: Largest tires I can put on the 2009 CTS V....



csp3000
11-30-09, 02:01 PM
I have a set of 20x9.5 inch wheels for the front and a set of 20x10.5 inch wheels for the rear being built right now for the V. What is the largest or best tire size I can run with these wheels for the 09 V.

wfo
11-30-09, 06:04 PM
Sounds nice..which wheels?

Tire Rack typically has the up to the minute info on tire/wheel configs for our rides. Also compare this info with what the wheel maker is telling you.

csp3000
12-02-09, 11:33 AM
:bump:

musclesbmf
12-02-09, 02:54 PM
I have 285's on my 20 x 10.5 rims and like that size a lot. Fits and looks perfect.

Mark

Fantasy Toys
12-02-09, 10:50 PM
I usually use 255/35 20 up front & 285/30 20 out back for that size combo

Ross Racing
12-02-09, 11:58 PM
my 255/35/20 & 295/30/20 Toyo P4 fits absolutly perfect

csp3000
12-03-09, 11:32 AM
Sounds nice..which wheels?

Tire Rack typically has the up to the minute info on tire/wheel configs for our rides. Also compare this info with what the wheel maker is telling you.

Thanks for the help wfo!

The wheels I am going with are Nutek 515's. The persons who owns this company is named Gene Howald and he is the person who started HRE Wheels. If you have a sec go to the website at www.nutekwheels.com. The finish I am doing is a powder coated black background on the center with a brushed spoke face. The inner rim will be powder coated black and chrome outer lip.

csp3000
12-03-09, 11:36 AM
I usually use 255/35 20 up front & 285/30 20 out back for that size combo


my 255/35/20 & 295/30/20 Toyo P4 fits absolutly perfect


Thanks guys...!

Do you think I could get a 305/30/20 on the rears and 265/35/20 on the front with out any problems?

demorgan59
12-03-09, 11:45 AM
I don't think 305's on 10 1/2" wheels will fit on the rear without spacing them to the outside at least 1/4". You would need extended studs to do this however. Also, the stock offset is "pushed out" as far as I think would look proper. I believe that the lower control arm is the limiting factor for inside clearance.

csp3000
12-03-09, 01:13 PM
I don't think 305's on 10 1/2" wheels will fit on the rear without spacing them to the outside at least 1/4". You would need extended studs to do this however. Also, the stock offset is "pushed out" as far as I think would look proper. I believe that the lower control arm is the limiting factor for inside clearance.

Do you think I can get away with 265's for the front?

Baxman
12-03-09, 09:39 PM
This online calculator won't help with actual fitment issues, but is helpful with speedo error and calibration.

http://www.miata.net/garage/tirecalc.html

danothemano
12-04-09, 09:15 PM
The more tire on the ground the better especially with this car. You could easily put 295/35s on the fronts and 325/30s on the rears. I have 265/35s and 295/30s on my car with the stock rims right now.

Fastlane 09 CTS-V
12-06-09, 09:56 PM
I also have 325/30's on stock rims on the rear. They work well for drag racing, but not very goog for handling. Sidewalls bulge too much.

verbs
12-08-09, 02:28 AM
I also have 325/30's on stock rims on the rear. They work well for drag racing

Yeah, I'm going to say you're wrong on this one.

1. With only a 9.5" rim in the rear, you're really not going to get much more if any contact patch on a 325mm tire on a stock rim than you would with the stock 285mm tire on a stock rim.

2. Sidewall is just as important for traction as width, and you lost sidewall over the stock tires/rims with your combo.

3. Your new tire combination is heavier than the stock setup, increasing your rotating mass, and likely slowing your car down accelerationwise.

I doubt you gained anything from your new setup.

ericpd
12-08-09, 09:52 AM
Yeah, I'm going to say you're wrong on this one.

1. With only a 9.5" rim in the rear, you're really not going to get much more if any contact patch on a 325mm tire on a stock rim than you would with the stock 285mm tire on a stock rim.

2. Sidewall is just as important for traction as width, and you lost sidewall over the stock tires/rims with your combo.

3. Your new tire combination is heavier than the stock setup, increasing your rotating mass, and likely slowing your car down accelerationwise.

I doubt you gained anything from your new setup.

School's in,... the learning has begun! I think.

Luna.
12-08-09, 11:19 PM
Yeah, I'm going to say you're wrong on this one.

1. With only a 9.5" rim in the rear, you're really not going to get much more if any contact patch on a 325mm tire on a stock rim than you would with the stock 285mm tire on a stock rim.

2. Sidewall is just as important for traction as width, and you lost sidewall over the stock tires/rims with your combo.

3. Your new tire combination is heavier than the stock setup, increasing your rotating mass, and likely slowing your car down accelerationwise.

I doubt you gained anything from your new setup.

I tend to agree. We beat the pi$$ out of this concept on the V1 forum...

komar
12-10-09, 06:49 PM
he ran a 10.x on that tire. id say it works for him...

komar
12-10-09, 07:01 PM
Toyo proxy4 255/35/20, 295/30/20
Toyo T1R 255/35/20, 305/30/20

Not sure if the T1R will fit/look right on the rear, but i'm taking the chance when it's time. unless it's proven ill attempt.

Anyone have pics of sizes above on their V?

verbs
12-14-09, 05:26 AM
he ran a 10.x on that tire. id say it works for him...:nono: Just because he ran a good time doesn't mean they're the right size.

Nice example. :yawn:

Usain Bolt, the fastest man in the world could run a 100 yard dash in 10.x seconds wearing a size 18 shoe. Just because he'd still be faster than 99.9% of everyone else out there doesn't mean that's the best shoe. He can run a 9.69 in the right size, a 13. ;)

komar
12-14-09, 02:11 PM
:nono: Just because he ran a good time doesn't mean they're the right size.

Nice example. :yawn:

Usain Bolt, the fastest man in the world could run a 100 yard dash in 10.x seconds wearing a size 18 shoe. Just because he'd still be faster than 99.9% of everyone else out there doesn't mean that's the best shoe. He can run a 9.69 in the right size, a 13. ;)

i agree, just cause it works doesn't mean it's right. All i was saying is that it worked for him. when i first heard the size or 325, i though that better be a widened rim. I'm sure the contact patch is not maximized at all, but you take the car to a drag strip lower the air pressure enough and it works...

I think a 295 or 305 is about the largest size to fit on a OEM rim without sacrificing too much.

Fastlane 09 CTS-V
12-14-09, 09:13 PM
Like I said, I did it for a drag race. There about 12" of tire on the ground with the 325's. 1.60 sixty ft time. Not bad for a true radial.