I have never heard of any problems and am wondering if anyone has had or heard of any problems with running different sizes on the front and rear. I would think it would be close enough but a customer had a concern about running a 17 and 18 inch combo affecting either traction control or the ABS.

Thanks
Tom.

 

The issue comes up when the tire overall diameter is excessive.

So the if the front were 17" x 9.5" with a 275/40ZR17 tire and the rear was 18" x9.5" witha 275/35ZR18 tire. All is good in the world.

 

As long as tire diameters are close, shouldn't be an issue. I'm running 275/40/17 (25.7 OD) in the front and 295/35/18 (26.1 OD) in the back without problems.

 

i know my bud is running the 17x9.5 and 18x9.5 z06 setup, i dont know what size tires he is running, but his ABS light will sometimes come on when he's on the highway

 

Could you run 275/40/17 in the front and 285/40/17 in the back? or is that too much of a height difference?

 

I believe you want to stay within a 3% difference and everything should be fine.
It also depends on the tire itself, manufacturers tend to measure a tad differently which is why some may run smaller/bigger or narrower/wider in the same size

 

Good evening Tom.

What many folks overlook is the fact that when the overall tire diameter is not equal (oem) diameter, ABS will not operate as it was intended.

There is going to be a tolerance that it will still function BUT the feedback the ABS computer is sensing may not result in proper function and control. Case in point, your ABS system activates when it wasn't necessary actually hampering performance...or not functioning correctly at all.

ABS tends to be more problematic then helpful in most applications that we see on these boards. Most folks modify the cars quite a bit... trying to work around ABS can be quite a hassle. Just troubleshooting it can get quite expensive. If you could tune ABS, that would be fantastic! You cannot!

This may be a bit off-topic to your initial question but we do have a solution. You may recommend our kits to your customers. Instead of concentrating on ABS or not purchasing a wheel setup that they really want…our ABS delete kits are a cost effective solution. Actually giving MORE control to the end user. The ability to fine tune their brake bias through the use of the proportioning valves included with all our kits is a very nice feature. Removing ABS drops quite a bit of weight from the engine bay, increases air flow, decreases problematic issues with tire/wheel combo’s or an inoperable ABS system. There really are only benefits that will be seen.

Some members may be confused and worry that if ABS is removed, normal braking is hampered…that is furthest from the truth! The ONLY time ABS is used is when you feel the brakes modulate. With the stock setup, you are at the mercy of the ABS system to sense when it needs modulated. Don’t misunderstand me…A stock OEM setup is fine. Modify the braking system, wheel combo or tire package…your computer has no idea that you’ve made these changes and still operates under the assumption all is OEM…there is no learning curve or closed loop.

 

so what happens if you slam on the brakes? do all of the tires lock up or what?

 

i run 275 40 17 and 315 35 17 i feel no diff in normal driving I've never slammed on my brakes