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M50 19” wheels front tires

620 Views 21 Replies 8 Participants Last post by Jonathan S., 2 d ago

Alexpapas

Discussion Starter · 6 d ago

Has anyone fitted 255/40 to the front to make a square setup?
Is there enough room?
The OEM stagger between front and back seems minuscule - 245/40 v 255/40- less than .4 of an inch, so it intuitively seems like it should work

1 - 20 of 22 Posts

WallyF

· #2 · 5 d ago

I wonder the same thing. The only concern that I can see is if the larger tire hits the fender edge. There should be sufficient room on the strut side.
I would prefer running a square setup so that I can rotate the tires on my eDrive40.
Wallyf

J_P

· #3 · 5 d ago

WallyF said:
The only concern that I can see is if the larger tire hits the fender edge.

In the UK it is illegal to have the tyres protrude from the wheel arch. Not sure what the situation is in America and if the wider tyres would do that.

toosteeley

· #4 · 5 d ago

Lots of owners have added 10mm spacers to the front and the tires still tuck inside the fenders. Therefore, going to a 255/40 tire on the front (adding 5mm per side) shouldn't pose any issues as far as protruding outside the wheel arch.

Having said that, I'm not sure what the clearance is on the inner control arm, so you may need a small spacer (but I doubt it). Even with a 5mm spacer and 255/40 tires, that's comparable to adding a 10mm spacer with stock tires.

Reactions: 1

i4eD40

· #5 · 5 d ago

Should be fine without knowing the offset between the 19" and the 20" I mention the 20" since if you get the 20" option it uses the same width 8.5" but you get 255/35/20 tires up front. This does not require any addon fender extension in the front. So as long as the offset is close enough you should be able to fit 255 on the front. If it works let us know, I want to fit 255 up front when the times comes to get new tires.

Reactions: 2

Alexpapas

Discussion Starter · #6 · 5 d ago

Does anyone know if the 19” wheels are the same width? I would imagine they are, given that the tire width difference between front and back is about 3/8” or 39 mm
If they are the same width then fitting the 255 in the front should really present no problem, especially given that the 20” front wheel well accommodates a 255 width tire.

Jonathan S.

· #7 · 5 d ago

Alexpapas said:
Does anyone know if the 19” wheels are the same width? I would imagine they are, given that the tire width difference between front and back is about 3/8” or 39 mm
If they are the same width then fitting the 255 in the front should really present no problem, especially given that the 20” front wheel well accommodates a 255 width tire.

They are not the same.
I looked this up when I set up full-size spares.
(Plenty of Audi A8 wrecks on eBay for nearly free wheels, even including shipping!)
If I'm interpreting my notes correctly, front is 19x8.5 ET35, rear is 19x9 ET42.
Each wheel spec is within the range for accommodating each tire size. Which makes the minor staggering for both wheel and tire kind of frustrating (i.e., kind of the worst of both worlds, lack of front<>rear rotation but not much of an apparent performance benefit relative to a square setup).

Reactions: 1

i4eD40

· #8 · 5 d ago

Alexpapas said:
Does anyone know if the 19” wheels are the same width? I would imagine they are, given that the tire width difference between front and back is about 3/8” or 39 mm
If they are the same width then fitting the 255 in the front should really present no problem, especially given that the 20” front wheel well accommodates a 255 width tire.

19" vs 20" for the fronts, they are the same at 8.5" From the internet data I found the 20" also ET35 offset, so it should fit fine. I will also provide a warning that not all tires are the same width as indicated. EG a lot of BMW star spec tires are actually wider than the indicated size.

FWIW 20" rear is 10" wide with offset of ET39.

Edit, as Jonathan S. stated, rears are .5" wider for the 19"

Reactions: 1

i4e35nvbc

· #9 · 5 d ago (Edited)

I know this may sound a little odd but I know that on a few Audi cars the front tires are wider than the rears and done intentionally to help neutralize understeer that Audi's will typically have since they are quattro all wheel drive... so perhaps you can 'simply' swap the fronts to the backs and vice versa to be able to manage tire wear more evenly??? I have also ordered wheel spacers for my car which I am MUCH anticipating to pickup in a couple of weeks so my thought would if I did this I wouldn't put the front wheel spacers on if the 255's are on the front? Am I talking nonsense???

