Tire Life

[BadQ45t]

Is there a generally accepted lifespan for tires. I know this isn't an Infiniti question, but my 84' 300ZX has a set of Bridgeston RE71's that I put on about 5 years ago. They have about 10k miles on them and are about 1/4 tread left. Do they need to be replaced just from a life-span point of view??? I'd hate to have a blow out.

[PalmerWMD]

The answer is a definite yes.

regardless of teh thread left (1/4 being to little anyway I feel) after 2 or 3 years the compound will have deterioted hardned, vulcanized.

Many if not most of the bands inside your tire will be broken at this point even in a quality tire (cheapo tires on a heavy/hi neg camber car like the Q are much worse, less than a year=junk)Our local tire Guru Q45tech has made amny experiments in this area and if he sees this post he will chime in with more detail I am sure.

Fred...

[BadQ45t]

I though this might be the case...I've been trying to figure out an excuse to replace these on my Z anyways since there are so many better ZR and WR rated tires out there for my slot car Z. Since it is a sundy driver and doens't get alot of use I will probably buy the best tires I can afford (Bridgestone SO2 Pole Postions maybe).

Thanks for the quick response!

[greg_atlanta]

I'd be more worried about wet weather performance than a blowout. Old tires get hard, and the harder the tires the worse they perform in rain.

I've got plenty of tread left on my Yokohama AVS dB 225/60/15 -- which I've used for two winters, about 15,000 miles -- and was going to take them off and save them for next winter, but I've decided they're getting too funky and I'll probably throw them away in a few months. They feel great a few weeks after I have them balanced but then get out of balance. Feathering again too.

There aren't many tires you WANT to keep on a car for more than 20,000 miles unless they're generic all-season tires on a generic car.

[BadQ45t]

Well the old Z doen't have to venture out into the rain anymore, it became a sunny day sunday car about 10 years ago...but I've been lusting after those Bridgeston SO3's for a year now, they actually make them in 15" size, but gotta decide if it is time for 17" rims and than buy new rubber.

[VimyJ]

Well the old Z doen't have to venture out into the rain anymore, it became a sunny day sunday car about 10 years ago...but I've been lusting after those Bridgeston SO3's for a year now, they actually make them in 15" size, but gotta decide if it is time for 17" rims and than buy new rubber.

I don't know if you've checked out the siping thread but it could be an interesting experiment on your old tires to have them siped (providing there'e at least 50% of the tread left) and see if that "freshens" them up a bit.

[szh]

Some time back, on my wife's Acura, I noticed after 5 years and 20k miles, that she still had half the tread left. But, there were lots of micro-cracks in the rubber inside the tread area. I did not want to take any risks and bought her new tires that day.

Now, I strongly believe that the life-time of tires is limited too. Tread usage is only relevent if it "ends" (less than 2/32") within a two year period. Like on my Q, where I put on a lot more miles per year!

Z

[shaginator]

Age will dry and crack the tire, especially if they aren't "used" enough. When they're used, the preservatives, oils, whatever get mushed around inside the compound. Assuming daily use, that's usually enough to keep the tire from drying/cracking before the actual treads wear out. I think tire warranties are generally centered around this assumption.

By the way, there's a clearance on Yokohama AVS Intermediates... $39 each. I just ordered a set for our 94 Q; we'll see how they ride.

[AZhitman]

Very true. My dad and I just had this discussion.

215/70/16's (H-rated) on a 2001 Grand Marquis...

For starters, the load rating CAN'T be sufficient for that warthog of a car. Second, he has 52K miles on the car (they travel a lot). Third, the car is used to commute 100 miles a day (in Phoenix heat).

Sooooo, He came for advice on which tires to replace with, and added that he was PISSED that the stockers only lasted 52K... Trying to contain my fury, I steer him towards a +2 upgrade, while remaining in the ballpark of the 40K-mile treadwear warranty AND in his price range. Meanwhile, he's drooling over these goddamn skinny whitewall Michelins with a tread depth of like two inches and an 85K warranty!!! He's 73 years old!!! He'll likely not SEE 85K miles!!!!

And while I'm discouraging this purchase, the basturd behind the counter is ROLLING his eyes at me!!!! I wanted to drag his a$$ out from behind the counter, stand on his scrawny throat and tell him horror stories about load ratings and stopping distances and sidewall strength and slip angles and heat dissipation and UV damage and.... AAAAAUUUGH! Screw it.

