hanyoung99
Member
Another alternative might be PPF film along the side - hopefully that might help prevent nicks in the paint.
Wheel Spacers on the SE
- Thread starter F14Scott
- Start date
- Replies 26
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Tetrodotoxin
Well-Known Member
I decided to jump on the bandwagon and install the same spacers today. I was skeptical but I really love the change. I'm qualified to describe it properly but the steering has changed for the better.
Tetrodotoxin
Well-Known Member
I meant to say that I'm NOT qualified to properly describe the steering difference ... but subjectively I like the steering better now.
As I said, I was skeptical but I really love the change in both appearance and ride.
And it sets the stage for my switch to 215/50/17 tires, probably next year. This will give me 16% more sidewall for crappy Tennessee roads.
As I said, I was skeptical but I really love the change in both appearance and ride.
And it sets the stage for my switch to 215/50/17 tires, probably next year. This will give me 16% more sidewall for crappy Tennessee roads.
Tetrodotoxin
Well-Known Member
It's an increase of 5% in diameter and has been tested by other forum members:
https://www.insideevsforum.com/community/threads/12-mm-spacers-and-new-tires.11992/
https://tiresize.com/comparison/
https://www.insideevsforum.com/community/threads/12-mm-spacers-and-new-tires.11992/
https://tiresize.com/comparison/
SameGuy
Well-Known Member
I’m no expert, but 5% seems like a fairly big hit in terms of gearing, especially in a car with less than 200 lbf⋅ft, weighing over 3100 lbs. Going to a final drive ratio 5% taller in a muscle car has a profound effect on acceleration and drivability, like replacing 4.10 gears with 3.89s. I suppose if all you’re doing is cruising on the freeway at 65, no biggie, but in stop and go urban and suburban traffic, I think it might be an issue. Just my 2¢.
JasonMiller
New Member
Hey, I ran into the exact same puzzle with my M3. You are right to be careful about the studs.
Short answer: since you have the Performance brake upgrade, your rotor hats are thinner than the base SR setup, so the factory wheel studs stick out further. That is why a 15mm spacer can sometimes leave the studs poking past the spacer face, which is not something you want.
For your combo, 2020 M3 SR + Performance brakes + factory 19" sport wheels, you generally have a few safe paths:
I used a Tesla Model 3 wheel spacer fitment guide to check the offset math and factory specs before buying. It breaks down the bolt pattern, center bore, torque spec, and what thickness actually does to your effective offset.
My personal take: start with 15mm front / 20mm rear forged hub centric wheel spacers. That usually gets the 19" sport wheels close to flush without rubbing on stock suspension, and the forged piece gives you a better safety margin on a heavy EV than cast. Torque to 140 Nm, re-torque after 50 miles, and check clearance at full lock before you hammer it.
What tire size are you running? That changes the flush equation a bit.
Short answer: since you have the Performance brake upgrade, your rotor hats are thinner than the base SR setup, so the factory wheel studs stick out further. That is why a 15mm spacer can sometimes leave the studs poking past the spacer face, which is not something you want.
For your combo, 2020 M3 SR + Performance brakes + factory 19" sport wheels, you generally have a few safe paths:
- Run a spacer thick enough to completely swallow the stud protrusion. On most people setups with the Performance brakes, that means 20mm in the rear and at least 17mm up front, or just go 20mm all around if you do not mind a little poke.
- Use a hub-centric spacer with the correct cavity depth for the OEM wheel. The 19" sport wheels have a deeper pad pocket than the 20" Performance wheels, so a 15mm spacer can work if the spacer is machined with a recess.
- Have a shop trim the factory studs down. It is not my favorite route, but it is done.
I used a Tesla Model 3 wheel spacer fitment guide to check the offset math and factory specs before buying. It breaks down the bolt pattern, center bore, torque spec, and what thickness actually does to your effective offset.
My personal take: start with 15mm front / 20mm rear forged hub centric wheel spacers. That usually gets the 19" sport wheels close to flush without rubbing on stock suspension, and the forged piece gives you a better safety margin on a heavy EV than cast. Torque to 140 Nm, re-torque after 50 miles, and check clearance at full lock before you hammer it.
What tire size are you running? That changes the flush equation a bit.