What about 275/45R20? - Dodge Challenger Forum: Challenger & SRT8 Forums
2015 to Current R/T & RT Plus Specific This area is for vehicle specific information about the 2015 and beyond R/T and the R/T Plus

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 21 (permalink) Old 10-01-2017, 10:48 PM Thread Starter
Member
 
razteo's Avatar
 
Join Date: Oct 2017
Location: SoCal
Posts: 33
Thanks: 34
Thanked 8 Times in 6 Posts
Feedback Score: 0 reviews
(Thread Starter)
What about 275/45R20?

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.
Attached Thumbnails
Click image for larger version

Name:	IMG_9085.jpg
Views:	243
Size:	754.8 KB
ID:	849161  
razteo is offline  
The Following User Says Thank You to razteo For This Useful Post:
Beachlovers2 (10-02-2017)
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old 10-02-2017, 04:53 AM
Super Moderator
 
Cuda340's Avatar
 
Join Date: Sep 2006
Location: southern New Jersey
Posts: 13,086
Thanks: 12
Thanked 2,726 Times in 1,868 Posts
Garage
Feedback Score: 0 reviews
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-...ismetric=False


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Cuda340 is offline  
The Following 4 Users Say Thank You to Cuda340 For This Useful Post:
Mopar Ernie (10-03-2017), razteo (10-02-2017), RWL11 (10-02-2017), TwistedT (10-02-2017)
post #3 of 21 (permalink) Old 10-02-2017, 09:01 AM
Senior Member
 
Join Date: Oct 2009
Location: Wasilla, Alaska
Posts: 1,961
Thanks: 283
Thanked 337 Times in 255 Posts
Feedback Score: 0 reviews
Fitment is not an issue. When I went the 270 route there were a lot more choices in the 40 then 45 series locally.

2012 SRT automatic, PB 12.0490 with MT drag radials and trinity 93 octane tune.
maguson supercharger 5.5psi, forged piston/rods, Hellcat injectors, 10/1 compression, tuned for 90 octane. [email protected]
John Matthews is offline  
The Following User Says Thank You to John Matthews For This Useful Post:
razteo (10-02-2017)
Sponsored Links
Advertisement
 
post #4 of 21 (permalink) Old 10-02-2017, 10:18 AM
Senior Member
 
chris1992's Avatar
 
Join Date: Nov 2008
Location: Pineville, LA
Posts: 2,990
Thanks: 29
Thanked 195 Times in 139 Posts
Feedback Score: 1 reviews
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)

2015 Dodge Viper SRT
Stock

2009 Dodge Challenger R/T A5
SRT8 Brembos, JBA shorties, JBA catless mids, 3" MBRP catback, k&n drop-in filter (with the stock box), 3200 FTI TC, MTCM, blue tops, 275/40/17 M&H Racemasters, and tuned by [email protected] - 1/4 mile PB [email protected]
chris1992 is offline  
The Following User Says Thank You to chris1992 For This Useful Post:
razteo (10-02-2017)
post #5 of 21 (permalink) Old 10-02-2017, 10:53 AM Thread Starter
Member
 
razteo's Avatar
 
Join Date: Oct 2017
Location: SoCal
Posts: 33
Thanks: 34
Thanked 8 Times in 6 Posts
Feedback Score: 0 reviews
(Thread Starter)
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.?
razteo is offline  
post #6 of 21 (permalink) Old 10-02-2017, 01:08 PM
Junior Member
 
Join Date: Aug 2014
Location: Ruther Glen, VA
Posts: 19
Thanks: 0
Thanked 2 Times in 2 Posts
Feedback Score: 0 reviews
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
Knukey is offline  
The Following User Says Thank You to Knukey For This Useful Post:
razteo (10-03-2017)
post #7 of 21 (permalink) Old 10-03-2017, 01:28 PM Thread Starter
Member
 
razteo's Avatar
 
Join Date: Oct 2017
Location: SoCal
Posts: 33
Thanks: 34
Thanked 8 Times in 6 Posts
Feedback Score: 0 reviews
(Thread Starter)
Thank you.
The R/T is at the shop as we speak and 275 Falkens are been installed.
Can't wait!
razteo is offline  
post #8 of 21 (permalink) Old 10-03-2017, 01:33 PM
Junior Member
 
Join Date: Aug 2014
Location: Ruther Glen, VA
Posts: 19
Thanks: 0
Thanked 2 Times in 2 Posts
Feedback Score: 0 reviews
Post a pic.
Knukey is offline  
post #9 of 21 (permalink) Old 10-04-2017, 09:35 AM Thread Starter
Member
 
razteo's Avatar
 
Join Date: Oct 2017
Location: SoCal
Posts: 33
Thanks: 34
Thanked 8 Times in 6 Posts
Feedback Score: 0 reviews
(Thread Starter)
Here you go, 275 Falkens:




razteo is offline  
post #10 of 21 (permalink) Old 10-04-2017, 11:02 AM
Junior Member
 
Join Date: Sep 2016
Location: Spokane, WA
Posts: 24
Thanks: 15
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I like it.

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

'15 R/T 6M, Billet Silver, STP and no other options.

'74 Duster 360 4 Speed, original E58/D21 car.
DionR is offline  
Sponsored Links
Advertisement
 
Reply

  Dodge Challenger Forum: Challenger & SRT8 Forums > Model Specific Discussion > Dodge Challenger R/T Specific > 2015 to Current R/T & RT Plus Specific

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Challenger Forum: Challenger & SRT8 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome