W126 ('88 420 SEL): insufficient load range for front tires - PeachParts Mercedes-Benz Forum

#1 09-04-2002, 08:33 AM

Question:

My specs call for 205/65/15/94V.

Unfortunately, my tire guy (almost a year ago) put on Michelin Rainforce MX4s on my fronts, rated at 92T. Has a high sidewall, and I've noticed that - with only a B-Temp rating and a T tire and in S. Florida - the sidewalls are flexing too much, the tires (even with 36-37 lbs) seem to run a bit on the sidewalls, and that there are a couple of dimples in the sidewall structure. All this results in extra lean that is temp. sensitive, and a bit of lumpy ride effect in front. Am I imagining things? Will a V-rated tire (which the specs call for) make a huge difference?

MikeTangas · #2 09-04-2002, 10:43 AM

Actually I beleive an H-rated tire is the minimum for your car. That is based on the vehicle weight more so than top speed. An H or V rated tire should be fine.

#3 09-04-2002, 10:47 AM

Mike:

So you agree with me that this tire, in a T-rating, just wouldn't hold up the weight properly for this car?

MikeTangas · #4 09-04-2002, 11:06 AM

A T rated tire most certainly is underrated for a W126. These are heavy cars and they warrant the higher speed rating due to the weight (plus the 560SEL is capable of 140 MPH, I imgaine the 420's can get close to that too).

I would worry about the sidewalls giving out on a T-rated tire. The Tire Rack web site, if you do a search for tires by model, will tell you what the minimum rating for your vehicle is. A nifty feature.

#5 09-04-2002, 11:17 AM

Thanks, Mike.

Ialready put V-rated on my rears a couple of weeks ago - made a big difference, and the profile of the tire is much different as well. This coming weekend, will match them on front, as well.

What are you running on your 560?

MikeTangas · #6 09-04-2002, 11:49 AM

I'm running H rated Avid H-4's with absolutely no problems. Opted for 205/60/15, a little wider and lower profile than stock size, but with almost the same overall dimensions which keeps the speedo correct.

#7 09-04-2002, 12:29 PM

Interestng, Mike.

Just last week, I had to (temporarily) put on my H-rated Yoko spare on the left front. Immediately, the vibration and bounce I encountered at highway speed disappeared. Now I feel that the right side (still the T tire) dips a bit, and is weaker. I'll be happy when my tires are replaced next weekend.

Michael · #8 09-04-2002, 05:56 PM

Tangas is right

Also, I very much like the Michelin Pilot tires...they seem to have characteristics consistent with what our cars like

#9 09-05-2002, 02:03 PM

The T-rated tires may be under-rated for the car, but I wouldn't think they should give you any serious problems in normal driving. When I got my '89 420 SEL it came with Michelin XH4s which are S rated tires. They rode harsh due to the hard rubber compound (they were 80k mile tires) and I wouldn't recommend them for the car. But as far as safety, each tire lists the amount of weight it can hold on the sidewall, and even with weaker sidewalls on S or T rated tires, they should still be driveable. I now have V rated tires and the biggest difference I have noticed is the incredibly rapid tire wear. Maybe H tires would be a good compromise? Of course, if you drive like the road is a rally course, then get V or better!

Todd W126 · #10 09-06-2002, 02:31 PM

I went thru the same thing. A local tire guy recommended some bogus T-rated mess and I went with it. I took them back the next day after doing some additional research ( shoulda done that first I know..duh ). H rated is the minimum you want to use on a 420/560 SEL.

Try a set of Dunlop SP Sport A2's ( H-rated, all season). That's what I ended up going with. Sweet compromise from V rated and a 50K mi tread warranty.

Road noise is almost non existent after first 400 miles. Wet and dry traction are VERY good in addition to predictable feel. They get excellent reviews on www.tirerack.com .