17 vs 18" Wheel Ride Quality?

I offered to trade my 18" Boxster wheels on here for 17" and got lots of responses. Hmmmm, am I being an idiot to do this? What is the $ value difference? Will it make much difference with ride quality? Anyone know? What about smoother riding tires? I got Yokohoma 225/40ZR18 in front and 265/35ZK18 in back. Help!
Thanks.-Bill (potentially "Dumbbell Bill")

Trade?

Dollar value varies alot. You can get a 'relative' idea on one type vs. another via Wheelenhancement.com and looking at all the wheels they sell - then email them and ask for their prices. It will give you a comparative value at retail - but could likely vary significantly depending on the market place (who likes what wheels, etc.)

I have an extra set of 17s that are the Boxster/996 type (see Wheelenhancement for a good photo) and I've been interested in getting some 18s for competition. I'd like to trade (plus appropriate $$ variance) depending upon which wheels you have. I'm looking for 7.5 and 9" wide that are relatively light like the thin five spoke, not the wider 8s and 10" wheels. You can find the widths you have by looking to each side of the valve stem for the markings... i.e 7, 7.5, 8 etc. What type of wheels do you have?

The ride quality is better on 17s and the rubber is cheaper and it's easier to find a variety of compounds and treads and 'softer' sidewalls for a more touring style of driving. The 18s are arguably better for competition because they'll incorporate lower profile/ stiffer sidewall tires for better response... and a harsher ride and more potential for damage to the wheels if encountering a severe pot hole.

kj

Details on 18" Wheels

Hi,
Please see attached photos. I can't tell what width of tires are.
-Bill

They look like

the 993 Turbo Look wheels and although they're very nice looking, I think they're relatively heavy. Several people on this board actually prefer them as a daily driver or everyday wheel because they compliment the car so well.

kj

very heavy

Those wheels are "boat anchors" I had a set with Dunlop SSRs size 265x35 and the tire wheel combo weighed about 55 lbs.
That is why I got rid of them. The 17s are about 15-20 lbs lighter, for the wheel tire combo.
They are a great, nice looking street wheel but not preferable for track wheels.

When selling or trading in your car, you get a credit for having 18" wheels. It's a simple checkmark and not an analysis of how cool or light those wheels are. I'd keep your 18s or ask for cash to cover the difference in value. The amount of cash you can get is a point of negotiation.

Unless you have specific performance needs for 17s, I wouldn't waste my time, nor drop the value of my car, to get them. By performance, I mean the desire to run a particular setup. Some tire size combinations are only available in 17s. The same is true for some competition tires. But even then, you probably won't want stock 17s if you're doing track work. You'd want 245/245 for autocrosses and 245/275 for DEs and TTs. That would mean 8.5/8.5 for the former, and 8.5/(9.5-10) for the latter. The factory 17s are 7/8.5. I had a set for autox and ended up running 225/245 b/c that's the best combination I could fit on them. They were Hoosiers so they were still great but the guys that had 245/275 Hoosiers gave me fits.

BTW, the 17s are noticably softer on the street. If your suspension is OEM, that's of questionable value. If you have aftermarket suspension, running soft tires on the street can be nice.

you got that right!

I have 993 18 turbo looks (not the Boxster turbo looks which are a bit narrower). The rears are 10" wide and they are an absolute back-breaker to lift. They look great, but are a harsh ride on street pavement, presumably due to weight and the 30-profile 285 tires. All the more so now with the PSS9s! I use my original stock Boxster 17" wheels (7" and 8.5" wide, 245 and 255 tires) for the track, for all the reasons others have mentioned (weight, tire cost & availability, etc.).

Helpful comments

Sounds like 17" is a softer ride which is what I'm looking for. I commute in the car and drive to Southern CA and want a mellower ride. I like to pull G's with the rubber I got, but got to make a trade off. Ideally I'd have both! Thanks again. -Bill