Mixing tire brands?

[Brent 930]

For example; could you run a set of tires up front with a 220 rating while running a set of rear tires with also a 220 rating but a different brand? I'm pretty sure you don't want to mix tire wear ratings or run two different brands either front and back.

Thanks,

Brent

[tshih]

It is never a good idea to run different make tires on the same car especially a Porsche whose handling and safety has been tested ad nauseum to specify what is approved brands of tires with N1, N2, etc ratings. different tires will be actually dangerous since the car's handling will be grossly compromised and driving in control as well as fast means having a great understanding of the balance between the 4 wheels and the grip of each at any moment.

[A Quiet Boom]

Take it from me, DON'T DO IT! I nearly wrecked my car weeks after owning it when I put different brands front and rear and I'm used to mixed tires from my drag-racing days (skinnies in front and slicks in rear) The car also behaved badly on the freeway. I switched to the same brand all around and the car has been great ever since.

[Brent 930]

Thanks, what are N1 and N2 ratings?

Brent

[vash]

i havent done it, but i know some folks that have. they feel that the 911 is so damn different from the front to rear, for example, weight, tire widths, regular shocks in front, sports in back, etc, that you will not tell the difference. like i said, i havent tried it.

[Zeke]

Brent, what did you have in mind? That's a pretty big question if you consider all the tires made today.

Personally, I like the tires to match just so they match. There was a time in my life when I didn't have enough money to be that vain. If I had to run different brands, I would run the same type, i.e., dry summer performance or wets. Similar tread patterns and wear ratings. You know, a little common sense. It won't be a major crime.

If you experience any problems; the car seems a bit funny, get on to something else. Don't push it. You will most likely find the most negatives on mismatched tires on wet roads. Different traction factors.

[braddb_82SC]

I've mixed tires several times on my 'SC with no ill effects. When I bought the car used in '94 it came with Dunlop SP8000's on the front and DM40's (I think?) on the back. Due the their varying wear rates I have typically replaced two sets of rears for each set of fronts. The 40/60 weight ratio of the 911 makes matching tire wear ratings front to back irrelevant. When I have bought rears independently I have not paid much head to matching the front tire brand/type.
I just recently ordered new tires and made an exception. My current fronts have lots of tread remaining but I am replacing them along with the rears because I dislike the Kuhmo's. The four I have on order from Tirerack are Yoko ES100's.

-Brad

[tshih]

N1 and N2 specifications are the OEM approved tires given by Porsche after having done extensive testing for approved use on the Nurburgring (they have a special group that does tire testing for all conditions and come up with the ones that works best (noise, wear, performance, predictability at limits, transitional characteristics, etc. That's what the costs of buying a Porsche buys you-testing and development. Look at the Tirerack ads and you'll see the N1, N2, etc ratings in superscripts on some brand name tires like Michelin Pilots, Bridgestone S02 or 03, etc. Kuhmos are not one of those with the tested approval but are not bad for the price and ratings (speed).

[Zeke]

Originally posted by braddb_82SC
The 40/60 weight ratio of the 911 makes matching tire wear ratings front to back irrelevant. -Brad

Except in terms of traction. And tread wear is all we have to indicate traction. I don't think you want softs on the rear and hards on the front. Or, maybe you do.

I correct myself: UTOG rates traction, temp resistance and wear. I think, however, they are closely related.

[Dantilla]

You're probably okay for a Starbuck's run. You will not pass a tech inspection for any track time.

[tshih]

Go ahead and stick harder fronts versus softer rears and you have a 928 type of understeering handling 911. Not to mention it defeats all the work the engineers have put into testing the handling of the torsion bars and shocks with the OEM type tires. As the tires wear unevenly still due to the new parameters you've introduce you can learn how the car's character changes with each drive and never know the limits of the moment. Makes life with the car very interesting indeed.

[Brent 930]

Zeke, I'm a poor man with a rich mans car so money is a concern. BUT, I'm living a dream and have no regrets that my car has made me broke.

Thanks tshih, I have seen that at the tirerack now that you mentioned it.

[Jim2]

Brent 930, I assume you are driving a 930. On the track I have run different R compound brands on the front versus rear of my old 930 and have never experienced any strange dynamics. To my surprise, even with odd combinations my car has been competitive, producing somewhat consistent lap times with alike tire sets. However, I don't think I would endorse dramatic variations for the street. I recall a rutted portion of asphalt taking me by surprise once, and I could imagine if this were compounded in any way while making a panic maneuver.

[Wil Ferch]

Something to ponder as you wrsestle this question....

The 220 ( or whatever) wear ratings are not measured against an independent standard. Meaning? They have absolutely NO relevance as a comparison tool from one brand name to another. NONE. Each manufactuer takes one of their tires....assigns a 100 number for it. Then, as they compare another tire FROM THE SAME MANUFACTURER...if it wears out half as fast...they assign it a number of 200.

And so on.

You can't compare the numbers...not even roughly....across brand names.

----Wil

[thabaer]

Even if wear rates were uniformly given by all manufacturers, different compounds with the same wear rate from a single maker could still have different levels of grip, even different years of the exact same tire model. Going through two sets of rears per one set of fronts forces many of us to at least put on fresh rears with 1/2 worn fronts of the same tire, and most of us don't notice any problems after breaking them in. If you can get some quantitative data that includes how they behave cold/hot,wet/dry, etc... then you shouldn't be pushing your luck beyond reasonable limits by mixing tires. Just keep in mind that you ARE running with the mismatch and the more the nature of the two differ the more likely they are to be unpredictable.

I mixed rear D40s w/ P700s when I switched from the Pirellis, my car was fine with that combination and I always drive it like I stole it. As always, that's with MY car and somebody else with the same model and year might see different results due to suspension, weight of options, etc...

[3.2 CAB]

I have TOYO on the front and YOKO on the rear, have not had any type of problems. Handles like it is on rails. They are both, premium, high $peed rated tires, I do not know what the lower end tires would be like though.

[Brent 930]

I think if you knew 2 different brand tires were approx. equal and for wet traction it should be OK. Rain would be the bigger deal but also if you had 2 totally different tractions. Since I don't think I will ever know I will stick with the same tires all around.

[Ray B]

Wil is, once again, correct. Temp, treadwear, etc. are brand specific. I see no problem with mixing if the tires are similar. Mixing R compound with street tires might get a bit sporty.

[arerrac]

I have Toyo Proxes FZ4's (all season high performance) on my Carrera. The rears wore out and I need to replace, but they have been discontinued and replaced by the new Proxes 4(all season ULTRA-high performance). Very simulat tread. Only difference is traction is now up to AA. I am still breaking them in (tread squirm), but have experienced no ill effects. But I will get new MATCHING fronts once it starts to rain.
-W