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Discussion Starter #1
I've read a good few posts on here with regards to aftermarket wheel widths people are running, but offset seems to be a little more difficult to find an answer to.

I have a 2008 v8 currently with oem 19" alloys. I've found some wheels that I think might work but I'm slightly worried the offsets are too low.

20" 9j et34
20" 11j et21

These are the highest offset they do in this specific wheel. Fronts would be 17mm further out and rears 29mm more. Just been out with the tape measure and am thinking I won't get away with it.

What offsets have you guys used without major rubbing issues?

Thanks
Adam
 

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Gotta ask: why 20s?
You’ll loose ride suppleness and a bit of performance loss by going that route.
 

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Discussion Starter #4
Purely for aesthetics, I'll be keeping the 19's in case of track days etc. I understand the 20"s aren't the greatest choice for performance but I can live with the slight loss. I don't usually drive hard on the road any way.


Gotta ask: why 20s?
You’ll loose ride suppleness and a bit of performance loss by going that route.
 

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Purely for aesthetics, I'll be keeping the 19's in case of track days etc. I understand the 20"s aren't the greatest choice for performance but I can live with the slight loss. I don't usually drive hard on the road any way.
I can appreciate that. Enjoy!
 

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Gotta ask: why 20s?
You’ll loose ride suppleness and a bit of performance loss by going that route.
I have the opposite experience on the R8V8,
a) NO loose of ride suppleness at all, ride quality is better and especially the "rippling" at full lock is completely gone.
b) gain of performance: less to no understeer, more grip and higher speed in curves. At track Anneau Du Rhin I am 1,5sek faster with 20" then 19", both Pirelli Zero RO1 Audi Spec and 305 back only front is a 9X20 with 245/30/20 compared to 235/35/19 on 8.5x19. the 20"RF2 Rohana+tyre are 500g, the rear 1kg lighter then the OEM 19" with tyres (the lightest optional ones).
this is mostly the first root cause why 20" are considered less comfortable and performance...they weight considerably more especially if the are not forged and taken care that barrel of the wheel is as light as possible.
Second root cause: 25 "full" rubber tyre. Trick is to use 305/30/20 on the rear, not the 305/25/20. On the V8 it gives you a slightly longer end ratio which is great for gear 1-3 and neutral/great if tuned for gear 4-6. 245/30/20 and 305/30/20 is OEM performance setup plus winter setup on Gen2.
No manufacturer is using a 25 height on 20" and they all know why:
a) loss of grip as the tyre cannot reform his whole surface to street= in approx 80% of time only 60-80% of the surface of a 305/25 tyre is actually "connected" to the tarmac, the worse the road the higher the loss in grip is (for acceleration/braking/g-force+side force!!!)
b) the side wall is too small and stiff to contribute to the damping=harsh ride plus
c) the contribution of the damping of a 30 height tyre is also constructed into /part of the suspension setup= you screw the suspension setup up with a 25 height
d) due to rear and front has bigger diameter lowering is not necessary as wheel arches are full or -10 till 20mm lowered like with GT coil overs gives you the max performance=enough suspension travel and looks mental plus less danger for your front splitter as its with -15mm standard right height on 19" OEM without lowering.

Take all this into consideration and choose the 20" plus tyres due to this requirements and you have no losses, only gains on an R8 (!!!) .But 95% chose their 20" due to optics and most are made for optic reasons.
why: R8 gen 1 was developed on 20" but then put on 18/19 due to Co2 (gen 2 is on 19 due to this) and no proper 20" sport tyres where available at that time (whats today 20" was 19" in 2006). This is the real reason why the preface v8 damping is so soft/comfortable compared to a facelift V10 without MR. Also Audi done all their track tests with Gen2 on 20" but the cup2 or trofeos would have been also available in 19" sizes and 19" wheels would also fit over the ceramic breaks.
 

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I have the opposite experience on the R8V8,
a) NO loose of ride suppleness at all, ride quality is better and especially the "rippling" at full lock is completely gone.
b) gain of performance: less to no understeer, more grip and higher speed in curves. At track Anneau Du Rhin I am 1,5sek faster with 20" then 19", both Pirelli Zero RO1 Audi Spec and 305 back only front is a 9X20 with 245/30/20 compared to 235/35/19 on 8.5x19. the 20"RF2 Rohana+tyre are 500g, the rear 1kg lighter then the OEM 19" with tyres (the lightest optional ones).
this is mostly the first root cause why 20" are considered less comfortable and performance...they weight considerably more especially if the are not forged and taken care that barrel of the wheel is as light as possible.
Second root cause: 25 "full" rubber tyre. Trick is to use 305/30/20 on the rear, not the 305/25/20. On the V8 it gives you a slightly longer end ratio which is great for gear 1-3 and neutral/great if tuned for gear 4-6. 245/30/20 and 305/30/20 is OEM performance setup plus winter setup on Gen2.
No manufacturer is using a 25 height on 20" and they all know why:
a) loss of grip as the tyre cannot reform his whole surface to street= in approx 80% of time only 60-80% of the surface of a 305/25 tyre is actually "connected" to the tarmac, the worse the road the higher the loss in grip is (for acceleration/braking/g-force+side force!!!)
b) the side wall is too small and stiff to contribute to the damping=harsh ride plus
c) the contribution of the damping of a 30 height tyre is also constructed into /part of the suspension setup= you screw the suspension setup up with a 25 height
d) due to rear and front has bigger diameter lowering is not necessary as wheel arches are full or -10 till 20mm lowered like with GT coil overs gives you the max performance=enough suspension travel and looks mental plus less danger for your front splitter as its with -15mm standard right height on 19" OEM without lowering.

