Bad Vibrations - After Excessive High Speeds

[elwesso]

Just remember, before you post, before you hit that little button that says post, just ask yourself "does this post help anyone besides myself?"

[maxnix]

Just remember, before you post, before you hit that little button that says post, just ask yourself "does this post help anyone besides myself?"

I think the PS2 can help any car with the right wheels and a well maintined suspension.

Even yours.

[elwesso]

I agree... are the PS2's quieter than the regular pilot sports, because thepilot sports arent terribly quiet for as many cars (luxury cars) as they come OEM on.

[szh]

The Michelin PS2 is apparently an outstanding tire (although I have no personal experience with it, it seems to be getting rave reviews everywhere).

I have not bought it in the past because it was not sold in a convenient size for my M45. As I recall, recently I did see a 245/45-18 size PS2 at Tire Rack. I was tempted, but the price of the Goodyear Eagle F1 GS-D3 won out (there was a sale on them in July August sometime).

And, I do have very good things to say about the above Eagles!

So, I have a set of four 245/45-18 (in a 100W load index and speed rating, by the way!) of these waiting to be installed - next week probably. Four of them cost me just under $800, including shipping.

[szh]

The PS2 are enormously expensive, but they are a superior tire to the XGTH, especially in the rain.

Given that you have tried both tires, could you please compare PS2 handling (braking, etc.) in the rain to the Firestone SZ90 EP? That was my Gold Standard!

Z

[texasoil]

I recently changed out a set of 3yr old, half worn (depth still 4-6) Michelin Pilot XGTH 235x65 on my wife's 92active. Traction had deteriorated so much is was very tricky to get around a corner on many wet streets-rear end would break loose with any throttle application.

LOVE the new Kuhmo KH-11--ran a set 35K miles on my 94active, down to near wear bar, all were evenly worn across and around, STILL had MORE traction wet and dry than new Michelin XGTH had. IMHO, the Michelins are way over advertised for traction and wear. 2 sets of the Micheline warranty replaced on mileage at 25K, even with remounting and reversing every 10K miles. They used to be better than others, but Others have superceded them now.

[Jesda]

I'm popping in to praise Bridgestone Potenzas.

[DrewQ45]

I ran two sets of Khumos a while back. Great price and decent tires but the sidewalls scare me. If you pinch it between thumb and index fingers, the thinness would make you think Khumo is a spinoff of the Trojan company.

Since I'm still a lover of a great deal l now stick with Sumitomo HTR+. 18" non-directionals mean I don't spend big $$$ changing tires all the time.

[xmateo]

The Conti's are on the car now. Handles great and no more vibrations. I had inspected the Pirelli's just prior to removing them and found one of the tires with a depression in the middle belt(s) in only one area. Scary. Happy to be safe again. Confidently, quietly and smoothly cruise at 95 mph now.

[Q45tech]

a set of 3yr old TIRES.......................well of course since the Q was designed for tires that were done after 18 months at MOST.........remember even the reduced design of the 94-95 had a tire with a max tread wear index of 200 vs the 90-93 with a 170 tire.

A double or triple hard tire will always exhibit these poor wet conditions when aged excessively ...................3 years WOW.

[szh]

I'm popping in to praise Bridgestone Potenzas.

Uh ... which one? That name is generic to a bunch of Bridgestone tires ...

Z

[szh]

I had inspected the Pirelli's just prior to removing them and found one of the tires with a depression in the middle belt(s) in only one area. Scary.

The Conti's are on the car now. Handles great and no more vibrations. Happy to be safe again. Confidently, quietly and smoothly cruise at 95 mph now.

Most Excellent!

Glad to hear this result.

Z

[Q45tech]

Amazing how replacing 4 year old underspeed rated worn out tires will improve the feel of any car..............a modification on the theme "my brand new tires feel so much better than my old worn out tires".

http://www-nrd.nhtsa.dot.gov/vrtc/ca/tires.htm

http://www-nrd.nhtsa.dot.gov/v...s.pdf page/slide 10 shows the exponential increase in tire failure after 2 years in claims per thousand tires.

People buy tires that might be 2 years old brand new then run them 2 years = 4years ALWAYS READ THE DATE CODE as these test were 2 years from manufacture date not 2 years on the car!!!!!!!!

For those that love data here are the latest spreadsheets note hardness and other TABS on Excel:http://www-nrd.nhtsa.dot.gov/v...1.xls

Spend some time reading and looking at the test videos and photos of failures under normal standard conditions..................should scare you plain and simple

[xmateo]

Thanks for mocking me. You'd know had you read all my comments that I was quite pleased with the previous tires until just recently. So regardless of age, the last tires "felt" almost as good as my new tires (save the last week or two)!

[maxnix]

So regardless of age, the last tires "felt" almost as good as my new tires (save the last week or two)!

