OSU_Acura_Guy

Noob question here.

Having some warranty work done on my car by CarMax. I noticed a slight, occasional vibration in the steering wheel around 75-80 mph. Took my car ('07 Base TL, 55k miles) into CarMax to address and they said it was that two tires had been worn unevenly which was causing the vibration. The service adviser told me they would be replacing those two tires with new tires. She also commented that these two new tires had a higher speed rating than my previous tires "which is good." I am not a car expert, but having 2 sets of tires with different speed ratings didn't seem right to me. Plus, I believe I have the same model tires as what comes stock (Bridgestone Potenza RE030) which I think are z-rated. I thought z-rated tires were the highest you could go until you got into the ultra high-performance w and y-rated (which I am assuming they wouldn't put on my car)???

My main question: is it OK to have 2 sets of tires with different speed ratings? My local mechanic advised against that. I have a message in to get the details of the old tires vs. new tires (model, rating, etc).

In the meantime, any input would be greatly appreciated! THANKS!

Bearcat94

"Z" is a general rating, meaning good at 149 mph and beyond. BUT "Z" doesn't say how far beyond. In other words, "Z" is higher than "V" (up to 149 mph), but "Z" is non-specific. More here:

http://www.tirerack.com/tires/tirete....jsp?techid=35



Not sure about 2 differnt speed ratings. Hopefully someone with more knowledge will comment. More reference here:

http://www.tirerack.com/tires/tirete...jsp?techid=136

Will Y.

You should be fine as long as the tires on each end have the same speed rating.

The RE030 was the "summer tire" option for the TL, IIRC.
The standard TL tires were Ultra-High Performance W-rated all-season tires: either Michelin MXM4s(Navi and Type-S) or Bridgestone EL42s(non-Navi).

Welcome to AZ.

Bearcat94

Just to nit-pick, but neither of those were "ultra high performance" category tires. They were "Touring" (EL42) or "Grand Touring" (MXM4).

Turbonut

iTrader: (1)

They can say it better than I can:
http://www.tirerack.com/tires/tirete...jsp?techid=136

I wouldn't mix the tires. Have them purchase the 030's as replacements. Even tires within the same speed rating class can have different handling characteristics, like the DWS, the tire can be bent almost in half, but the Yoko S.4, the tread can barely be moved inward and both are W rated and will handle deifferently.

Also remember that the 030's are summer only tires and shouldn't be drive when the temps are near freezing, so if you feel you'll encounter this scenario in the future, have them supply you some excellent all season tires and then you'll be able to match them up and have a new set. See if you can make a deal with them, unless you want summer tires.

Jesstzn

I'm with him .. I wouldn't mix anything. BTW are they going to fix the reason they were wearing uneven?

Will Y.

OK-- I think I see the issue.
The RE030 for the TL is a W-speed rated tire-- but it is sized as "235/45ZR17," which used to be the convention for identifying a Z-rated tire.
If you're getting new RE030s, they will be the same as your existing tires, with the same speed rating.
Well, at least they were W-speed rated.

OSU_Acura_Guy

All, thanks for the outstanding feedback. For some reason when I did my research before buying I was certain that the Potenza RE030 was the all season tire. Fortunately (minus the 28 inches of snow in the 1st two weeks of February) we don't typically get too much freezing stuff here in Oklahoma at least not enough to worry me about having summer perf tires.

Fortunately when I called the service advisor back at CarMax to tell her that i wasn't going to let them put tires w/different speed ratings on my car she realized that she had given me bad info. Apparently the load rating is higher on the new tires, not the speed rating. After calling my mechanic he said that shouldn't be a problem. Thoughts?

I am going to talk to them tomorrow about that.

Turbonut

iTrader: (1)

Ask them for the make and model tire that they plan on installing and then post their reply as I'm certain we'll have feedback available.

Just a word of caution, don't overestimate the summer tires in cold weather. The rubber becomes very hard and a great amount of taction is lost when the temps dip into the 30's. Also, the 030's are no longer in production and they have only a 140 wear rating. Although not an industry standard, the 140 rating will wear out very, very, quickly. As they are OE style tires, their height is taller than the normal 235/45-17 as they are 25.6" compared to aftermarket 235/45-17 tires at 25.3" when new. More than just load rating to digest. They probably are going aftermarket, meaning non OE, so get 4 245/45-17 tires of your, or their choice, then you'll have a matched set, load rating, speed rating, tread and carcass design.

Armed with this amo, make a wise choice.

nfnsquared

Your bigger issue is why did the tires wear unevenly? If you don't get that fixed, new tires aren't going to help for long. Which tires were they?

You probably need to have the alignment checked.

And I wouldn't be comfortable without a matching set of 4 tires. I'd push them hard to get you a new set for all 4 corners.

OSU_Acura_Guy

OK. Been talking with CarMax this morning. The reason they switched out 2 tires was that one was defective (right rear). So rather than just replace one tire, they chose a second tire that had the most wear (right front) so they could put two on at the same time. So hopefully that answers the question of why the tires needed replaced.

Also, he called and gave me the information of both sets of tires (2 new and 2 old):

Two new tires:
Riken Raptor 235/45ZR17 97W

Two old tires:
Bridgestone Potenza 235/45R17 93W

Doesn't the 'z' indicate that the Riken tires have a z speed rating? What is the speed rating on the Bridgestone's? Are these tires going to be OK together?

Finally, since my TL is front wheel drive shouldn't the new tires go on front?

Thanks so much for everyone's feedback.

Bearcat94

Never heard of "Rikon Raptor" but they are low cost (I won't say "cheap" because I don't know the brand). The Riken are about $100 a peice.





It's the service description "93W" that tells you they have the same load index (93) and speed rating (W). W is the OE rating and good to 168 mph (iirc).

I hate cars

Ideally you want all 4 to be the same. If that's not possible, make sure the similar tires are on the same axle. While I wouldn't mix front to rear, its not the end of the world. The TL has 65% of its weight on the front, they don't use a higher load rated tire on the front vs the rear.

The more important point is that the tire with the lowest rating still meets the minimum requirements.

You need to find out if the original was actually defective or if it was worn unevenly.