Actually, maybe it was for front wheel drive Audi's only they put wider tires on the front vs the back... now I can't remember which but they do DO this on other vehicles is my main point lol

Jonathan S.

· #10 · 5 d ago

^ Huh, interesting, never knew this was a thing:

Everything You Need To Know About Reverse Staggered Wheel and Tire Fitments – APEX Race Parts Blog

www.apexraceparts.com

www.apexraceparts.com

i4e35nvbc

· #11 · 5 d ago

Jonathan S. said:
^ Huh, interesting, never knew this was a thing:

Everything You Need To Know About Reverse Staggered Wheel and Tire Fitments – APEX Race Parts Blog

www.apexraceparts.com

Aha! See! I knew I wasn't going bonkers lol...

Alexpapas

Discussion Starter · #12 · 5 d ago

Besides the 10mm greater width of 255 v 245 I also calculated that the total height from the ground will be 8mm more which is relatively insignificant.
This all interesting. If my car is delivered with Max Performance tires I like, I’ll probably leave them alone, but given that this car also drives the front wheels under hard acceleration it might make sense to have a square setup with slightly wider tires in front to match the rears.
Also I guess the tires have to handle the added weight of an EV as well as the dramatically different increased torque.
All these things to ponder while my car waits for a boat…..

Normimb

· #13 · 4 d ago

Alexpapas said:
Besides the 10mm greater width of 255 v 245 I also calculated that the total height from the ground will be 8mm more which is relatively insignificant.
This all interesting. If my car is delivered with Max Performance tires I like, I’ll probably leave them alone, but given that this car also drives the front wheels under hard acceleration it might make sense to have a square setup with slightly wider tires in front to match the rears.
Also I guess the tires have to handle the added weight of an EV as well as the dramatically different increased torque.
All these things to ponder while my car waits for a boat…..

Normimb

· #14 · 4 d ago

Total height difference would be 4mm. Sidewall increase 4mm.

Alexpapas

Discussion Starter · #15 · 4 d ago

Normimb said:
Total height difference would be 4mm. Sidewall increase 4mm.

It is two sidewalls - top and bottom
Therefore 8mm

Normimb

· #16 · 4 d ago

Only one side of the wheel is touching the ground. 4mm is the real increase in height.

Alexpapas

Discussion Starter · #17 · 4 d ago

Seriously?
If you measure the diameter of the wheel and tire from top to bottom it is 8mm taller than a 245/40. That’s just simple math. The sidewall is 4mm taller but if you simply look at the tire you see two sidewalls - one on top of the wheel and one on the bottom. What is important is if it will fit in the wheel well and you have to take the full measurement into account.

Normimb

· #18 · 4 d ago

You are wrong. The car height increase by only 4mm. The diameter of the wheel is 8mm taller you are correct on this but the car is not sitting on top of the wheel. The wheel is connected to the car in the center (at it's rayon) Half of the wheel. You understand?

Normimb

· #19 · 4 d ago

Are you talking about the height increase of the car? Because that's what i thought you were talking about. If you were talking about height increase of the wheel only then you are correct. Maybe a misunderstanting.

Alexpapas

Discussion Starter · #20 · 4 d ago

Normimb said:
You are wrong. The car height increase by only 4mm. The diameter of the wheel is 8mm taller you are correct on this but the car is not sitting on top of the wheel. The wheel is connected to the car in the center (at it's rayon) Half of the wheel. You understand?

You are really not understanding.
I’m not referring to the car height at all. I’m referring to the wheel and tire height.
It is 8mm taller than a 245/40 wheel tire combo. Of course the total height of the car increases only by the single tire sidewall because that is all that has been lifted off the ground from the center of the hub. It is the total tire wheel combo that is 8mm taller. The question that is relevant here is:
is there an additional 4mm of space above the hub inside the wheel well?

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