On the advice and experience of others in this great forum I replaced my stock Goodyears at 40,300 miles with up-sized Michelin Pilot Sport A/S tires in the 245/50-17 size.

I placed my order with The Tire Rack at $218 apiece plus $30 shipping and figured that my local place would charge $15/tire for mount and balance and then $65 for an alignment. This totals out at $1027.

Just for giggles I decided to call some local places after I had already ordered the tires with Tire Rack. One non-chain Michelin retailer quoted a out-of-line price of $220.34 before mount and balance but they couldn't get the tires for 2 weeks. Other local retailers told me that this quote "had to be a mistake."

We have a local chain called Mr. Tire that does lots of crazy advertising with price matching and a "total tire price" including mounting, balancing, stems, and old tire disposal. At first they told me that the price was a mistake and that even a written quote would have to be validated before they would price match. I said to forget it and that I would just get my tires online. This triggered a page to the store manager who authorized a Mr. Tire inclusive price of $220.34. Cool!

Since they could get the tires to their store in about 2 hours using a shuttle, I canceled with Tire Rack and made my appointment for yesterday afternoon with Mr. Tire. I ended up leaving Mr. Tire $987 lighter with a newly treaded, perfectly aligned allroad. And I even get the free rolling suitcase and the 2002 travel Atlas from Michelin - woo hoo.

I can't post impressions yet because the tires are too green. New tires need a hundred miles or so to shake off that greasy new tire feeling.


See my pics...
40,300 miles on the stock Goodyears:
<img src="http://mywebpages.comcast.net/ryanjen1/old_tire.jpg">

The new 245/50-17 Michelin Pilot Sport A/S
<img src="http://mywebpages.comcast.net/ryanjen1/new_tread.jpg">

<img src="http://mywebpages.comcast.net/ryanjen1/new_sidewall.jpg">

Sitting on new shoes:
<img src="http://mywebpages.comcast.net/ryanjen1/car_with_tires.jpg">

Looking forward to the road test follow up. Any chance you'll be getting them into snow this winter?

My 2003 allroad is not yet here, and already I have been planning on making a few changes to the basic package. Chip, bypass valves, Y pipes, and tires and/or wheels and tires.

I read the allroad project article which discussed plus sizing to 245 x 45 x 18 -- I read the article in Car and Driver that IMO said going to tires with less than a 50 profile (for everyday street use) was inviting "issues" (comfort, wheel, tire damage, cost, longentivity, etc.)

I currently have 255 x 40 x 17's on my A6 4.2 -- I love the wide tire but when I have driven a loaner 2.7T with tires of a higer profile, I must admit the ride is more supple and in day in day out driving, I would have little to complain about.

My point and/or question is: why did you stay with a 17 wheel size? Is it because (money nothwithstanding) there was no "contact patch" advantage to going to a 245 x 45 x 18 over a 245 x 50 x 17 (I have not looked at the error margin, but I assume that the 17's are within tolerance for "circumference" even if they are slightly less "tolerant" than the 18's circumference).

It would seem that the 17's @ 50 series compared to the 18's @ 45 series would have an identical contact patch but a more supple ride. In other words on the Interstates that surround Cincinnati, I would have the benefits of a greater contact patch and the benefits (in ride) of a 50 series tire over a 45 series.

Now, this is not an appearance question, I would say that my tastes would lead me to an 18" wheel/tire package if my decision were to be entirely cosmetic.

My query is more to the substantive differences between [theoretically] identical tires of size 245 x 45 x 18 versus 245 x 50 x 17. What would be the typical differences that could be noticed.

I do not plan "off roading," we have moderate amounts of snow here in Southern Ohio (and even when it does snow it rarely accumulates on the Interstates and primary roads), while I do, when conditions safely permit, drive at fairly high speeds -- even reaching triple digits from time to time, I do like to enjoy the "snake in a rat hole" feeling on twisty roads too (but, alas this is increasingly difficult as traffic and suburban sprawl are eating away at this guilty pleasure).

So, practically speaking -- what is the value of plus 1 sizing when apparently plus 0 will accomplish the increased contact patch and probably have minimal impact on "ride quality"?

Now, I know that the Pilot is NOT available in both 245x45x18 &amp; 245x50x17, so I guess I would have to grant you the liscense to speculate "as if" I could get identical tires in these two sizes.

Thanks for your response.

