Downsized M3 Performance to 18 inch wheels

[nj1266]

I put new wheels and tires on my M3P. I downsized from 20x8.5 to 18x8.5 wheels and upsized the tires from 235/35/20 to 255/40/18. This will be my track set-up and my daily driving set-up. I know the larger wheels look better, but they are easy to damage with curb rash and potholes. The car rides better and the steering is better weighted to my liking in Sport mode. In the 20 inch the steering felt too heavy in sport mode.

I just need the new TPMS to read the new psi on the tires. These are units I bought from America’s tire. From what I have read it takes a number of miles for the car to learn the new set-up. I already reset the tpms amd selected the 18 inch wheels from the menu. I am not getting an error message. Does anyone know how long it takes for the PSI to display on the screen?

The wheels are Konig Dekagrams and the tires are Yokohama Advans. I got them from America’s Tire. The combined weight is 46 lbs about 7 lbs less per corner than stock.

 

[lbowroom]

You’re right, they look terrible. Rolling diameter actually looks smaller too. But hey, if they function for you, cool.

 

[P3dStealth]

You need to black out the chrome now. The black wheels don't match.

I'm in NY. While 20in wheels look great I'd prob go through 1 a month.

 

[nj1266]

You’re right, they look terrible. Rolling diameter actually looks smaller too. But hey, if they function for you, cool.

Only by 1/2 an inch. If I go with a 45 profile tire instead of 40 profile tire then the rolling diameter will be 1/2 an inch larger. A higher profile means more tire roll over at the track under cornering especially on a stock suspension with no possibility of camber adjustment. I also. prefer the odometer to be 59 mph accurate and read 60 error than the other way around.

 

[Tanis]

And faster acceleration as well, with a smaller and lighter wheels! I like the rally/race look wheels!

 

[BetterSlowDown]

I much prefer the 18's and like the more purposeful look. In 2 prior cars the last few years I did the same thing, switching from 20
s to 18's in one case and 17's in another. For acceleration and comfort, the smaller wheels perform much better. I've been curious as to whether any 17's would work, actually, for my P3D-. I may pick up a second set of wheels myself and if 17's aren't an option, I'll be looking into lightweight 18's that don't break the bank.

 

[nj1266]

You need to black out the chrome now. The black wheels don't match.

I'm in NY. While 20in wheels look great I'd prob go through 1 a month.

I agree with you. I called a shop near me and got a quote for 750$ without the emblems. Is that too much?

 

[SigNC]

i'm sure those ride better but they look terrible in comparison.

 

[lbowroom]

And faster acceleration as well, with a smaller and lighter wheels! I like the rally/race look wheels!

the car isn’t torque limited, so wouldn’t the largest rolling diameter actually be the best choice for acceleration?

 

[nj1266]

i'm sure those ride better but they look terrible in comparison.

The pictures do not do them justice. In real life they look much better.

 

[Tanis]

the car isn’t torque limited, so wouldn’t the largest rolling diameter actually be the best choice for acceleration?

The weight saving makes the biggest difference. Many comparison tests on youtube, show faster acceleration with lighter wheels.
Not sure about the diameter. If the car is limited on torque to prevent tyre slipping with the smaller wheels, than it wouldn't matter, I agree.

 

[Watts_Up]

The wheels are Konig Dekagrams and the tires are Yokohama Advans.
I got them from America’s Tire. The combined weight is 46 lbs about 7 lbs less per corner than stock.

I also plan to switch to 255.

Did you get the Yokohama Advan Sport V105, Apex V601, or Sport A/S+?

I had the Yokohama 509 on my previous car and really like them.

 

[Teedub21]

Seem like for the track (and aesthetics) a 18x9.5 would’ve been better. With a 265/40-18 tire overall diameter would’ve stayed the same.

 

[nj1266]

Seem like for the track (and aesthetics) a 18x9.5 would’ve been better. With a 265/40-18 tire overall diameter would’ve stayed the same.

If you can find an affordable 18x9.5 that fits. My concern with a 265 tire is too much sidewall flex under cornering especially on a 3 with a stock suspension that doesn't allow camber adjustment.

 

[nj1266]

I also plan to switch to 255.

Did you get the Yokohama Advan Sport V105, Apex V601, or Sport A/S+?

I had the Yokohama 509 on my previous car and really like them.

I got the Apex V601. They are just a step below the Michelin Sport 4s that come stock on the 3P.

 

[nj1266]

As one of you suggested, I got Chrome delete done on the car as well as PPF on the front of the car and tinted all the the glass areas. It looks much better now with the black wheels than before

 

[Mash]

the car isn’t torque limited, so wouldn’t the largest rolling diameter actually be the best choice for acceleration?

If it won't be torque limited - it would be 1.8 sec 0-60 on 4S tires...

 

[cptpizzo]

As one of you suggested, I got Chrome delete done on the car as well as PPF on the front of the car and tinted all the the glass areas. It looks much better now with the black wheels than before View attachment 560424View attachment 560425

I like the look and am contemplating the 18s as well - but i think what would really set this right is it being lowered to minimize that SUV like gap.
AP

 

[nj1266]

I like the look and am contemplating the 18s as well - but i think what would really set this right is it being lowered to minimize that SUV like gap.
AP

This new wheel/tire combo is 1/2 an inch less in diameter than stock. Had I used a 255/45 tire then the wheel/tire combo diameter would have been 1/2 larger than stock and that might have filled the wheel well better. For The next set of tires, I will try a 255/45 size tire. I think the look will be better, but the handling prowess will be a bit less due to the larger sidewall.

 

[Mash]

This new wheel/tire combo is 1/2 an inch less in diameter than stock. Had I used a 255/45 tire then the wheel/tire combo diameter would have been 1/2 larger than stock and that might have filled the wheel well better. For The next set of tires, I will try a 255/45 size tire. I think the look will be better, but the handling prowess will be a bit less due to the larger sidewall.

My experience that stiffness and curve of sidewall on specific tire models and load rating influences sharpness more than tire sidewall height.