Changing Tire Aspect Ratio: The Effects - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Grayman · 10-16-2013, 09:05 PM

I've been looking at tire options lately for my car. I'm still running on the 245/45-20 front and 275/40-20 rear Pirellis on 8.5" and 9.5" wheels respectively.

Pretty much everything I'm interested in is lower profile than the stock tires. I'm wondering what the effects would be by going to a lower profile tire? Aside from the speedometer being off, I've read this can adversely affect the traction control. What exactly will I be getting into by changing to a smaller aspect ratio tire?

I've got 3-piece Forgeline wheels and have checked on having the fronts resized to match the rears.

Witchdoctor92 · 10-17-2013, 11:04 AM

If I understand correctly, the speedo will be off but as long as the tire heights are close to each other the TC will be OK.

So Cal Camaro · 10-17-2013, 12:55 PM

One thing to consider is your car may be lower if you run 30 or 35 series tires, when the outside diameter of the tires decrease, you will be lowering the ride height of your Camaro....sometimes very slight change but if more than a inch difference, your going lower by a 1/2 inch...

SSMickey · 10-17-2013, 02:28 PM

As long as the tire heights match, ABS and Stabilitrac will be fine. You can reprogram the new tire height in HP Tuners easily, but you going to lose your warranty as your essentially tuning the vehicle. If you do this, DO NOT use the tire height listed by the manufacturer. Install the new tires and wheels and measure the tire height with the car on the ground. You'll be more accurate. For example, the original tire height is listed as 28.7 but it is programed into the tune as 27.79.

2SS45th · 10-17-2013, 04:08 PM

As long as you go wider you can drop aspect ratio, and maintain the same diameter as stock.

Grayman · 10-17-2013, 09:52 PM

From what I'm reading it really doesn't sound like it's the smart move. I have a hard enough time getting in and out of the driveway. I don't really have any complaints about the PZero's, but I also don't like being so limited in performance tires.

10-16-2013, 09:05 PM	#1
Grayman Drives: 2012 SS Conv. w/ SLP ZL454 package Join Date: Jan 2013 Location: Tulsa, OK Posts: 14 View My Garage	Changing Tire Aspect Ratio: The Effects I've been looking at tire options lately for my car. I'm still running on the 245/45-20 front and 275/40-20 rear Pirellis on 8.5" and 9.5" wheels respectively. Pretty much everything I'm interested in is lower profile than the stock tires. I'm wondering what the effects would be by going to a lower profile tire? Aside from the speedometer being off, I've read this can adversely affect the traction control. What exactly will I be getting into by changing to a smaller aspect ratio tire? I've got 3-piece Forgeline wheels and have checked on having the fronts resized to match the rears.

10-17-2013, 11:04 AM	#2
Witchdoctor92 Drives: 2012 1SS Black with white rally str Join Date: Jul 2011 Location: Corpus Christi, TX Posts: 611	If I understand correctly, the speedo will be off but as long as the tire heights are close to each other the TC will be OK. __________________ It's good to be the King.

10-17-2013, 12:55 PM	#3
So Cal Camaro So Cal Race Team Drives: 2013 Camaro Join Date: Mar 2010 Location: Sunny So Cal Posts: 3,584	One thing to consider is your car may be lower if you run 30 or 35 series tires, when the outside diameter of the tires decrease, you will be lowering the ride height of your Camaro....sometimes very slight change but if more than a inch difference, your going lower by a 1/2 inch... __________________

10-17-2013, 02:28 PM	#4
SSMickey Drives: 2010 IBM 2SS Join Date: Feb 2010 Location: Columbia S.C. Posts: 1,455 View My Garage	As long as the tire heights match, ABS and Stabilitrac will be fine. You can reprogram the new tire height in HP Tuners easily, but you going to lose your warranty as your essentially tuning the vehicle. If you do this, DO NOT use the tire height listed by the manufacturer. Install the new tires and wheels and measure the tire height with the car on the ground. You'll be more accurate. For example, the original tire height is listed as 28.7 but it is programed into the tune as 27.79. __________________ ProCharger P1X, Vengeance Racing Kaotic Cam, ARH Headers and Exhaust with Borla ATAK mufflers, MGW Shifter, MTI Drop Springs, Forgeline RB3C Wheels, 3.91 gears, Night Owl LED Control System

10-17-2013, 04:08 PM	#5
2SS45th Drives: 11 Seconds or Faster Join Date: May 2012 Location: Arvada, Colorado Posts: 2,797 View My Garage	As long as you go wider you can drop aspect ratio, and maintain the same diameter as stock. __________________ I Ain't About That Stock Life.

10-17-2013, 09:52 PM	#6
Grayman Drives: 2012 SS Conv. w/ SLP ZL454 package Join Date: Jan 2013 Location: Tulsa, OK Posts: 14 View My Garage	From what I'm reading it really doesn't sound like it's the smart move. I have a hard enough time getting in and out of the driveway. I don't really have any complaints about the PZero's, but I also don't like being so limited in performance tires.