Sponsored by The Tire Rack

[MrBlueSkies]

Has anyone experienced running both 18" and 19" wheels with the same suspension setup? How does the handling and steering response compare? Currently on M359 19s. It looks like 18s are the easiest way to reduce unsprung weight, but will it compromise the very goal I am chasing, to sharpen up the handling and steering response?

[omgzirra_exe]

ran both on the same settings, 19s are just heavier up front. so heavier steering. smoother ride though lol.

[Timeattackauto]

what size tires were you running with both setups if you don't mind me asking?

[Longboarder]

What are you trying to achieve? Street or track?

Steering response will feel sluggish with wider front tires, no matter if 18 or 19. I ran a 275 front at the track on light Apex wheel and turn in response felt like I was steering a boat with a slight delay but the trade off of far more grip was a good compromise. On the street was terrible for me. For me precise steering is very important. I dumped a BMW M8 only after a few months and took a big loss because I didn't like the steering. Stupid me.

General rule is the narrower the tire and the higher negative camber in the front, the better and more precise the steering will feel. Toe also plays a role but wouldn't advise much toe unless a dedicated track car becauae a lot of toe will chew up the inside of your tires real quick.

I have two sets of the M359 wheels and both sets upsize to 255's in the front. One set with Michelin PS4S the other set with Cup2's. Also did camber plates on the stock comp package suspension to get -2.3 front camber and steering feel is nice and precise as good as my 911's.

[Timeattackauto]

For me it will be street sprinted driving and some track driving. this isn't a daily for me. i would like to get some M359's if i stay 19's or some apex ARC8's or EC7's if i go 18's.

[Thumbie]

FWIW if your goal is purely handling, all the guys I know who regularly track their e9Xs run some variation of an 18x10 square setup. Some run 9.5" wide, or some other variation of offset/spacer combo. But almost all are 18" not 19" and are square (ie same width on all 4).

And for alignment, some of the more aggressive track drivers have close to -4 camber up front and 0 toe (do not recommend for DD/street)

[Z K]

Very few people will want to track on 19" if 18" wheels fit on the car. Lighter weight, much more tire selection as a well as lower tire prices.

As for responsiveness and handling, that is really dependent on the tire itself. Something soft like a Michelin PS4S street tire will give you a softer ride and less responsive handling. Most track oriented tires will have stiffer sidewalls and will make the car feel more responsive to inputs. You have to account for tires when looking at wheels as well - they are huge factor in how the car drives.