Mark

If you want the best out of the tire performance wise. An 8" or 8 1/2" rim would probably be a better choice even if you want to stay with 17's. Just my .02.........

Given equal tire constructions, the +1 sized wheel/tire combo increases steering response and feedback, while stiffening the ride.

Load bearing is reduced, and the bigger wheels/tires cost significantly more money.

that rims from 7" to 8.5" are appropriate for this size tire, and they use the 7.5" rim for their example "section width".

I see why you'd think a wider rim would be better, but people seem to have had no troubles with this application. I hope it's ok, since I'd want to put these tires on too =).<ul><li><a href="http://michelinman.com/assets/pdfs/doc_pilotsportas.pdf">http://michelinman.com/assets/pdfs/doc_pilotsportas.pdf</a</li></ul>

Thanks for that information!

but a wider rim would increase the contact patch and improve performance. I am nitpicking I'm sure and the advantage would be small and I suppose if performance was that big a deal you wouldn't be considering an all season tire.

Hopefully the 245 on the 7.5" wide rim works better than a 190 does on a 5.5" 9x6 rim =)

Hmmm. Lots of interesting questions. I am by no means an expert, but I do know that almost any choice like this boils down to a compromise. The lower aspect ratio (45 vs 50) means a shorter AND STIFFER sidewall. The stiffness gives the car better handling/lateral response with an associated ride quality penalty. There is also less air space b/w road and rim when you hit a sharp pothole or other object.

I would say that 50 series is getting pretty low for a cruising biased car, but the particular tire chosen has a huge effect as well. An Ultra High Performance tire is going to be stiffer than an all-season tire.

My choice was based on my opinion is that the allroad is a compromise vehicle - probably the best compromise on the market between luxury, cruising, performance, and off-road ability. I do go offroad and I do use all available road performance when the opportunity presents itself.

In my mind, investing $2000-3000 dollars in a 18" high performance package to bias the car more toward road performance is still not going to get me a sports car and I'll still have to invest another $500-800 for a set of winter tires. For that kind of money I could buy 4 sets of the Toyo T1-S tires that I love to run on my Corrado with 10x the fun-handling factor.

With big expensive wheels I will have lost the ability to randomly go offroad and will give up some of the mile eating ride quality that makes the car so enjoyable for road trips.

I chose a compromise tire for a compromise vehicle. I guess I could have stayed with the stock size, but since the wheels do support a slightly larger tire and Michelin happens to make a good tire that is appropriate in 245/50-17 I just went for it based on other recommendations.

In your case it sounds like you are more interested in high performance and road use only. It may make more sense for you to get a set of 18's. Many folks here have been talking very highly of the Bridgestone S-03s. Give 'em a look.

Thank you for visiting our Web site and sending us your e-mail.

To achieve the best balance between ride, handling and treadwear, select a rim
width in the middle of the manufacturer's range.

To improve cornering traction and steering response, choose a rim at or near the
maximum recommended width. The wider the rim width, the straighter the sidewall
and the quicker the steering response. Conversely, using a rim width at the low
end of the range will cause the tire to balloon or curve out, slowing steering
response.

If you have additional questions, you may call us at 1-800-847- 3435 (toll-free)
between 8:30AM and 6:00PM Eastern Time Monday through Friday to allow one of our
Consumer Relations Representatives to assist you.

Michelin North America
Consumer Relations Department

I figured that the combination of the 17" diameter and the 7.5" width will bias this application towards ride quality &amp; load bearing -- and away from steering response. But, I still hope it's an improvement over the stock Pirellis' turn in response. They feel a bit mushy.

Now that I have a couple hundred miles on the new Michelins the mold release 'stuff' is gone and the tires are broken in. This is a vast improvement over the stock goodyears in turn-in, ultimate grip, noise, and stability. The wider tires make the steering slightly heavier (relay already gone) and make the car feel more stable at speed with a more solid and commanding connection to the road. Gone is the low speed squealing from the stock tires. These handle the heft of the car fairly well in cornering though you can tell it is not a performance tire. I sense some sidewall flexing/rolling which is accompanied of course by body roll thus further rolling the tire over onto the sidewall.

I agree completely with Michelin's assessment. Wider wheels would be better, but staying with stock wheels and choosing between stock size and 245-50's I would do the 245's.

Once again. this is not a performance tire and not a performance car. This tire is a great compromise for me and I suspect others will be equally pleased compared to stock goodyears or pirellis.