So we now have yet another 73-year-old man in a 2-ton luxobarge who still drives like he's 18 and thinks his car can stop on a dime because it has new tires. Yes, Dad's a menace to all Phoenix-area drivers AGAIN.

[BadQ45t]

Wow, is that at Tirerack for $39 bucks each???? That is a non-brainer, but I've always wanted to put the Z on bigger rims (even though my stocker 84's are prestine)....but for 160 bucks to try out the AVS Intermediates might be worth it.

I'm going to examine the tires tonight and see what they look like with a magnifying glass. I'm not complaining about the tires, they still perform very well, I really rarely hear from them and they stick like no tires I've ever had before (they were my first ZR tires).

[greg_atlanta]

Wow, is that at Tirerack for $39 bucks each???? ....for 160 bucks to try out the AVS Intermediates might be worth it.

Very fun tire, perfect for weekend car!! Great in rain too as long as it's not too cold.

I saw a red late 80s Lotus a few years ago and noticed it had the same tires as my car!! (at the time, Yoko AVS Int. 235/60/15 -- that size no longer available)

I have a set of 225/60/15 to put on in the next few months, and might just order my next set as soon as I free up the closet space.

Drive 'em hard, throw 'em away!!

:blue

[shaginator]

Quote »Originally posted by BadQ45tWow, is that at Tirerack for $39 bucks each???? ....for 160 bucks to try out the AVS Intermediates might be worth it.[/quote]Yup $39 each. I ordered a set. You know... now that I think about it I could've ordered 5 instead of 4... I haven't checked that spare lately.

greg_atlanta -- that's everything I've heard about those tires. Fun for weekend zipping, and cheap enough to drive them hard. Should be fun once I'm done installing those Tokico blues (I'll have the plenum done tonight... yee-haw).

[BadQ45t]

I was ready to pull the trigger but the Z takes 225/50 not 60 series. Since I only buy tires for it every 4-5 years I'll probably bite the bullet and score the SO3's.

[deputydriver]

Jeff, The S03s are great tires, but if you're going to spend that much, look at the Michelin Sport Pilots. I recently put a set of 225/50 on my Q and noticed much better wet handling. They also should wear better without giving up much dry performance.

Just a thought. If you spring for the S03s, let me know how you like them.

[maxnix]

Quote »I recently put a set of 225/50 on my Q[/quote]I hope they were in fact 225/60 or else your tires are short and overloaded.

[szh]

I have Firestone SZ50EP's (in a 225/60-15 size) on my Q and am very happy with them! Their wet braking and handling characteristics are superb. It looks like I will get about 20k to 25k miles out of them to get to the 2/32" mark, less if I decide to change them with more tread left.

The price was higher than the Yokohama stuff, but I am completely satisfied with the handling, highway quietness, wet performance, etc. The price is worth it! The Firestone's SZ50EP's are the best tires I have ever used - 7 different cars, 28 yars of driving, an average of 15k miles per year!

On my Q's, I have tried the original Michelin XGTV (OEM) for my 1991 Q, replacement Michelin XGTV (non OEM) and Bridgestone RE940. The Firestone SZ50EP beats them easily!

I will get them again for my Q, as well as for my wife's Acura CL when she needs new tires in a few years.

Z

[diamondj30]

ditto.best tire ive had also.sz5000000000000

[TnQDrvr]

Thanks for reinforcing my decision to go with the Firestones...just returned from having a set of SZ50EP in 225/60-15 installed on my 90 Q. I realize they are brand new, but the difference in the noise level between my old Dunlops and these new Firestones was amazing.

[szh]

Thanks for reinforcing my decision to go with the Firestones...just returned from having a set of SZ50EP in 225/60-15 installed on my 90 Q. I realize they are brand new, but the difference in the noise level between my old Dunlops and these new Firestones was amazing.

You will love the handling too! I am hooked on these tires!

Z

[BadQ45t]

Wow, only think of Firestone as exploding Explorer tires...I've got to make a decision on my Q's new 17" rims that I have waiting to be installed in LA (my cheap *** is waiting for my 16" tires to wear down a little more). Are you running ZR Rubber????

[BadQ45t]

didn't see the other reply above on the Michelin's, those are like 240 something a tire and the Bridgestones are like 160ish, but I'll consider it. Wet handling isn't a priority since the Z is a sunny sunday car, but I do want to get the best tires I can find since I don't replace them too often.

