Switching back to 17" Wheels from 18" for acceleration feel?
 

Anyone do this switch? I recently switched from the stock wheels to an 18 x 8.0 wheel with 225/40/18 Pilot Super Sports. The grip is awesome, but the acceleration "feel" is noticeably less quick. The 18"s have only been on for a day and already thinking of switching to a lighter weight 17. Should I just wait out the adaptation period for my senses to get used to it? How long did it take you to get used to the feel or did you never get used to it and just switched back?

Thanks

Did you get an alignment?

Not yet. Was waiting for my coil overs to be installed before doing that. Should I get the alignment now or just wait? Might be a couple more weeks until I get the coil overs on. Sorry, I'm a noob to all this.

Are the 18 inch wheels heavier than the stock 17s? It could just be the extra weight from the wheels.

The wheels are about 0.25lbs heavier. Not sure about the wheel + tire weight vs. stock tho.

Even if you kept the weight the same, it would still feel slower going to 18s. You've moved the mass further out.

alignment will help.

My BMW seemed to accelerate slower on PSS than Efficient Grip Performance. This is at odds with a g meeter says that the PSS are oh-so-slightly faster in 1st & 2nd. Just saying.

Why will this help?

I have never read anywhere that the weight difference with a +1 change will make a noticeable difference in acceleration or throttle response, despite the increased angular momentum from having more weight further from the axle .


Increased unsprung weight and shorter sidewalls will give you a harsher, possibly less well controlled ride

Why are people talking about alignments for straight line acceleration, when no suspension has been changed!! :mad0260:

The stock 17's are super heavy pieces of shit. 18's that are even heavier have more weight further away from the wheel center as abraxis stated. Further, both the 16 and 17" oem tires have fairly light sidewalls, so wider tires put even more weight away from the wheel center.

As far as I know even if you have a BBK you don't need 18's except for looks.
Looks =/= performance.

It's good that you noticed immediately that the car is sensitive to rotating mass. The oem suspension is sensitive to unsprung mass too. You have more tire grip which you noticed but likely have less mechanical grip right now. It works better the lower weight your wheels and tires are. That won't matter when you switch to stiff coils though.

If you increase from 17 to 18" tires and keep the same tire aspect ratio, then the circumference of the tire will increase.

A larger tire circumference will mean less available torque at the contact patch than before.
This would result in lower acceleration.

What size tire did you have before and what size tire after?