HTRZ II pressure? - PeachParts Mercedes-Benz Forum

czwbkx · #1 11-10-2002, 02:23 PM

I am running HTRZ II tires from Tire Rack on my 92 400E in size 205/50ZR17. They are extremely noisy! Various posts, both here on the forum and in the reviews on the Tire Rack site have noted that these tires are very quiet. So what am I doing wrong? My tires sound so bad that I thought I had bad bearings or my brake pads were worn to metal-on-metal!

The only thing I can think of is that I am running these tires at the MB factory specified tire pressures and therefore the tires may be rolling on the outside edges where the ribs are making a lot of noise. Should these be running at higher pressures?

czwbkx · #2 11-12-2002, 07:56 PM

C'mon, buddy. What's the correct air pressure for these tires? Should it be higher than the factory 15"s? The sidewall specifies a max of 45, but the correct number must be somewhere in between.

#3 11-13-2002, 11:48 AM

The tire pressure in the door jamb and on the fuel door is MINIMUM pressure. I expect that adding some would quieten them a little unless they have run many miles already.

Additionally low tire pressure will cause the tire to scrub in the middle and wear them out prematurely.

Hope this helps,

Jim's500E · #4 11-22-2002, 08:35 AM

I have them in 245/17s on my 500E...running at 32 psi and have no noise issues to complain of...so much quieter than my previous Toyos in fact. You sure you mounted the rotation on the tread correct?

czwbkx · #5 11-22-2002, 12:22 PM

Jim,

Thanks for your note; yes, I do have the rotation correct. I run at the pressures listed under the filler cap, though, and that's quite a bit less than you are running at 32#. I have the winter tires and wheels on now, but just as an experiment I may remount the Sumis and inflate to 32# to see if it makes a difference. Four to six pounds could make quite a difference in contact patch, expecially on a 50 profile.

Do you get flat spots after parking overnight? I get some serious "thump-thump" after the car has sat for as little as 24 hours.

Jim's500E · #6 11-22-2002, 04:20 PM

I do get the flat spots...the car sits for days at a time and since its a bit portly I'm not surprised...but they go away after a while....so far.

I only have maybe 2-3000 miles on mine. Never noticed them getting noisier on my old 92' 190E 2.6 which had maybe 12,000 miles on them from new and they were a 40 series set...(?)