Take all this into consideration and choose the 20" plus tyres due to this requirements and you have no losses, only gains on an R8 (!!!) .But 95% chose their 20" due to optics and most are made for optic reasons.
why: R8 gen 1 was developed on 20" but then put on 18/19 due to Co2 (gen 2 is on 19 due to this) and no proper 20" sport tyres where available at that time (whats today 20" was 19" in 2006). This is the real reason why the preface v8 damping is so soft/comfortable compared to a facelift V10 without MR. Also Audi done all their track tests with Gen2 on 20" but the cup2 or trofeos would have been also available in 19" sizes and 19" wheels would also fit over the ceramic breaks.
Do you have experience with 305/30/20 on the R8? If so are there any rubbing issues if the car is lowered about an inch? I just picked up some 20" rims and now shopping for tires. I really want to go with the PS4s.
 

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At track Anneau Du Rhin I am 1,5sek faster with 20" then 19", both Pirelli Zero RO1 Audi Spec and 305 back only front is a 9X20 with 245/30/20 compared to 235/35/19 on 8.5x19. the 20"RF2 Rohana+tyre are 500g, the rear 1kg lighter then the OEM 19" with tyres (the lightest optional ones).
this is mostly the first root cause why 20" are considered less comfortable and performance...they weight considerably more especially if the are not forged and taken care that barrel of the wheel is as light as possible.
That's an interesting observation. However, I think you may be comparing two generations of PZero which one would expect to influence the result. The 19" RO1 spec are the old PZero, the 20" RO1 spec (245/30 & 305/30) are the new PZero also known as PZ4 which should be visible on the sidewall - compound has been further progressed and different tread pattern.

Good point though. With the advancements in tyre technology, 20" low profile tyres are not the nightmare they used to be 15 years ago. I remember putting a set on a V8 Mustang early 2000s with more than a few scary moments.
 

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Pirelli Zero RO1 Audi Spec and 305 back only front is a 9X20 with 245/30/20 compared to 235/35/19 on 8.5x19. the 20"RF2 Rohana+tyre are 500g, the rear 1kg lighter then the OEM 19" with tyres (the lightest optional ones).this is mostly the first root cause why 20" are considered less comfortable and performance...they weight considerably more especially if the are not forged and taken care that barrel of the wheel is as light as possible.

[/QUOTE]

Hi Helldriver, I agree many 20" rims are a lot more heavier than the 19" but where do you get the info about 20" Rohana RF2 vs 19 Audi OEM 19"??

The Audi OEM 19" 8,5x19 ET42 is 9.25kg and the rear 11x19 ET50 is 11.1kg so its a total of 18,5+22.2=40.7 kg

The info ive found about Rohana 20" is that the 11x20 seems less heavy (20x11= 23.45lbs = 10.64kg) however the front 9x20 is a lot more heavy (20x9 = 24.25lbs = 11.0kg) making a total 21.28+22=43.28kg



Soo... Rohana 20" approx 2.5kg more. Can you please verify because Id love to go to 20" rims I just have not found any 20" rims (that not cost a fortune) that are below audi oem.19" total 40.7kg yet.

Or did you compare weight including the Pirelli tyres? Comparing against Michelin PS4S?

I follow your wheel advice using 245/35 front and 305/30 but using 19" rims meanwhile 😊👍
 

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I moved to 20" wheels with Toyo Proxy TR1 tires: FRONT: 245/30/ZR20 REAR: 305/25/ZR20 on my 2011 V10 Spyder.

I have to say that in almost every way, handling, feel, looks, grip, etc... they feel better than the stock 19s.

I initially tried 20s for the look but was pleasantly surprised with the results. I have kept the original 19s for the next owner, but will not go back.
 

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BTW: Here is my car with the 20s. They were take offs from a 2017 Plus.
245482
 

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Both articles do conclude that “+1 sizing” over OEM wheels will generally sacrifice some comfort and introduce a higher level of NVH, but that overall performance increases more significantly than what is lost.

Now although the laws of physics, the principles of aerodynamics, the coefficient of friction, and the properties of materials and dynamic systems apply equally and identically regardless of the type of car...

The caveat is that the UK article used a Volkswagen GTI, and the US article used a BMW 328i. So how much of the measurements and empirical results from a front-drive hot hatch or a rear-drive sports sedan - both with front mounted engines - translates to a mid-mounted engine supercar can probably be debated until pigs fly while carrying cows home.
 

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I've read a good few posts on here with regards to aftermarket wheel widths people are running, but offset seems to be a little more difficult to find an answer to.

I have a 2008 v8 currently with oem 19" alloys. I've found some wheels that I think might work but I'm slightly worried the offsets are too low.

20" 9j et34
20" 11j et21

These are the highest offset they do in this specific wheel. Fronts would be 17mm further out and rears 29mm more. Just been out with the tape measure and am thinking I won't get away with it.

What offsets have you guys used without major rubbing issues?

Thanks
Adam
Those offsets are way to much. I have that size wheels and mine are flush with fenders at 20x9 +39 front and 20x11 +33 rear your wheels will stick out too far
248368
 
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