Wheels too big?
Discussion
I am new to Porsche ownership and own a 2014 Boxster which is on the 20 inch rims and p zero rubber. The front wheels feel as though they are skipping on full lock at very low speed. Once up to any speed the car runs absolutely true.
Is this normal firstly, and would it be sensible to go back to 18 inch wheels? And is this a straightforward undertaking?
Any advice gratefully received.
Is this normal firstly, and would it be sensible to go back to 18 inch wheels? And is this a straightforward undertaking?
Any advice gratefully received.
acemcfly said:
Many many thanks for such a quick reply! As you used the term 'affliction' is it fair to say that it's not necessarily a fault?
My tyres are also quite cracked! Can you recommend the most appropriate tyre for my vehicle?
Kind regards...
No, it's not a fault, it's merely an unwanted side effect of modern steering geometry.My tyres are also quite cracked! Can you recommend the most appropriate tyre for my vehicle?
Kind regards...
Cracking with the Pirellis is a known issue. Probably worthwhile speaking to your local Pirelli dealer and seeing if they'll entertain a claim (providing the tyres aren't too old) their age can be found on the sidewall.
If you're not concerned about maintaining a Porsche warranty, fit a set of Michelin Pilot Sport PS4 S. The S on the end is critical.
acemcfly said:
I am new to Porsche ownership and own a 2014 Boxster which is on the 20 inch rims and p zero rubber. The front wheels feel as though they are skipping on full lock at very low speed. Once up to any speed the car runs absolutely true.
Is this normal firstly, and would it be sensible to go back to 18 inch wheels? And is this a straightforward undertaking?
Any advice gratefully received.
I believe it's a consequence of this, and I've experienced it on a variety of cars, including Porsches and BMWs:Is this normal firstly, and would it be sensible to go back to 18 inch wheels? And is this a straightforward undertaking?
Any advice gratefully received.
https://www.youtube.com/watch?v=YjMEPJgzUcI
I've had two 981 Boxster S cars back to back, both on 20" wheels with Pirelli P-Zeros. They both have the same issue - especially in reverse, but the second car has PTV and is MUCH worse in that regard. It literally hops across the ground at full lock, especially when it's wet. I believe it's due to Porsche not using Ackermann steering geometry. Kermit the Frog explains it here:
acemcfly said:
Pardon my ignorance but what is PTV?
Any advice on reverting to 19 or 20 in wheels?
I can't advise on wheel size as I've only driven cars on 20" wheels. PTV is Porsche Torque Vectoring. In the Boxster it's an optional but rarely fitted mechanical limited slip differential which improves traction hugely. It does this by resisting the rear wheels rotating at different speeds. That results in the car resisting very tight turns. On 911 models with PDK, they have PTV Plus which is similar but the degree of lockup is electronically variable. The car can allow much more slip at maneuvering speeds, which means the car can make tight slow speed turns much more easily. Might be worth checking if you have PTV on your car. I don't know how to tell by looking at the transmission directly, but if you give your dealer your VIN and ask for the build sheet you might see it on there. Here's how it looks on mine.Any advice on reverting to 19 or 20 in wheels?
Porsche Torque Vectoring.
I had 20” Turbo wheels on the 981s. It did the same thing. They all do it and after I realised that (like to many things with Porsche), it didn’t bother me anymore. In the let, loads of cars do it. Our current and previous Skoda Superb does it, particularly in wet or oily floored multi storey car parks.
The GTS 4 - not sure yet - not noticed, but it probably does. Not a problem and never caused scary moments or uneventful tyre wear. It does have PTV, but that clearly hasn’t made in more noticeable for me.
I had 20” Turbo wheels on the 981s. It did the same thing. They all do it and after I realised that (like to many things with Porsche), it didn’t bother me anymore. In the let, loads of cars do it. Our current and previous Skoda Superb does it, particularly in wet or oily floored multi storey car parks.
The GTS 4 - not sure yet - not noticed, but it probably does. Not a problem and never caused scary moments or uneventful tyre wear. It does have PTV, but that clearly hasn’t made in more noticeable for me.
Twinfan said:
Michelin PS4Ss if you're not using an extended warranty or not planning to have one in the near future.
If you are, you'll need something N-rated but I don't know what's available which may vary depending on which wheels you're running.
I have N rated 20" PS4S on my 981 CS with extended warranty. Much better than P Zero's, but still 'skip' in colder months.If you are, you'll need something N-rated but I don't know what's available which may vary depending on which wheels you're running.
I'm not sure why others are saying no to PS4S if you have a warranty? I just fitted them all round on my 981's 20" wheels and they're N0 marked.
I've had PZeros - crap and cracked, Goodyear Eagles - good but split all around insides of the fronts. Don't like Bridgestones. So PS4S the only option, and most say they're the best.
I've had PZeros - crap and cracked, Goodyear Eagles - good but split all around insides of the fronts. Don't like Bridgestones. So PS4S the only option, and most say they're the best.
Gassing Station | Boxster/Cayman | Top of Page | What's New | My Stuff