbing at all 4 corners?
2. Why is everybody here getting the 275/40R20 and not the 275/45R20? The stock tires are just fine on 45, so is there any reason to not go with the 45 on the 275's? WIll they rub on the 45?

Thanks in advance for your answer.

Cuda340 · Oct 2, 2017

The diameter of a stock 245/45-20 tire is 28.68 inches and the revs per mile is 725.22.

When you are buying a larger width replacement tire, you want to try to match these numbers to keep your speedometer accurate.

A 275/45-20 tire will have a larger diameter of 29.74 inches and the revs will be 699.30. This will make your speedometer read slow by 3.71%. A better choice would be the 275/40-20 tire. Its diameter is nearly identical to the 245 tire, at 28.66 inches. Also, the revs are 725.71. In this case, the speedometer will read slightly fast by only 0.07%.

Check out this tire size calculator:

http://www.1010tires.com/Tools/Tire-Size-Calculator/245-45R20/275-45R20/275-40R20?ismetric=False

John Matthews · Oct 2, 2017

Fitment is not an issue. When I went the 270 route there were a lot more choices in the 40 then 45 series locally.

chris1992 · Oct 2, 2017

The 40 and 45 number you are referencing is the aspect ratio. This number should not be used alone to determine the height of a tire, the height of a tire is based off both the aspect ratio and tire width. This is why a 245/45 and a 275/40 are nearly identical in height.

(245 x 0.45 = 110.25mm ; 275 x 0.40 = 110mm)

razteo · Oct 2, 2017

Great info, thank you.
It looks like the 270/40-20 is the way to go then.

So again - no fitment issues with the 275s, no rubbing when turning, or in the rear over bumps, etc.?

Knukey · Oct 2, 2017

Discounttiredirect has a feature that lists optional sizes that "fit". I clicked on 265/45-20 and those listed were $202/ea and UP. Ninety (94) options pop up on 275/40-20 starting at $95/ea.

245/45-20
235/45-20
255/45-20
265/45-20
255/35-20
235/40-20
245/40-20
255/40-20

razteo · Oct 3, 2017

Thank you.
The R/T is at the shop as we speak and 275 Falkens are been installed.
Can't wait!

Jermetheus · Jan 21, 2020

razteo said:
Thank you.
The R/T is at the shop as we speak and 275 Falkens are been installed.
Can't wait!

Please post pictures

Knukey · Oct 3, 2017

Post a pic.

razteo · Oct 4, 2017

Here you go, 275 Falkens:

19TRPLNICKL1320 · Jan 22, 2020

Very nice

razteo said:
Here you go, 275 Falkens:

very nice!

DionR · Oct 4, 2017

I like it.

Were the WRTs original to the car, or added later?

razteo · Oct 4, 2017

DionR said:
I like it.

Were the WRT's original to the car, or added later?

They came with the car, with 245 Goodyears.

DionR · Oct 4, 2017

Did you buy it new like that? Or used?

Thanks!

razteo · Oct 4, 2017

Bought it like this new, this past weekend.
The rims are a factory option that I had to paid extra for.
It took me a while to find the right color and other options I wanted with this rims. But I think is worth it.

Tre_S"R/T"8 · Oct 4, 2017

tire size

with those 9 inch rims you can go 315 in the rear with no rubbing and good contact patch...but 275 is the largest for the front. I went with 275/40 all around...Conti Extreme Contact Sport....lovin' them...supper grippy.

Jimmy N. · Apr 18, 2019

Tre_S"R/T"8 said:
with those 9 inch rims you can go 315 in the rear with no rubbing and good contact patch...

I haven't looked up the approved rim widths for a 315, but wouldn't handling be kinda sketchy on a 9-inch rim, even if they are approved?

Shaun Grent · Apr 18, 2019

How is it driving now any rubbing issues or anything i order 275/40/20 and wheel are same as yours 20x9 factorys really need make sure no issue in rubbing please let me know!

A Guy · Apr 19, 2019

Minimum recommended for a 315/35 would be 10.5"

A Guy

Cuda340 · Apr 19, 2019

Here are three photos of my new Cooper Zeon RS3-G1 275/40-20 tires mounted on my 9" Alcoa forged aluminum wheels. They look and handle great on my SRT and were not that expensive.

JavierA · Apr 19, 2019

Cuda340 said:
Here are three photos of my new Cooper Zeon RS3-G1 275/40-20 tires mounted on my 9" Alcoa forged aluminum wheels. They look and handle great on my SRT and were not that expensive.

Looks great and thanks for the info a few months back. Will be installing my Zeon's in about another month. They have been in my garage for a few months since I still have some meat on my Atturo 800s. I got a bit over 30k miles on them and still have about 3/32 so can't complain about them but looking forward to a more performance tire.

EricG · Apr 19, 2019

^^^Those look pretty all-seasony, I hope they perform they way you want them to.

Cuda340 · Apr 19, 2019

The new Cooper Zeon RS3-G1 tire is an ultra high performance all-season tire. It got excellent reviews. Check out the thread that I started last year.

https://www.challengertalk.com/forums/f79/new-cooper-g1-tires-my-srt-647690/?647690=#post8237642

SethHaley · Aug 15, 2019

Reviving this thread- I have 2012 R/T with stock rims (20") and 245/45r 20's on now...want to go with different rims (20") and this time I want 275/40r20, how much wider will this make the tires? Do I need 10"rims?

razteo · Aug 15, 2019

I have the new body and it works perfect with the 20” factory rims – see my earlier pictures from 2017 before & after.
You have the older body – I’m not sure if the wheel clearances are the same. Check that first, and if so, you’re all set. IMO it shouldn’t be too far off, if at all..

Rys Black Beauty · Aug 26, 2019

When you get these new wider tires make sure you have your alignment checked.

Jimmy N. · Aug 26, 2019

Or, use the tape measure yourself. It's not hard to do.

Jimmy N. · Mar 4, 2020

One side each, to play it safe.

A Guy · Mar 4, 2020

With SRT center caps...

A Guy

Jimmy N. · Mar 4, 2020

What color?

Louie · Mar 31, 2021

Just ordered some toyos prox 275/45/20 for my 2020 Charger scatpack. Hopefully they’ll fit

Rys Black Beauty · Feb 19, 2025

315 minimum rim width is 10.5.

What about 275/45R20?

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