: 275s in the rear...



Luna.
12-11-06, 09:19 PM
I've seen several threads about this, but I wanted to pinpoint the discussion to this specific point:

Will 275s make a "significant" improvement related to traction over 255s?

I'm seriously considering putting 275s on the rear, as my traction problem is just frustrating, but there are some definite drawbacks to that.

Thoughts?

stkshkr
12-11-06, 09:40 PM
Size change as stated will not make a significant improvement there is only about 1.3 inches difference between 245's and 275's. The tire compound is the key to traction. I have GSD3 275's on the rear for the street but get much greater traction with 245 drag radials that have a very soft compound. It's always going to be a tradeoff for something, wet traction, cold weather, snow, road noise, wear, etc.

wildwhl
12-11-06, 09:42 PM
:yeah:

CTS-V420
12-11-06, 09:59 PM
if your goin from you runcraps to any new tire you will love it !

Luna.
12-11-06, 10:38 PM
I could care less about anything else at the moment, save for dry traction. :cool2:


:yeah:

Wait a minute. I thought you were one who was recommending the 275s in the rear! :D

heavymetals
12-11-06, 10:52 PM
If your going to change the rear only, then why not split the rims and really put something wide on?

Luna.
12-11-06, 11:00 PM
If your going to change the rear only, then why not split the rims and really put something wide on?

Perhaps I mis-spoke earlier.

I want the minimum required in order to at least mat the throttle in first gear. Drag racing, like at a track, doesn't interest me.

Clearly, no one is going to know what the minimum required would be, but 255s in the rear just isn't cutting it. As such, I was inquiring if 275s would make a significant difference, for I don't believe that 275s in the rear would have a significant, detrimental effect on handling.

heavymetals
12-11-06, 11:18 PM
I remembered that Law had his rims split and I think he put on 285s(?)

stkshkr
12-11-06, 11:50 PM
275's = no signficant difference, if size is the only change made.

trukk
12-12-06, 12:16 PM
275's = no signficant difference, if size is the only change made.

I'd have to mostly agree with this. I have 275's in back, for about 20k miles now. I do have a bit more traction but nothing to write home about. You also loose a bit in the balance/handling deptartment, but again nothing major.

Using the 8.5" rim, I'd have to say the 275 swap is a cosmetic mod. I don't see myself going back to 245's or 255's. The 275's just looks like it belongs, and is the way the car should look from the factory.

-Chris

Luna.
12-12-06, 01:09 PM
I remembered that Law had his rims split and I think he put on 285s(?)

That is a consideration, for I did like the look of his car with those tires. For crying out loud, I certainly hope that with 285s in the rear I'd be able to at least just mat the throttle in first gear! :D

For the street, has anyone put anything wider on the rear than 285s?

Thanks for your thoughts as well Trukk. That's what I would expect.

heavymetals
12-12-06, 01:51 PM
old link info:

http://www.cadillacforums.com/forums/cadillac-cts-v-series-forum/72805-dont-bother-putting-275s-rears-your.html?highlight=split+rims

trekster
12-12-06, 02:48 PM
I also have 275s on the rear no improvement. Maybe the traction is a bit better.
Don't bother since you won't be able to rotate your tires. I like the wide look of the rear though.

heavymetals
12-12-06, 03:48 PM
From what I could find searching the forum, looks like wide rear tires get into the realm of rubbing on the fenders :( over a certain size. :banghead:

Want to roll the fender wells? :jawdrop:

AmesCTS-V
12-12-06, 06:22 PM
275's are great. I like them. No rubbing either.

1QUICKV
12-12-06, 08:42 PM
275 is how tall the tire is, I think. And the second number is how wide. the smaller the number the wider the tire (45). 275 would just make the gearing different. I think this is the case.... but i must be wrong if all you guys are thinking the same way.

heavymetals
12-12-06, 08:57 PM
275 is how tall the tire is, I think. And the second number is how wide. the smaller the number the wider the tire (45). 275 would just make the gearing different. I think this is the case.... but i must be wrong if all you guys are thinking the same way.


Tire info: http://www.rma.org/tire_safety/tire_maintenance_and_safety/how_to_take_care_of_your_tires/sidewall_story.cfm

AmesCTS-V
12-13-06, 01:43 AM
275 is how tall the tire is, I think. And the second number is how wide. the smaller the number the wider the tire (45). 275 would just make the gearing different. I think this is the case.... but i must be wrong if all you guys are thinking the same way.

That's not the case 275 is the width. It's Width/Size/Diameter

There are a ton of size calculators, but I wrote my own anyway:) You can use it to convert the 275 to size in inches.

http://www.blackcts-v.com/TireSizing.aspx

wildwhl
12-13-06, 02:54 AM
Luna -

I do recommend 275's - but not on stock width wheels.

WW

Luna.
12-13-06, 01:55 PM
Perhaps I missed it, but what is the max amount that the stock rim can be widened? If I understand correctly, 9" isn't too big a deal, but can one take it to 9.5" Larger?

I think I'm with Heavy on this one. Fit the biggest damn tires in the rear one can get (within reason, of course). I'd love to get 285s or 295s in the rear on the recommended sized rim(s).

atdeneve
12-13-06, 02:26 PM
I think Wildwhl has 9.25 and I was almost certain someone had 9.5s, though I could be mistaken. Almost certain, though, that anything larger than that you're lookin at gettin some longer rotor/wheel studs.

I also was looking to have one set of my stocks widened out back. Just need to find out who can do the job and do it well. Not something I want fcuked up.

So, how's about it? Can we do 9.5 out back without the need for longer studs? And for those on the east coast, who do we talk to to get it done?