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245s on RS4 Avant

Posted: Mon Jan 28, 2013 10:38 am
by TonyRockyHorror
HI folks

Loving the car.

It came from Audi as an Approved Used Car last week. When Iw as checking the tyre pressure I noticed that it is fitted with 275/30/19s rather than 255/35/19s.

Is this common/an issue?

Tony Rocky Horror :bigwave:

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 10:58 am
by RIV
I've always run 275 with no issues, and in my opinion they look better, only thing to mention is they put your speedo out slightly

By the way you have written 245's on your heading not 275's

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 11:08 am
by TonyRockyHorror
Silas wrote:I've always run 275 with no issues, and in my opinion they look better, only thing to mention is they put your speedo out slightly

By the way you have written 245's on your heading not 275's

DUH!!

Thanks

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 1:04 pm
by MikeFish
You've got a tyre that is 20mm wider than standard but is also one size higher profile.
Width aside, you have effectively gone from 255/35 to 255/40 as (off the top of my head) 275/30 is the same profile as 255/35.

In my mind this has a negative effect of both performance and looks. A 265/30 would give you extra width without compromising the looks or handling (unless of course, you like the look of high profile tyres).

245s on RS4 Avant

Posted: Mon Jan 28, 2013 1:18 pm
by brn7y
Tyre Size Diameter Circumference Difference Speedo Fits Wheel Rim
---------- -------- ------------- ---------- ------ --------------
255/35 R19 662 mm 2080 mm 0.00 % 70.00 8.5x19 to 10x19
265/35 R19 668 mm 2099 mm 0.91 % 70.64 9x19 to 10.5x19
275/35 R19 676 mm 2124 mm 2.12 % 71.48 9x19 to 10.5x19

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 1:23 pm
by adsgreen
MikeFish wrote:You've got a tyre that is 20mm wider than standard but is also one size higher profile.
Width aside, you have effectively gone from 255/35 to 255/40 as (off the top of my head) 275/30 is the same profile as 255/35.

In my mind this has a negative effect of both performance and looks. A 265/30 would give you extra width without compromising the looks or handling (unless of course, you like the look of high profile tyres).
255/35 has a profile height of 255mm x 35% = 89mm
275/30 has a profile height of 275mm x 30% = 82mm

So the overall wheel will be a smaller radius and thereforce circumference than the stock wheel. Your speedo will overread by I guess about 2%.

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 1:50 pm
by sonny
Cons out weight the pros when running 275 vs 255.

Looks of the 275 being wide and filling the arches is the only pro I can think.

Cons, uncomfortable ride, more wear and tear on suspension, worst fuel economy, speedy slightly out, and zapping wheel power due to wide contact patch.

Avant is also heavier so that may add to the ride quality on the 30 profiles too.

2% is what I was thinking too, I was running 18s with a 35 profile and speedo irrc was 7% out, so engine was over revving at higher speeds.

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 1:52 pm
by RIV
You've got a tyre that is 20mm wider than standard but is also one size higher profile.
Width aside, you have effectively gone from 255/35 to 255/40 as (off the top of my head) 275/30 is the same profile as 255/35.

In my mind this has a negative effect of both performance and looks. A 265/30 would give you extra width without compromising the looks or handling (unless of course, you like the look of high profile tyres).
If you look at 275 compared to standard tyre's they look much better, and the handling is not affected in a negative way at all, the person I bought my car from used to race touring cars for many years and he was the one who changed to f1 asymetrics 275.30.19 they look better end of story :thumb:

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 3:40 pm
by adsgreen
Don't forget aquaplanning... wider tyres are more susceptible to this.

Re: 245s on RS4 Avant

Posted: Mon Jan 28, 2013 3:42 pm
by adsgreen
Silas wrote:
You've got a tyre that is 20mm wider than standard but is also one size higher profile.
Width aside, you have effectively gone from 255/35 to 255/40 as (off the top of my head) 275/30 is the same profile as 255/35.

In my mind this has a negative effect of both performance and looks. A 265/30 would give you extra width without compromising the looks or handling (unless of course, you like the look of high profile tyres).
If you look at 275 compared to standard tyre's they look much better, and the handling is not affected in a negative way at all, the person I bought my car from used to race touring cars for many years and he was the one who changed to f1 asymetrics 275.30.19 they look better end of story :thumb:
Lower profile tyres do reduce overall traction - it's no different to running firmer springs/dampers/arb's. The difference is that on a circuit that is generally considerably smoother than our fair roads the benefit is a more responsive car.
It "feels" better as the car is more direct even possibly twitchy... however as soon as you get to any kind of bumps then you will get a better result with softer suspension.

Re: 245s on RS4 Avant

Posted: Tue Jan 29, 2013 12:02 pm
by TonyRockyHorror
brn7y wrote:Tyre Size Diameter Circumference Difference Speedo Fits Wheel Rim
---------- -------- ------------- ---------- ------ --------------
255/35 R19 662 mm 2080 mm 0.00 % 70.00 8.5x19 to 10x19
265/35 R19 668 mm 2099 mm 0.91 % 70.64 9x19 to 10.5x19
275/35 R19 676 mm 2124 mm 2.12 % 71.48 9x19 to 10.5x19

Sensational. Thanks. So the 275/35 R19 fits the 9J x 19 wheel.


I called my insurer and declared it and they said no issue, so long as the speed rating on the tyre is the same.

So all good.


Nice place you've all got here.

:beerchug:

Re: 245s on RS4 Avant

Posted: Tue Jan 29, 2013 9:12 pm
by mac4RS
I've been running 275's for 3 years now - wouldn't have anything else.

Re: 245s on RS4 Avant

Posted: Tue Jan 29, 2013 9:22 pm
by RIV
I've been running 275's for 3 years now - wouldn't have anything else.
:beerchug:

245s on RS4 Avant

Posted: Tue Jan 29, 2013 9:55 pm
by brn7y
Any pics?

Re: 245s on RS4 Avant

Posted: Sun Feb 03, 2013 2:17 am
by sync24
TonyRockyHorror wrote: I noticed that it is fitted with 275/30/19s rather than 255/35/19s.
+1 I noticed tonight going through the latest doc from Audi tonight [unrelated] that my car also has 275x30x19's fitted - I never noticed before and just assumed I had 255x35x19's :oops:

I found this tyre calculator http://www.willtheyfit.com/, which gives you everything you need.
Basically, the speedo is out by -2%, there is a drop in ride height of -6.75 mm.

I'll have to think about what to do when they need replacing especially now as the car is being setup with KW coilovers on these tyres next week. Guess I will stick with 275's