Mercedes-Benz Forum banner

1 - 11 of 11 Posts

·
Registered
GL450, R500 traded, ML350 sold
Joined
·
437 Posts
Discussion Starter #1
Looking at the following tires for my R500. They are both Michelin Latitude HP Tour :

a) 255 55 18 - H rated with 105 load rating
b) 255 55 18 -V rated with 109 load rating

The clerk told me that for the H rated tire (a) they were out of stock and would take a couple of weeks or more to get them. So I decided to go ahead with the V rated tire since the clerk said that there are no major differences other than the fact that the V is constructed with stiffer walls which will translate to better handling, and also the fact that is rated for higher speeds.
I welcomed the extra load rating since my R500 is a heavy beast but I am wondering if there are any drawbacks with 109 vs 105 load index and V rated all season tires as opposed to H rated other than cost? Any differences in behavior in snow/wet road? What are your experiences or thoughts?
 

·
Registered
08 R350, 07 Acura RL, 1989 Honda Shadow VLX600 (10K miles)
Joined
·
785 Posts
Looking at the following tires for my R500. They are both Michelin Latitude HP Tour :

a) 255 55 18 - H rated with 105 load rating
b) 255 55 18 -V rated with 109 load rating

The clerk told me that for the H rated tire (a) they were out of stock and would take a couple of weeks or more to get them. So I decided to go ahead with the V rated tire since the clerk said that there are no major differences other than the fact that the V is constructed with stiffer walls which will translate to better handling, and also the fact that is rated for higher speeds.
I welcomed the extra load rating since my R500 is a heavy beast but I am wondering if there are any drawbacks with 109 vs 105 load index and V rated all season tires as opposed to H rated other than cost? Any differences in behavior in snow/wet road? What are your experiences or thoughts?

In my opinion, both tires are all seasons and you should not have any problem in wet or light snow.

V rated tire has better handling because of stiff walls and has higher heat resistance at higher speed.(Up to 149 MPH)
H rated tire is more comfortable but handling is not good as v rated tire. (Up to 130 MPH)

You can go higher rated tire than OEM Mfr recommend. Lower rated tire is not recommened.
 

·
Registered
GL450, R500 traded, ML350 sold
Joined
·
437 Posts
Discussion Starter #3
Thanks Asian, that was my thinking also. Just wanted to see if I am missing something.
 

·
Registered
'07 GL320CDI
Joined
·
5,111 Posts
Many times when the same model/size tire is offered in both H- and V-speed ratings, the only difference is initial tread depth. To minimize heat buildup at higher speeds, the intitial tread depth is reduced to reduce squirm. Tire speed ratings are all about heat.

IMHO there is NEVER EVER any reason to buy what "the dealer has in stock." "Couple weeks" is pretty silly, too, as you can get tires from Tire Rack in a week at the most, and so can your dealer get tires in that time frame if he makes the effort for you.
 

·
Registered
GL450, R500 traded, ML350 sold
Joined
·
437 Posts
Discussion Starter #5 (Edited)
Many times when the same model/size tire is offered in both H- and V-speed ratings, the only difference is initial tread depth. To minimize heat buildup at higher speeds, the intitial tread depth is reduced to reduce squirm. Tire speed ratings are all about heat.

IMHO there is NEVER EVER any reason to buy what "the dealer has in stock." "Couple weeks" is pretty silly, too, as you can get tires from Tire Rack in a week at the most, and so can your dealer get tires in that time frame if he makes the effort for you.
Good point too. Just to explain, I am not thinking about going with the V rated tires just because the dealer has them available. I could go to another store (or tire rack) and get exactly what I want. All I am saying is that through the conversation I had, I was pointed to that direction and personally I didn't see any drawbacks. If nothing else the handling will be improved with the V tires. I am just wondering if all else will remain the same, such as tread life. According to what you are saying the initial tread depth on V will be slightly reduced, so does that mean that I will get fewer miles from the tires?
 

·
Registered
08 R350, 07 Acura RL, 1989 Honda Shadow VLX600 (10K miles)
Joined
·
785 Posts
Good point too. Just to explain, I am not thinking about going with the V rated tires just because the dealer has them available. I could go to another store (or tire rack) and get exactly what I want. All I am saying is that through the conversation I had, I was pointed to that direction and personally I didn't see any drawbacks. If nothing else the handling will be improved with the V tires. I am just wondering if all else will remain the same, such as tread life. According to what you are saying the initial tread depth on V will be slightly reduced, so does that mean that I will get fewer miles from the tires?

H and V have the same tread wear 440.

Load index for H=2039 Lbs
Load index for V=2271 Lbs.
 

·
Registered
'07 GL320CDI
Joined
·
5,111 Posts
You'll never perceive any "handling improvement."

What you're more likely to perceive is a reduction in fuel economy, as the XL rating and concurrent higher load rating means a heavier tire, and it will require more fuel to move them.

For handling improvement get summer tires instead of all season tires.
 

·
Registered
2006 R350 1999 ML430 2003 Audi Allroad
Joined
·
41 Posts
You'll never perceive any "handling improvement."

What you're more likely to perceive is a reduction in fuel economy, as the XL rating and concurrent higher load rating means a heavier tire, and it will require more fuel to move them.

For handling improvement get summer tires instead of all season tires.
Agree with lkchris on this.

I think the Michelins provide great safety at the expense of tread life. Worth it in our case.
 

·
Registered
GL450, R500 traded, ML350 sold
Joined
·
437 Posts
Discussion Starter #9 (Edited)
You'll never perceive any "handling improvement."

What you're more likely to perceive is a reduction in fuel economy, as the XL rating and concurrent higher load rating means a heavier tire, and it will require more fuel to move them.

For handling improvement get summer tires instead of all season tires.
Stiffer walls = more responsive handling, it's simply physics even though the difference is probably minimal. As far as reduction in fuel economy, that is also minimal since each XL rated tire weighs a couple extra pounds than medium load rating. I carry around 2 child seats that probably weigh more than that difference and 90% of the time the kids aren't in the car.

I do know that I can improve handling by buying summer tires. Guess what, I can improve handling by buying a sports car also!

What I am exploring here is why does MB use medium load rating tires on a car that weighs 6 thousand pounds without any cargo and passengers. BMW uses XL load rated tires on the X6... which weighs 5 thousand pounds and does not have the room for too much load (does not have 3 rows of seating nor it has a large cargo area at all for potentially carrying a large load). Also, BMW uses V rated tires on most of their products, whereas MB uses H rated. Is it simply that MB is more conservative, or are the differences extremely small and they don't bother?
 

·
Registered
'07 GL320CDI
Joined
·
5,111 Posts
Back in the 1970s all the 450SLs and the S-class cars all came to the USA with V-rated tires.

The majority of the owners of these fitted Sears Roadhandler whitewalls as replacements, this being right in line with the white belt, leisure suit behaviour of the time. Those tires, of course, were likely not even capable of being speed-rated S. The Michelin XWX back then was $150 for heaven's sake, and Sears told these owners they had $75 tires for sale. (maybe cheaper)

Having learned from this, these days, Mercedes now electronically speed limits its USA models (except AMG, etc.) to 130 mph, i.e. the number for H-rated tires, and today it's a LOT more likely owners will fit at least as capable tires for replacements.

As for BMW, their whole existence is based on the perception they are "performance" cars, and fitting H-rated tires would probably detract from that. In reality, there's little that impresses in comparison to Mercedes.

And as for a vehicle's load rating, this is NOT solely determined by tires, and fitting higher load-rated tires does NOT change the vehicle's GVWR.

There's zero/zip/nada reason to expect Mercedes has underspecified tires on any of its USA vehicles and also zero/zip/nada chance any Mercedes owner can "upgrade" his/her car by fitting something besides specified tires.

Don't confuse high performance with better, because they do NOT go hand in hand. And for sure don't think V-rated ALWAYS means "stiffer sidewalls" or "better handling." It just means won't delaminate up to 149 mph. You are simply not going to increase a vehicle's "performance" by fitting tires that weigh more than those specified for that vehicle.
 

·
Registered
GL450, R500 traded, ML350 sold
Joined
·
437 Posts
Discussion Starter #11 (Edited)
I agree with what you are saying. Unless you drive on the autobahn with no limiter and want to go over 130 mph or so you really aren't getting anything for V rated tires.

With regards to load rating, I am not trying to increase GVWR. I never said that. I am wondering why other cars with even lesser weight use XL load rating. Another example is Porsche Cayenne. It is a valid question that can't be dismissed by a simple answer that there is no evidence that MB underestimated the size. I am not saying they undercalculated anything. I am wondering why they went that route.

And last, you make it sound like "you should never mess with perfection". If that was so then all the tuners (Brabus and the like) would not be around.

Thanks for all the feedback.
 
1 - 11 of 11 Posts
Top