[Q45ver]

Luck of the Irish hit me past weekend. I have been thinking about snow tires for my Q. Not often any snow here but have experienced it once since I've had the car and it wouldn't move. On the weekend a guy drove by then backed up and commented on the mint condition of my car. He then told me he had 4 stock rims for it with snows mounted! I snapped them up! (Michelin's.) My Car still has the original Michelin's that came on it. Earlier comments tell me some think they should be tossed. They have around 30K on them and show around 50% tread, which I attribute to the previous owners sedate driving habits and relatively cool temps here. I'm checking out various owners tire recommendations for possible replacements this year.

[maxnix]

I had the original tires on my Q45t when I purchased it in NYC last spring with only 26K miles. Although I had the Yokohama dBs in NYC, through a series of mishaps, I could not get them mounted in 3 tries on the way back to Seattle, and drove all the on the original Michelins. No vibration or drift at any speed, and about ±7/32nds of tread on all 4.

Microscopic cracks and one ¼" one in one sidewall discovered after I took them off made me feel lucky the carcass was as strong as it was. I was very lucky.

[Chaz98Q45t]

I'm a Michelin man for my cars. I've got the pilots and I absolutely love them. Quiet, smooth ride and handle really well...definitely recommend them. For my motorcycles though, I'm a dunlop guy all the way...

[szh]

Wow, only think of Firestone as exploding Explorer tires...I've got to make a decision on my Q's new 17" rims that I have waiting to be installed in LA (my cheap *** is waiting for my 16" tires to wear down a little more). Are you running ZR Rubber????

The Firestone SZ50EP's are indeed ZR rated! Just awesome tires. I have not used the Yokohama AVS db or AVS Intermediate, so I cannot compare to those. But the SZ50EP is definitely superior to the Michelin XGTV (both OEM original and the later Pilot on Q), Bridgestone RE940 (on Q), Goodyear Eagle RSA (currently on my wife's Acura CL) and Michelin MXV Plus (the last set on Acura CL).

In the past, on other cars, I have used Pirelli P7, Pirelli 6000, Dunlop D60, Bridgestone RE71, Goodyear Eagle GT, and a few other brands/models, and the SZ50EP is far better than all of them. No doubt in my mind!

They stick very well, are super-quiet on the highway, outstanding handling in wet weather (braking and cornering) - which is what I get scared driving in. The only negative comment I might make is that the sidewall seems a bit "flexier" than the Michelin's, but the 225/60-15 is still a 95 rated tire (i.e., able to take the weight of the Q). The slight bit of more flex does not affect the grip at all.

There are sections of curvy rising hill road near my house, speed limit 45 mph, which everybody with sporty cars regularly takes at 60 to 70 when the cops are not around. In my Michelin XGTVs and RE940, I used to take this at 70 to 75. With the SZ50EP, I have driven this at 80 to 85 mph without tire squeal or any sense of danger of sliding and killing myself. Most fun I had was blowing away an Audi TT down the same slopes last month - he backed off at 80+, and I was going over 90 at the bottom of the hill!

Z

[Q45tech]

If you like the EP you should have tried the older discontinued non EP SZ50 with it's 220 tread wear. Unfortunately they lasted 22k at best but Fstone hardened the compound on new EP version to add life..........still a bargain at $115 each in 225/60/15

Not really a winter tire.....no snow or ice allowed!

[TnQDrvr]

I paid $105 at TireRack for the SZ50EP in 225/60-15. Local dealer wanted $160! After paying shipping and installation charges, I still came out way ahead.

[BadQ45t]

They are consideratly more in the size I'm considering for my Q (like 170 bucks a throw) and not available in the 225/50 15 size my Z car needs. I'd have gone for them for sure for the Z since I don't put many miles on her and wanted the very best performance.

I think either the Kumhos or Yokos AVS100 for the Q. 170 bucks a tire is just too much...for 105 it would be a no-brainer.

[PalmerWMD]

Jeff what size are u looking at?

For my 17's I had them in 245/45 ZR17 @ $210 each.Not cheap at all.I was thinking of trying out the Kumho ectsa 712 at half price.

I <did> like the SZ50 EP's a lot tho.

Fred...

[BadQ45t]

Sorry, I'm getting two tire purchases mixed up here. The 17" are for the Q45, and I'm going to do 245/45 17 as well. I'm thinking of the Yoko ES100's for about 100 bucks a tire (a little more the Kumhos, I'm thinking about those too). For my 1984 300ZX, I'm going for 225/50 15 and for those the SO3's are 135 bucks each.

Have you heard anything good about the kumho estsa 712's???