e-man

Hey guys. I did a few searches and couldn't find anything right on point. I have a little knowledge about this subject, but, as they say, a little knowledge can be a dangerous thing. I know that a z rated tire is rated a higher speed than a v rated tire (I believe z is 168+ and v is 149+), but that's the extent of my knowledge. What other differences are there (assuming, of course, you're comparing the same brand and model)? Is there any difference in terms of tread life, ride comfort, quietness, etc.? My instincts tell me that a z rated tire is softer than a v rated tire, which should mean that it will have a shorter tread life, but will ride smoother and quieter, but that's just a guess and I really don't know for sure.

Does anyone have any information about this? Thanks in advance.

e-man

rominl

iTrader: (4)

*usually*, z rated tires have softer compound for better grip coz' they are higher performance tires, so they have less tread life than the v rated tires. and in general z rated tires might be noiser again due to the aggressive pattern, though i have seen tons of exceptions

TRoyals14

tread life, ride comfort and quietness will all vary with the tire you pick within the respective speed rating
however, like rominl said, z will usually be your lowest treadwear, although every rule has an exception
the speed ratings don't include quietness or ride comfort, just grip
and i don't think treadwear affects quiteness or comfort at all, those are due to the size of your sidewall and your tread pattern mainly
i wish i could go fast enough to require a z-rated tire

e-man

Okay. Let's assume this. You have two tires, side by side, and they are absolutely identical in terms of brand, model and size. The only difference between the two tires is that one is v rated and the other is z rated. Will one ride softer or quieter than the other? Does it depend on the brand? In other words, are there some brands where a z rated tire will ride softer and quieter than an identical tire in a v rating? Are there other brands where it's the other way around? Are there some brands where there is no difference from v to z in terms of quiet and comfort? Am I making sense here?

e-man

Hey mods. I posted this up the other day over in the tire forum, and haven't gotten much of a response. Could you please leave this up here for a little while?

Hey guys. I did a few searches and couldn't find anything right on point. I have a little knowledge about this subject, but, as they say, a little knowledge can be a dangerous thing. I know that a z rated tire is rated for a higher speed than a v rated tire (I believe z is 168+ and v is 149+), but that's the extent of my knowledge. What other differences are there (assuming, of course, you're comparing the same brand, model and size)? Is there any difference in terms of tread life, ride comfort, quietness, etc.? My instincts tell me that a z rated tire is softer than a v rated tire, which should mean that it will have a shorter tread life, but will also ride smoother and quieter, but that's just a guess and I really don't know for sure.

Does anyone have any information about this? Thanks in advance.

e-man

salimshah

In general your hunches are ALL correct. There may be exceptions but then you would need side by side comparo.

To drive within posted limits V are as good as Z and in general cheaper.

Salim

SRK

The Z rated will tend to have a shorter tread life due to softer rubber compound, but to reduce heat build-up, which is what the speed rating is all about, the sidewalls tend to be stiffer, and the result is a noisier and harsher ride.
On a previous car I owned this was brought out dramatically - I switched from a Michelin Pilot XGT-Z4 to a Pilot XGT-H4 and the ride was amazing, quiet and smooth. Didn't handle quite as well, and I can't say what the speed rating did as I never cruised fast enough to warrant the H's let alone the Z's. H goes to 139 I think?

e-man

Very interesting. So, SRK, in your experience, generally speaking, an H rated tire will ride smoother and quieter than a Z rated tire (assuming same make, model and size), and you're basically giving up some performance going with the lower rated tire.

IAGS400

If you could buy the exact same tire in H and Z then yes I believe it would be quieter. But you would be giving up some traction and turning ability. I will be putting on a V rated tire next spring.

GWELEX

A real quick search found this link from a manufacturer:

http://www.kumhousa.com/Care/TireRSG.asp#sr

Sounds like higher speed ratings do suffer in ride quality.

SRK

Generally speaking the stiffer the sidewall, the better the performance, although there are many variables. So the Z rated should turn in and steer better, and handle somewhat better than an H rated.
I have H on my LS, and Z on my GS400. I will probably go back to a V rated on the LS when the time comes, although the H's certainly ride nicely. I just want to sharpen up the steering a bit on that old boat.

DASHOCKER

iTrader: (2)

I have falken ziex 512 on my 17's. It is a Z rated all season tire that actually rides very smooth and quiet compared to the V rated Michelins I had on before.

TRoyals14

your v-rated might ride quieter, because its tread won't be so crazy
it's very debatable
this assumes that they have equal sidewalls though