Stock MXX3's, do they stick after 10k miles?

[Mike Brunton]

Stock MXX3\'s, do they stick after 10k miles?

Hi,

I was at the drag strip on Wednesday, and was very disappointed with my performance. The best run was [email protected], but the rest were in the mid-high 12's and the MPH ranged from 114-117. I've dynoed my car at 414RWHP and 465RWTQ (corrected down from 440RWHP and 495RWTQ). It was pretty cold last night, and I could feel my car was making a LOT of power.

The problem is I was spinning all down the track. No traction in 1st, I spun almost all the way through 2nd, and I spun through 1/2 of 3rd. By the time I could get traction, I was hitting 4th and going through the lights. Granted, it was track opening day, and the track was pretty bad, but I was running a couple of 10ths quicker 2 years ago with 5k on the car and tires.

My '98GTS has 21k miles on it, and my rear tires have about 1/3 the original tread. Are these tires good at 21k miles, even with a good amount of tread left?

 

[Tom F&L GoR]

Re: Stock MXX3\'s, do they stick after 10k miles?

I replaced P-Zeros with MXX3s, which after a year are just now at the wear bars. I was very surprised how sensitive the MXX3s were to ambient temperature; those 20F drives to work were more like skating. Now that I'm down to the last month or so of life, I find that they are harder longer; more slippery than I think they should be, even as the local temperatures get into the 50s and 60s.

PS: had a flat in the front (one P-Zero had a stress crack? across the tread and the crack at the shoulder leaked!) so I replaced both with used XGTZs - wow, much better. Actually trying to use up the rear MXX3 faster

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to get XGTZs on the back.

 

[Mike Brunton]

Re: Stock MXX3\'s, do they stick after 10k miles?

Tom,

Thanks for the info - I agree with you 1000%! I really don't like the MXX3's all that much... they seem pretty hard now (were good when new), and they are REALLY bad in cold weather. I'm in Boston, and on a cold day (below 35 deg.) it makes the car almost scary - especially since it makes more power in cold weather.

One of my biggest peeves with the Viper is the TOTAL LACK of tire selection. I can basically only run MXX3's or PZero's... neither of which I really like.

If I could pick, I'd run Yokohama A032R's on it, or G-Force R1's on a daily basis. I don't care about tire life or wet performance, so these would be good for me. If I want any kind of specialty tire, I either need to get different rims, or start swapping front wheels onto the back and run a 315, etc... neither option is particularly appealing to me.

I'm hoping with the new slew of performance cars that are around - most of them using bigger wheels, we might start to see some more selection, but I think the width is what hurts us on the rears - very little market for 335/345 tires

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[Doug Supercharged Vipers]

Re: Stock MXX3\'s, do they stick after 10k miles?

Mike -
The tire age does matter. The miles on the tires are not the only relevant factor.
I find age being one of the "Two Evils." Heat Cycling kills tires. The constant hot/cold cycling makes the tire compound harden and dangerous for street use.
I highly recommend to anyone (especially on sports cars) to bite the bullet and change your tires when traction becomes compromised.

Whenever doing performance upgrades, we recommend a FRESH set of rubber to take advantage of safety and traction.

Best Regards,
Doug

 

[Mike Brunton]

Re: Stock MXX3\'s, do they stick after 10k miles?

Doug,

If anyone should recommend that their customers have fresh tires for maximum traction, it's you! LOL

Thanks for the info...

 

[Bill Pemberton Woodhouse]

Re: Stock MXX3\'s, do they stick after 10k miles?

Mike,
Keep in mind when you get new tires, that the Pilot Sports do not have as stiff a sidewall as the MXX3's had. This gives you more flex on the strip , like you would want, and they seem to be working well for guys at 18-20 lbs in the rear. The MXX3's are superior on the roadcourses ( stiffer sidewall = less sidewall flex ), but they are getting very difficult to find. Call Jon B at the PartsRack (253-475-5945 ) and he can help you out.

 

[Venom Lover]

Re: Stock MXX3\'s, do they stick after 10k miles?

Mike,
MXX3's are notorious for being very sticky for the first few sixteenths of tread, and then nasty and hard thereafter. With your mileage and the amount of launches and burnouts you've done (I'm just guessing on that one

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), it's safe to say your MXX3's are shot. I replaced mine at about 11K miles, and the new ones feel much stickier, though 60' times at the track didn't come down until I put in the 3.55 gear.

With respect to Bill P's comment, he's correct that the Pilot Sports have softer sidewalls. They also have a lower void ratio (more rubber in contact with the road) than MXX3's. However, there is a huge difference in wear rating. I'm working from memory here, but it's like 140 for the MXX3's and 220 for the Pilot Sports. In short, it looks like Michelin compensated for much less sticky rubber on the Pilot Sports by softening the sidewall and decreasing the void ratio. The result is they probably get back to the same off-the-line grip as MXX3's with much less favorable characteristics for cornering, as Bill notes above.

Personally, I like the MXX3's for street and track use, so I stockpiled a few sets, since they are basically unobtainable. Let me know if you're interested, and I can steer you in the direction of two vendors who still have some (last I checked).

Doug,
Can you elaborate a bit on what difference age makes (assuming the tires are stored in a cool dry place)?

 

[SoCal Rebell]

Re: Stock MXX3\'s, do they stick after 10k miles?

Mike I do not agree with Venom Lover (what else is new), I have the Pilots on my 2000 R/T, I just changed to a fresh set after 10,500 even though they still had tread, I figure I will do this every year. Venom and I have identical mods includng the rear end ratio and he even puts out 35 more hp then me but I am about 15/100s quicker in 60 ft. times when we race each other. I assume drivers being equal it must be the tires of which I run the Pilot Sports at 20 psi as opposed to Venom and his MXX3s.

 

[Venom Lover]

Re: Stock MXX3\'s, do they stick after 10k miles?

Hmmmm, that's an interesting point, SoCal, though I always assumed your better short times were due to superior skill.

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Seriously, the only way to know is for me to throw on some Pilot Sports and see what happens. Of course, I won't be doing that until I burn up my current set of MXX3's, but it's probably worth thinking about.

In the mean time, with more practice, if I can get 1.8x short times on my MXX3's, we'll know they're as good as the Pilot Sports.

For sure, though, SoCal, the MXX3's are better for road racing. (Not that Mike B cares about that....)

 

[SEASNAKE]

Re: Stock MXX3\'s, do they stick after 10k miles?

I'm on my 4th set of tires now and I've noticed that after 10 to 12K miles the tires definitely break loose a lot more. 60' times appear .1 to .2 worse at this point. Where I notice it the most is in street driving where you have to be much more careful above 4500 rpm and when it cold or wet. I've wondered if it isn't also related to tire weight as well. Compare the weight of a new MXX to one with 12K miles and there is a substantial difference.

Bill,

If you know anyone interested I have two new fronts (285/40s) and two rears with 3K easy miles (no drag racing or burnouts) on them I'm getting ready to sell.