Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Mercedes-Benz Wheels & Tires

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-31-2004, 08:12 AM
Registered User
 
Join Date: Aug 2003
Location: MA
Posts: 764
different max pressure

According to the owner's manual, my car need 195 65 15 91H.

I saw load index and max pressure and wonder whether I have wrong tires on my car.

My car seems to have been tested with max pressure 44 psi and load index 91 tires.
If I have max pressure 51 psi and load index 91 tires and keep the manufacturer recommended tire pressure (27 psi for normal load, 28 front 33 rear at full load), effective (not the tire's maximum at the tire's max pressure) load capacity will be smaller?



The original factory installed Pirelli 195/65 15 91H:
Max pressure: 44 psi
Load index: 91

ContiTouringContact CH95 195/65 15 91H SL (on the MB recommended tire list for my car):
Max pressure: 44 psi
Load index: 91

ContiTouringContact CH95 195/65 15 91H SL BMW
Max pressure: 51 psi
Load index: 91

Michelin MXV4 plus 195/65-15 91H SL (currently on my car)
Max pressure: 51 psi
Load index: 91

__________________
1992 300D 2.5 turbo diesel. 319 k miles.
124.128 chassis, 602.962 engine, 722.418 tranny.

Last edited by ktlimq; 08-31-2004 at 08:19 AM.
Reply With Quote
  #2  
Old 08-31-2004, 09:37 AM
Registered User
 
Join Date: Feb 2004
Location: Ontario, Canada
Posts: 491
Maybe Luke from the Tire Rack can confirm, but in my experience, the max. pressure rating varies a lot from one tire design and/or manufacturer to another. It has no direct bearing on the load capacity provided the stated maximum tire pressure is greater than the maximum pressure recommended by the vehicle manufacturer.
__________________
1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown
Reply With Quote
  #3  
Old 08-31-2004, 05:16 PM
Moderator and Tire God
 
Join Date: Feb 2000
Posts: 2,091
Quote:
Originally Posted by Dervman
Maybe Luke from the Tire Rack can confirm, but in my experience, the max. pressure rating varies a lot from one tire design and/or manufacturer to another. It has no direct bearing on the load capacity provided the stated maximum tire pressure is greater than the maximum pressure recommended by the vehicle manufacturer.

good answer which is factually correct but, missses out on the most important part of air pressure vs. load capacity

A P-Metric tires max load is achieved at 35 psi and a Euro metric tires max load is achieved at 36 psi adding more air pressure will not increase the tires load capacity but, lowering it will reduce the load carrying ablility. When increasing pressure all you are accomplishing is a lower rolling resistance, quicker steering response, stiffer ride and contact patch reduction.
__________________

Please, call me to place orders or for more info
use my name for on-line orders
Reply With Quote
  #4  
Old 08-31-2004, 06:50 PM
Registered User
 
Join Date: Feb 2004
Location: Ontario, Canada
Posts: 491
Quote:
Originally Posted by Luke@tirerack
adding more air pressure will not increase the tires load capacity
While I don't dispute your answer, I'm curious as to why most vehicle manufacturers give a "normal load" and higher "maximum load" tire pressure recommendation if there is only one correct maximum load pressure rating?
Is this just to provide greater comfort at the lower pressure at the expense of optimum tire performance?
Reply With Quote
  #5  
Old 08-31-2004, 07:31 PM
Registered User
 
Join Date: Aug 2003
Location: MA
Posts: 764
According to MB owner's manual, driving normally loaded car with the tire pressure for full load is OK. It whill make the ride somewhat harder.
__________________
1992 300D 2.5 turbo diesel. 319 k miles.
124.128 chassis, 602.962 engine, 722.418 tranny.
Reply With Quote
  #6  
Old 09-01-2004, 05:03 AM
neanderthal's Avatar
Registered User
 
Join Date: Feb 2004
Posts: 541
Quote:
Originally Posted by Dervman
While I don't dispute your answer, I'm curious as to why most vehicle manufacturers give a "normal load" and higher "maximum load" tire pressure recommendation if there is only one correct maximum load pressure rating?
Is this just to provide greater comfort at the lower pressure at the expense of optimum tire performance?
yes. the tire pressure stipulated is supposed to give the best ride. best is subjective of course. best ride does not always correlate to highest load capacity.

think of it this way: you have a one tonne pickup which you use to tow your polo horses/ race car/ luxury barge/ whatever. its rec air pressure is 80psi for teh rear wheels.

that air pressure recommendation is considering a load for the capacity of the vehicle. its designed to tow ***** and carry loads. yours is designed to be nice quiet smooth luxury car.

ergo to increase your lads you add pressure. while the truck is best served by reducing pressure if you want to increase comfort.

__________________
'O=00=O'
bmw 2002.
long live the legend
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 11:13 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page