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YOUR RESEARCHMixing Tires - Michelin PS N2 front P3 rear
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Run bridgestone grand touring all-season 225/45rf18
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On my track car I run a Bridgestone Grand Touring All-Season 225/45RF18 on the Right Front and a Bridgestone Potenza RE 050 225/40-R18 88Y on the Left Front.
Leading evidence: 'Run bridgestone grand touring all-season 225/45rf18' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'tire dealers or people' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Adjust handling' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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On the rear I run Toyo Proxes 1 295/35 ZR18 on the Left and Toyo Proxes 1 295/30 ZR 18 on the Right.
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Suggestion
There is only so far you can go with adjusting tire pressure to adjust handling.
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Suggestion
There is only so far you can go with adjusting tire pressure to adjust handling.
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The ones that tell you that all four have to be the same are probably the tire dealers or people that don't use common sense.
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Suggestion
Tire pressure would not be my first choice in compensating for compound changes, side wall structure or age of the tires when mixing and matching tires front and rear.
Run bridgestone grand touring all-season 225/45rf18
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On my track car I run a Bridgestone Grand Touring All-Season 225/45RF18 on the Right Front and a Bridgestone Potenza RE 050 225/40-R18 88Y on the Left Front.
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So I got a rear flat and the tire is not salvageable. The rears probably had 1K left anyway. I've got discontinued Michelin Pilot Sport N2 in front. Any concern with putting P3's on the back?
Only street driving at this point, local twisties and on ramps are is hard as she's driven. I don't think it should be an issue but thought I'd solicit some feedback.
What they said. Side to side is a different matter but axle to axle should be OK, especially since the new ones will be at the back so less chance of unintended oversteer.
Aw man, I thought I heard or read somewhere you should try to keep the tires consistent from front to back. I would've definitely bought cheaper tires. Oh well, next time.
Is your's a C2 or 4? I would think it would be more of an issue with different grip levels on the C4, but still - I would think you'll be fine.
I have a C4, and run a softer rear vs. front. Been working great.
Think for a second, the car weighs different from front to back so even if you had the same tires, grip will be different so using different tires is not a problem. The ones that tell you that all four have to be the same are probably the tire dealers or people that don't use common sense.
If your car has the PSM option I recommend that you put the same tires both front and rear because of the way stability controls are tuned. Since the Michelin PS2 N3 are the original fitment, they have been tuned specially for the car and will give you the perfect balance and chassis tune that Porsche was looking for. Would you feel the difference? Not on the street but on spirited driving or track yes, especially in terms of progressivity of the car at the limit of adherence. Using 2 different sets will have the car go from understeer to oversteer differently and more suddenly. Just went from 4 continental all season DWS to 4 PS2 N3 and difference is quite noticeable (of course summer tires like the PS2 always offer more grip than A/S). I love them, good to live in the South!
Sports car manufacturers set their cars up with understeer from the factory because it's safer, not better. To get balance at the track, the first thing you do is try and dial out the understeer. And as far as the PSM being effected by using a different rear tire model I'm not buying it.
And as for going from an all season tire to a summer performance tire, yes, it should be remarkably better. But if you like the PS2, you would have loved the Pilot Super Sports. They are less expensive and a much better tire.
Totally agree on the Pilot Super Sport being a great tire but I cannot get the fitment for the rear tire on my 996 MK2 (285/30 R18) the 265/35 R18 is available for MK1. I wanted to stick to the OEM fitment.
Think for a minute different size tires & psi spec front & rear also. Minimizing excessive oversteer is easier with superior traction tires on the rear.
If you drive your car the way you ride your bike in your avatar, I'd be very careful about mixing tires. Especially in rainy conditions. Just pooping around town in stop and go traffic won't be a concern, but threshold braking, high g loads, any driving that is at the edge needs a balanced set up and that includes all four tires. IMO.
You can balance the front/rear using air pressure. If the car understeers, either more air in the rear or less in the front. If it oversteers, the other way around. Yah screw the recommended pressures. I'm talking a couple of psi not huge amounts.
As I said...pooping around town I don't think it would be an issue...but in wet weather or under 9 and 10 tenths driving, I would not be comfortable with different tires front and rear. I base that on what Porsche says, on conversations with tire people, on conversations with drivers who have a lot of track time, and on what seems to me to be common sense. Whether or not you agree with me has nothing to do with it.
