jbarnhart

I got a good deal from a local fellow on 18-inch S8 wheels -- the 6-spoke version that looks so nice. Trouble is, I'm having second thoughts about the ride quality of the 18-in wheels compared to my current 17-in ones.

My car has Goodyear Eagle LS tires, 225/55/17, on 5-spoke wheels. They are competent, but not exceptional tires. With my sedate driving style, I've never even broken them loose from the pavement.

The 18-in wheels I bought came with 225/40/18 tires -- way too small for my A8. I'll have to invest another $1000 in tires just to see if I like the wheels.

What the heck am I doing? I drive about 6000 miles a year -- mostly road trips to Sacramento and L.A. from the Bay Area. Am I going to love these wheels, or am I going to curse the wheels and wish for my 17's?

greenie

and your new tires are 18s yet to say they are too small? IMO, invest in new tires if thats what it takes. BTW, I believe that you will get used to the ride quality of the new wheel/tire set up. I did the same thing with my RSX, wondering what I had just done after driving over a rough road surface. After a short time, I got used to it and enjoyed the better handling qualities the larger set up exhibited.

ryoung

Three things affect ride -- sidewall height, the brand of tire, and air pressure.

Your 225/55-17 has a 4.9" sidewall height, the 245/45-18 a 4.3" sidewall, and the 225/40-18 a 3.5" sidewall. The last is the same as my ultra-low profile 255/35-20's, and I'm not at all surprised that the ride is very (or too) firm. See <A HREF="http://www.audipages.com/upgrades/tiresizeoptions.html">A8/S8 Tire Options</a> on audipages.

In California, you won't even need all-season tires. Any tire in 245/45-18 will be much better, but give ride comfort a priority in these Tirerack comparisons of <A HREF="http://www.tirerack.com/tires/surveyresults/surveydisplay.jsp?type=MP">Max Performance</a> and <A HREF="http://www.tirerack.com/tires/surveyresults/surveydisplay.jsp?type=UHP">Ultra High Performance</a>.

You didn't mention what tire pressures you're running. You can run as low as the Audi recommendations; I run a bit higher for the improved handling and accept the stiffer ride.

ryoung

Don't compare the survey scores between different performance categories. Each category has different expectations, and a Max performance tire will have a stiffer ride than an Ultra High Performance tire even if they have the same score. Similarly with handling, a Max performance tire will have better handling than an Ultra High performance tire with the same score.

cj750rock

I went to my 18s from the 17s. The ride is firmer but not harsh. Yes, the tires are not cheap but I think they are worth it.

GrA8ful S8

not that harsh with good roads, I love mine on bad roads even!!

Plus the cosmetic difference is exceptional.

Cheers

skiwi

often completely neglected in these discussions, larger, lower profile tyres &amp; rims can often be significantly heavier than the tyres/wheels you replace. this weight is unsprung,and so *will* affect ride quality.

jbarnhart

All you're missing is a clear explanation from me.

I bought the 18-inch wheels from a guy who had them on his A4, hence the 225/40/18 tires on the rims. My A8 requires new rubber to fit these rims: 245/45/18 is OE on the S8. I'm getting cold feet at the purchase of the new tires to add to the new rims to put on the car. I can't really A-B the ride quality until I spring for the new tires and mount 'em up.

GlenC

If you choose to sell, let me know. I might be interested if the price is right. I'm riding 16s right now and can't show my face in public.

greenie

Oh!!