Michelin Pilot Sport A/S Plus

[rek]

On July 1 my "Winter Beater" ('06 STS4) got some new shoes. Mr. Tire is my vendor of choice. They use the Hunter system and have a 30 day "No Questions Asked" return policy.

I had the 235/50ZR17 MPS A/S + mounted on NEW 4610 RPO N93 rims. The highest RFB was .014, the others were lower, .008-.010. Not too bad for "Freshly" mounted tires considering the tires weren't "Road Married" yet to the wheels. In two weeks I'll return, after the tires have settled in for another RFB session. Self Stick weights were used. The tires proudly display MADE IN USA on the side walls! They have a 45K mile warranty.

The OEM Michelins (RPO QKP) Energy series (S Rated) were OK but they don't hold a candle to the Pilot Sports. The STS4 now handles like a Go-Kart. Like it's on rails. Steering response in NOW. The Sports are quiet and smooth. $913.68 out the door plus a $70.00 rebate (MasterCard Gift card).

I'm thinking of getting another set of Sports for my '06 DTS to replace the OEM Conti's. It will by a while as they have only 32K miles on them.

[Texas Jim]

Glad you like the new Pilots.

Those are very good numbers...

I just put a new set of Yokohamas on my 06 DTS.

[Cadillac Jim]

I had a set of Michelin Pilot Sport A/S tires on my 1997 ETC and agree that these are outstanding tires for handling. On my car, the size is 225/60-R16, not the 50% profile tires on 17-inch rims you have. On my car, the speedometer agreed with the GPS for speed so the rolling radius was essentially exactly right and the same as the OEM Goodyear RS-A tires of the same size. I found these tires hard as a rock, although I did keep them at 32 psi rather than the 30 psi recommended on the door jamb.

Now I'm running Bridgestone Potenza Pole Position tires of the same rated size, 225/60-R16. The ride is better and the handling is very close to the Pilots, but the speedometer vs. the GPS tells me, with some calculation, that these tires are actually 55% profile, not 60%. It's some years off, but my next set of tires will likely be on 17-inch wheels.

[JohnnyG]

The highest RFB was .014, the others were lower, .008-.010. Not too bad for "Freshly" mounted tires considering the tires weren't "Road Married" yet to the wheels.

Road force numbers are usually expressed in pounds, like 10 lbs; 12 lbs; etc. Maybe you were reading the radial runout of the tires or rims. The Hunter machine has a built in rejection number of 25 pounds of road force. On your '97 ETC, you will likely be able to feel 15 pounds of road force, so the machine settings are much too high for this car. The Hunter machine also has a process built in for seating the beads, so I don't think you need to worry about the tires being fully married to the rims. The old version Hunter RFB machine was the 9700, the new version has automatic air pressure adjustment (critical for proper RFB), and a laser beam pointer to indicate the exact location to install the weights. The stick on weights are only proper for the outside of the rim, if the machine calls for inside rim weight, normal clip on type weights should be used.

One thing you must do before you go back for a recheck, is to make sure your tires are fully warm, and not left to sit for more than about a half hour if the temperature is below 50°F. Tires can be warmed up by driving for about 20 minutes, speed is not real critical in this process. This will prevent the tires from giving false readings due to flat spotting. The Michelins are not real prone to this, but since you are trying to do it right, it pays to know the small details.

[JohnnyG]

BTW, IF those are actual RFB numbers, and the highest reading was 14 pounds, you have an EXCELLENT set of Michelins!

Jims 97, here's something you might find useful: http://www.1010tires.com/TireSizeCalculator.asp?action=submit&reset=yes

[Cadillac Jim]

JohnnyG: They guy with the new tires is rek. I've never had a problem with shimmy or bounce myself. Yet.

[rek]

"The Hunter machine also has a process built in for seating the beads, so I don't think you need to worry about the tires being fully married to the rims."

Mr. Tire did mention the "built in process for seating the beads" but advised the "process" was a "good" start...As per the tire tech, "Real World driving forces exceed the machine's ability to seat the tires. The machine doesn't heat the tires, as driving will. Call when you are ready for RFB #2, and I'll hold a bay open. Drive the car for at least a half hour before you come in. When you come in, drive right into the bay that will be open, and we'll put her in the air right away."

"The stick on weights are only proper for the outside of the rim..." The "Self Stick weights" were "stuck" on the inside of the rim, as done by GM on my '06 DTS. I did talk weights with the tire tech, and we shared the loquacious nonsense " If it's good enough for the GENERAL... it's the way to go...

At any rate, thanks guys for the input.

[JohnnyG]

JohnnyG: They guy with the new tires is rek. I've never had a problem with shimmy or bounce myself. Yet.

Yes, I know Jim, the link takes you to a tire size calculator which tells you what your speedometer error would be if you change tire sizes. It also warns you to stay within 3% of the speedometer error for some reason.

Anyway rek, it sounds like you are dealing with somebody that knows how to get tires correct using the Hunter machine. Hard to find several years ago! Glad to here that you are being taken care of professionally and honestly. My '08 DTS uses regular weights on the inside of the rim and stick on on the outside, which is not really the outside, but as close as possible to it.

[Cadillac Jim]

The Potenza Pole Positions are the OEM size, 225/60-R16. If I didn't have a GPS I wouldn't know the difference. But I do, and I know that with the Michelin Pilot Sport A/S tires the GPS and the speedometer were a match within 1 mph to 80 mph, but with the Bridgestones the speedometer reads a mph or so high at 70 mph. I wrote the numbers down one day and computed my actual tire size as 225/55-R16 no matter what it says on the tire. But the tires handle as well as the Pilot Sports and aren't as hard. They seem to actually hold a little bit better; after all, I didn't buy them in the same year.

Note that rek's new tires are Pilot Sport A/S Plus tires, so Michelin distinguishes the current design from the tires I was using.