Wheels, tires and ride comfort.
 

Hi guys! Frequent lurker, first time poster here! Currently drive a stock BRZ.

I was wondering this: How much does wheel weight and tire selection affect ride comfort?

I've been finding the ride in the BRZ a bit harsh over rough roads and highway expansion joints, with road imperfections sending vibrations through the car and highway expansion joints almost as if tossing or jolting the occupants. To be honest, the stock wheels don't bother me too much style-wise, but if dropping a couple pounds from each corner could remedy the harsh ride it would be something I'd consider. How much of the ride is in the tires? I'm still on the stock Primacies, and would be looking to swap to the Michelin PSS or a Potenza tire in 225/45 for more grip and a bit more sidewall.

Tires: considering Michelin PSS in 225 for the stockers or 17x8 wheels, but don't really like the rounded sidewall/balloon shape, or Potenza RE003 (closest thing on TireRack is probably the S04 Pole Positions), which have a much squarer profile that I like. I've also always run sticky Potenzas (RE11 on my RB3 Odyssey) so I'm a bit biased, but all of my previous cars have been more comfortable than the BRZ. Downside is that the Potenzas have stiffer sidewalls and weight more than the PSS.

Wheels: I was considering 17x8 RPF1s (15-ish lbs per corner). I'd have to think much harder about going even lighter as the TC105N and CE28N are in a completely different price range.

I get it, this car handles great and rides not so great, but it'd be nice if the ride was a bit more... German. Stiff is fine, but perhaps a little less harsh would definitely be appreciated. Thanks in advance!

If you're not concerned with the aesthetics of smaller wheels, 16's may be a way to get some additional ride comfort. More sidewall, less weight, means more compliance.

There's a ton of information in this thread: http://www.ft86club.com/forums/showthread.php?t=27023

I'm running 16's with snow tires on them (not representative of a performance tire, certainly, and the switch from stock wheels/tires has certainly taken the edge off harsh bumps. When I'm shopping for wheel's, I'll be seriously considering going with 16's.

I have MPSS 225/45/17 on stock wheels and I don't think it looks balloon-y.

http://imgur.com/bWIGwn6.jpg
http://imgur.com/RuzCaOE.jpg

Generally speaking, the higher the second number (stock is 215/45R17), the softer the ride. Downside is generally less responsive handling. If you went with a 16" wheel to something like a 205/55R16 then it would be softer ride. 245/40R17 which is what I run in non-winter months is slightly less soft than stock. Going with 245/35R18 would be even less soft.

Side note: I can't really notice the difference between lighter wheels and heavier wheels, but some people can.

Wheel weight doesn't really affect ride comfort. Tire selection does. Thicker sidewalls yield more comfortable rides at the expense of responsiveness.

On another note, I think 17x8 rpf1s are great wheels for the car. They aren't too wide so the car is still playful, yet they're very light.

Actually, that looks perfect. Fears quelled. Did the ride change at all?

Was hoping the drop in unsprung weight alone could improve ride quality, but it sounds like my mileage could vary...

Also if we're talking only about tires, in the same size, would I be gaining/losing anything in terms of ride harshness when comparing the stock Primacies/PSS/Potenza?

For reference, my BRZ has the stock Primacies but I daily on the Potenza RE-11.

I recently changed to RE002s (can't get RE003s yet here). The ride is noticeably worse over Primacys it has to be said, but it's all worth it when you come to a corner. So much better.

In theory the greater the ratio of sprung to unsprung weight the better the ride. So reducing wheel weight will be more comfortable.

I noticed I dropped about 3 MPGs. Road noise went up a tiny bit, but it wasn't bad. When I first got them, it felt like initial turn-in was a little less precise, but that might have been my imagination. Ride quality didn't seem to change.

Regardless, once I got them on the track, I was thoroughly pleased.

Well, primacies are of low rolling resistance. No wonder of economy drop installing grippier tires. Every tire is compromise of sorts with different sorted priorities. One just has to choose tires that fit best his individual priority set. :)

Hi,

I would like to know if your car is lowered? (does not seem to be in these photos)
Also, do you have spacers?

I plan to replace the OEM Michelin with 225/45/17 Michelin Pilot Sport 4S and I am afraid that the tires will rub in the rear wings.

I currently have 25mm spacers and a drop of about 1.25"
The 215/45/17 are relatively close to the wings.

I read that some people with 30mm spacers and stock tires/rims had some rubbing.
Adding 10mm tire width (5mm each side) may create the same issue?

Does anyone here drive with 225/45/17 tires, 25mm spacers and a drop of about 1.25 "?

Thank you for sharing your thoughts.


(PS: I have consulted several conversations on this forum. Thank you for all the information present.
It helped me a lot and keep helping me in my choices of modifications.) :thumbsup:

Honestly I don't remember, as that was 3 years ago. I think I was at stock height then, and no spacers.

Nowadays I use 225s on stock wheels with 15mm spacers all around, and with around a 1.25" drop. No rubbing issues at all, but I also have an aggressive track alignment.

Do you mind sharing the specs on your alignment? I'm hoping to change mine soon to -3.2 f and -2.6 rear.

I had 225/45-17 tires on stock 17x7 wheels for about a year. Switching from stock Bridgestone Turanza 215/45-17 tires to Yokohama Advan 225/45-17 tires made a big difference in comfort and grip. The sidewalls did not bulge out, fit was perfect and within specs. If you want more grip, comfort, stability, 225 was noticeably better for me. If you are more into drifting, 215 could be better.