245s on RS4 Avant

[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

[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

[TonyRockyHorror]

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

[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).

[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

[adsgreen]

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%.

[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.

[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

[adsgreen]

Don't forget aquaplanning... wider tyres are more susceptible to this.

[adsgreen]

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

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.

[TonyRockyHorror]

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.

[mac4RS]

I've been running 275's for 3 years now - wouldn't have anything else.

[RIV]

I've been running 275's for 3 years now - wouldn't have anything else.

[brn7y]

Any pics?

[sync24]

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

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