Tire pressure would not be my first choice in compensating for compound changes, side wall structure or age of the tires when mixing and matching tires front and rear. Just my opinion.
For any type of street driving that doesn't risk hitting curbs or looking like a total ***, you will not notice a difference in brands between front and rear. If you are pushing your car on the track to the point where you can tell the difference, it's time to upgrade to a set of track tires anyway.
Can't provide you with any real world experience as I have never done what you are contemplating.
And with no real authority frankly neither can anyone else unless they have done what you are seeking to do, done using the same tires mis-matching.
All I can offer is Porsche specifically cautions against what you are wanting to do.
If you elect to ignore this then you are on your own.
Now the car may be ok. I have no idea how sensitive it is to the differences in tires. As I said above Porsche cautions against this as no way it can test all combinations and understandably Porsche has to err on the side of caution. (Consider what Porsche faced from the aftermath of that horrible Carrera GT accident in which the car was on tires sanctioned by Porsche.)
If you go ahead report back your impressions/experiences.
I don't drive anywhere near the limit on the street and I'm not quite ready to track her yet, to many other priorities. So I'm pretty sure I'll be safe. I just wanted to rule out any kind of overt unruly behavior. Thanks everyone. Not sure that it matters with conservative driving, but the car is a C2.
I don't know about other clubs, but my PCA region will not allow mixed tires (even from same manufacturer) for DE events, just as FYI.
My car had two different BS models front to rear when I got it. I had zero issues and lived to tell the story. Since have go to matched set, but still a bit rebellious with non "N" rating
If you have an AWD car that does any kind of fancy torque-vectoring... then you definiitely need 4 identical tires. Otherwise, for 2WD driving at normal street speeds, you can mix/match at the axle-level and should be okay. OP should be fine, can match up the fronts when the wear down or one blows...
I almost didn't buy my car because the PO had two different tires on the rear. The first thing I sought out to do to my car after purchase was to match the rears. Due to the staggered front-rear size differences and what was available, I ended up putting on a full set of Continental Procontact tires on all four.
My other car is an '05 Acura RL and it has that Honda SH-AWD system which puts advance rotation and more tourque to the outside rear tire, and if you drive one of these cars with mismatched tires you can really feel the system fighting itself, even in a straight line at normal speeds.
It will be just fine.
On my track car I run a Bridgestone Grand Touring All-Season 225/45RF18 on the Right Front and a Bridgestone Potenza RE 050 225/40-R18 88Y on the Left Front. On the rear I run Toyo Proxes 1 295/35 ZR18 on the Left and Toyo Proxes 1 295/30 ZR 18 on the Right.
That is called "Stagger" all of the NASCAR teams do something like that, and they go real fast too. I have to say with this setup my car is only half fast but it staggers around corners too, just like them NASCAR race cars!!
Nascar is set up to make oval-track, banking turns which are always in the same direction. And when they do go on a road racing track I'll bet you they have a completly different setup that involves same tire diameters on each axle. "Stagger" is different size front vs. rear.
I can't think of a single reason why anyone would you ever want to put mismatched rubber and mismatched diameter tires on the same axle for a road racing car?
Just noticed the smilies at the end.... so I'm thinking my sarcasm detector must have dead batteries again???
The only way to know if there is any unruly behavior is to fit the tires and spend some time in the car on the road.
I have read reports of some owners venturing off the reservation with regards to tires having nothing but glowing results. Others not so much.
So if you want proceed then fit the tires and try the car. If no problem well there you are.
If a problem easy enough to address the problem: Have the "right" tires fitted.
Then your only problem is you have some tires you can use but maybe can sell to recoup some of their cost.
Uh, generally, less air pressure = more grip. Of course that is up to a point. The point where the tires are under-inflated and you are running on the edges of the tires.
If you have understeer, you need more grip in the front. Oversteer more grip in the back. So to reduce understeer, either lower front pressure, or increase rear, or a combination of both. In any case, just change 1 psi at a time.
There is only so far you can go with adjusting tire pressure to adjust handling.
What you really need to decrease understeer is front camber which increases grip and you ain't going to get much with the stock suspension.
To increase camber you can in order of increasing cost:
1 lower the car (that will get you maybe .5 deg
2 add camber plates (that will get you around 1 deg)
3 add GT3 adjustable control arms (that will gate you 1-3 deg)
I went to M030 ROW springs/struts and camber plates and went from .9 to 2.2 camber. The ROW springs lower the car around 20 mm
A really good performance alignment also helps a lot