Feeeelings! Ahhh, Barry had it right.

But what Q45tech is saying is the carcass break down and delamination were occurring the whole time, even when you didn't detect them via your buttometer.

In-specification safety margins are more difficult to "feel" than outright out-of-specification failures. In between is a vast grey area better not traversed.

[Jesda]

Z: Potenza G009

[szh]

Z: Potenza G009

Thanks! I have to go to get my tires changed (putting on the Goodyears I bought a few months ago) but will see if they have these too. Will take a look at the G009 if they have it there.

Z

[szh]

Given that you have tried both tires, could you please compare PS2 handling (braking, etc.) in the rain to the Firestone SZ90 EP? That was my Gold Standard!

Brian (maxnix), could you take a look at this question when you get a moment? Since we are now on the second page, you might have missed it on the first page of this thread ...

Z

[maxnix]

Given that you have tried both tires, could you please compare PS2 handling (braking, etc.) in the rain to the Firestone SZ90 EP? That was my Gold Standard!

Brian (maxnix), could you take a look at this question when you get a moment? Since we are now on the second page, you might have missed it on the first page of this thread ...

Z

Rain, about equal which is a big step up for the Michelin. In the dry, Michelin, but now I have a correctly sized tire as opposed to the one size too small Firestone. Wear rate, about the same, but the Michelin is quieter.

One final note:

Firestones on 16x7 20-slot stock wheels. Load rating 97.

Michelin on 18x9 OZ Superleggera. Load rating 99.

Both wheels weigh about 20 lb. or a tad over.

PS2 is a better tire, but you pay for that marginal increase in performance. Is also directional and asymmetrical.
Modified by maxnix at 9:00 PM 11/23/2006

[xmateo]

Feeeelings! Ahhh, Barry had it right.

But what Q45tech is saying is the carcass break down and delamination were occurring the whole time, even when you didn't detect them via your buttometer.

In-specification safety margins are more difficult to "feel" than outright out-of-specification failures. In between is a vast grey area better not traversed.

Well Dah. I've read that, I don't need it repeated.

[maxnix]

Well Dah. I've read that, I don't need it repeated.

Perhaps, but as evidenced by your post

So regardless of age, the last tires "felt" almost as good as my new tires (save the last week or two)!

some comprehension was lacking.

We were all ignorant about tires (and everything else) at some point. The objective is to learn, not to maintain a state of studied ignorance.

[bullittandy]

Perhaps, but as evidenced by your post

some comprehension was lacking.

We were all ignorant about tires (and everything else) at some point. The objective is to learn, not to maintain a state of studied ignorance.

What your ignorant about is being decent and your intensions are not in any way related to helping others learn. Your posts are meant to insult others so that you feel better about yourself.

Also, the reason that you keep responding to this thread is because you do know alot about tires but you have consistently been quiet when you are called out on your BS. I've had this expereince several times.

[Q45tech]

All I can do is keep on pointing out that Nissan chose the most expensive tire available in the 65/15" size from the manufacture which had the highest reputation for quality and durability as the oem tire for the 90-93 Q. This tire was so soft and had such extreme traction that it wore to the cords in 15,000 miles. "[Comparable to a008 or RE71]" the Michelin Sport XGTV

In 94 they contracted with Dunlop to build a one of a kind tire specifically for the 94 Q [D80V4]. This tire lasted 18-20,000 miles.

First published in Car and Driver in August 1989. 1990 300zx

"The 300ZX storms from 0 to 60 mph in 6.7 f seconds and rips through the quarter- to mile in 15.0 seconds at 93 mph. It e doesn't feel that quick: the engine always sounds smooth and unstrained, even when tearing up to its 7000-rpm redline. ti And the big, solid body (the Z weighs s 3341 pounds) insulates the cabin from ti the furor. In fifth, the engine winds to 6100 rpm-good for 143 mph."......................................"Thanks to clever tuning, this suspension combines stability, control, and a reasonably compliant ride. Shod with 225/5OVR- 16 Michelin Sport XGTV tires mounted on attractive alloy wheels, the Z turned in an outstanding 0.86-g skidpad performance. As you reach the limit the front tires slide first, but the rear end can be coaxed out with a sudden move on or off the throttle, making the Z easy to balance through turns. The fat Michelins offer progressive, predictable handling characteristics, but on some surfaces they howl out enough road noise to scare a Peterbilt pilot.

Beefy four-wheel vented disc brakeswith four-piston front calipers and standard ABS-stop the Z from 70 mph in 171 feet. We observed no signs of fade during repeated hard trials."............................

"The base two-seater wears a $27,300 sticker, and our fully optioned test car carried a $30,160 price tag. "

The 1990 Q45 stickered for $38,000.

Look at the XGTV tread pattern probably different from the tires on every Q today: obviously a dry racing pattern