Mixing Tire Brands Front To Rear
 

Hi,
Looking at running all season tires next winter on my 2019 ZL1.
Basically used for cold temps, dry weather cruising.
I found sizes that I think would work. Although different brands on the front and rear.
Fronts would be stock size 285/30/20.
Rear would be 295/30/20. These sizes are very close to stock diameter ratios.
I know doing this is not recommend.
Can someone please explain why.
Thanks,
Tyrolblue67

I ran a 285/35 and 275/35 Frt/Rr in an A/S tire, maybe consider those sizes. I used the BFG Comp2 A/S with no problems at all on the OE 1LE wheels. You have a little more option to depart in sizes from OE. Trying to get in these widths on a 30 profile is difficult on an A/S, but 35 series has a few more possibilities. In those sizes too I saw no deviation on the speedo. It was no more than 1mph off from stock speedo calibration.


I couldn't say why you don't mix manuf it's just a "rule". Especially on one axle.

I’m running PS4S in the front and R888Rs in the rear and love the set up.

Thanks for the responses guys.
It seems interesting these days as the experts "advise" not to mix brands front to rear.
Back in the day (1990's), I ran drag radials on the rear of my 1967 GTO and a different brand of street radial on the front. On many occasions, I drag raced the car then drove 2 hours home from the track on the expressway. Did cruise nights and drove around town with this set-up. Put many miles on the car without any issues.
Just wondering if there is some sort of an explanation as to why the experts "advise" not to do it. Especially while running the same category (all season) tires.
Thanks again,
Tyrolblue67

Tire manufactures warn that using tires with different performance characteristics or sizes can cause the vehicle's handling to become unbalanced, especially in bad weather or during emergency maneuvers.

If you can't match all four tires then the recommendation is to match in pairs front and back with tires that have similar construction, speed ratings, and traction characteristics.

Another option might be to save the ZL1 wheel/tires for summer driving. Pick up a set of new or used SS spec wheels and buy all-season or winter tires for the colder months.

The short answer is likely along the lines of different tires use different rubber compounds and constructions, even in the same category, which have an unknown and potentially detrimental impact to how the vehicle functions.

From a vehicle handling and performance aspect, all tires have different performance properties. Dry traction, wet traction, sensitivity to alignments, lat force generated vs. vertical load and slip angle, etc. Having mismatched properties like that can cause the car to perform poorly or even dangerously depending on the use conditions.

From a controls perspective, cars now have systems like ABS, traction control, and stability control that are specifically calibrated to be optimized for the specific OE tire. The further you stray from the OE tire the more you have a risk of these systems not being able to control the vehicle as well, and mismatching tires only makes these control systems worse on top of that from differing properties as mentioned above.

Different tires across one axle is specifically no-no because even if they're listed as the same size they might not be. Different diameter tires on one axle like that can cause driveline damage, uneven braking performance, and a bunch of other issues.

Now, I know all of that seems a bit dramatic, but keep in mind that's more of a worse case scenario thing. 9 times out of 10 you'll probably be OK having mismatched tires front to rear, it just won't be as nicely optimized/balanced as OE or if it's at least the same tire all around. But, since there is that ever-so-slight risk of causing an issue with vehicle control, it'd be irresponsible for an expert to advocate it without fully testing it to make sure it's safe which isn't worth the cost or time to do.

not sure why people do this...

Great explanation Alpha1BC.
That make sense.
Thanks for your input.
Regards,
Tyrolblue67

With a grain of salt those manuf or the industry saying not to do it are the ones that are selling tires so there's not a total unbiased opinion

With different sizes (285 vs 305 or 255 vs 275) front to rear, and the rear tires under power, it makes a hell of a lot less sense to "match" the front and rear with the same tire/manufacturer. This doesn't mean that you don't want to match the type of tire and general tread compound, but this isn't a square AWD car either. If possible, sure, match the tires, but maybe you want a little better front or rear traction? You can't rotate the rear tires to the front anyway and if you are hard on the throttle, you are going to burn down the rear tires faster anyway.

Again, some tires will be radically far apart, but many top performing tires are pretty close and you can just as easily optimize your setup by mis-matching front and rear, vs. going with the same all around.

And all that said, I wouldn't go out of my way to do it, unless there were extraordinary circumstances or I was looking to maximize some certain performance parameter.