20" Vs 21" Wheels Comfort and Handling

[Nigel.newcombe]

21's all the way - my ST GTS is comfortable enough to justify bigger wheels and a slight (not really noticeable) loss in ride quality, the RS black wheels look the dogs.

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[Chas1]

I'm interested to see more informed opinions than mine from those with track/race setup experience- in the meantime, for what it's worth, I'd guess that wider tyres enable later braking (more grip and also, bigger wheels allow for bigger brakes), higher lateral grip and better acceleration off the line, but their lower profile means less sidewall to flex, so less progressive feel around the lateral grip limit (also less able to maintain contact when under high lateral load). So they might be more suited to disciplined smooth driving to get optimum lap times. OTH, the narrower, higher profile tyres on smaller wheels are more alive for fun driving (which is suboptimal for lap times), and have the advantage of more sidewall to flex to maintain contact under high lateral load (a reason why F1 tyres are so HIGH profile?).
(BTW I assume your PCM has been updated with your winter set)

Interesting observations, I’ll see how I get on but I will likely change back come the spring for looks alone. My PCM had its two day update and wheels changed over at the same time by Porsche Centre. But thanks for the reminder.

 

[f1eng]

21's all the way - my ST GTS is comfortable enough to justify bigger wheels and a slight (not really noticeable) loss in ride quality, the RS black wheels look the dogs.

I am surprised you didn't notice.
My first demo car had 20" wheels and I was super impressed by the ride.
The second time I drove a demo car, I was considering cancelling my order after a long wait, it was on 21" wheels and the first thing I noticed was how much poorer the ride was than I expected.

I nearly changed my order but didn't like the styling of any of the 20" wheels available for my car so didn't. The ride is acceptable but noticably worse IME.

I have 20" wheels of a style I like for my winter tyres and the ride is markedly better, as I experienced with 20" v 21" summer tyres on demo.

Ride is more important to me than looks - after all I can't see the outside when driving it - so at least I now have both sizes of wheel so could put summer tyres on the 20s if I want - but I probably won't.

 

[Bakerman911]

I'm still thinking about going to 22'' summer wheels

 

[tonykara]

The scrubbing has nothing to do with the wheel size.

I've heard that refuted by several sources now.

 

[Murph7355]

I've heard that refuted by several sources now.

In that wheel size has some impact on the geometry involved, maybe fair enough.

It's a common phenomenon covered by the Ackermann Effect.

 

[Taycan4S_UK]

I've heard that refuted by several sources now.

yo brought back to life a thread from 2023 with a reply..... we are in 2026

 

[69Mach390]

yo brought back to life a thread from 2023 with a reply..... we are in 2026

Welcome to the future!!

To be fair the topic (scrubbing and wheel size) are still things people will care about today.

On a related note for people who get a demo/loaner and notice a ride difference….

In addition to wheel size difference, some of that may just be because of newer tires (depending on how many miles your car has).

When my last car (Mach E) was in the shop, my loaner had the identical setup and tires, but both rode better and didn’t have the scrubbing.

When I got new tires for the Mach E, it both solved the scrubbing and rode better again.

Worn down tires can have both issues.

 

[tonykara]

yo brought back to life a thread from 2023 with a reply..... we are in 2026

I sure did! I’m new to the vehicle and I’m doing a lot of reading instead of blasting the forum with a pile of newbie questions.

The statement that I replied to is flat out wrong and it’s annoying to read stuff like that and let it propagate unchecked.

 

[69Mach390]

I sure did! I’m new to the vehicle and I’m doing a lot of reading instead of blasting the forum with a pile of newbie questions.

The statement that I replied to is flat out wrong and it’s annoying to read stuff like that and let it propagate unchecked.

It’s hard being new sometimes on a forum.

Either the old grumps yell at you for asking a question that’s been asked before or the old grumps yell at you for bringing back an old thread.

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