# Tire Tech - Load Carrying Capacity vs Air Pressure, R32



## Eric @ TIRE RACK (Jan 27, 2000)

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*LOAD CARRYING CAPACITY*
Only when the vehicle manufacturer requires the maximum psi for load carrying capacity
does the load rating become a critical/safety issue. I haven't checked the W8 nor the
'big body' Audi cars that are _potential_ "suspect vehicles." I've only seen one vehicle
(The Touareg), where it is necessary to match the tire's load rating when selecting
tires.
_Always keep in mind, to take a look at your owner's manual for further vehicle specific
information._ But for the most part most standard passenger vehicles, Passat (non W8),
Golfs & Jettas, etc. are not normally a load carrying capacity concern.
Maximum load carrying capacity of a standard load P-metric tire is achieved at 36 psi.
Additional psi (air added to the tire), is for the express purpose of providing better handling/stability (typically at the high speeds, which are common in the Motherland
on the Autobahn). Adding air to SL tire(s), above 36 psi does not provide any additional/increased load carrying capacity.
*** Never exceed the maximum inflation pressure that is on the side of all tires.
An Extra Load tire provides a couple of hundred lbs of load carrying capacity. As stated,
the need for an Extra Load tire is a rare occurrence (There are certain, rare applications),
where such tires are warranted. In my experience, there is no discernable difference in
ride quality between a standard load vs. an extra load tire.
Maximum Load of a Standard Load (SL), Tire is achieved @ 35psi. 
Maximum Load of a Extra Load (XL)/Reinforced Tire is achieved @ 41psi.

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..................................................*GAWR* *.:R32*.........Front 2315......Rear 2205 

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OEM R32 Tire
225/40-*18* GY EAG F1 GS-D3 92Y
EXTRA LOAD (XL) 92 
92 Load Index .............. 1389 lbs.
Max. Inflation Pressure... 50 psi.
[for Mounting (Beading) purposes only].

Max. Load achieved @ 41psi.
Adding more psi does not
increase load carrying cap. 
_____________________________

225/40-18 SL 
Load Index....... 88 
Maximum Load.............. 1235 lbs.
Max. Inflation Pressure... 51 psi.
Max. Load achieved @ 35psi
Adding more psi does not
increase load carrying cap.
_____________________________

225/45-*17* XL
Load Index....... 94 
Maximum Load.............. 1477 lbs.
Max. Inflation Pressure... 50 psi.
_____________________________

225/45-17 SL
Load Index....... 91H 
Maximum Load.............. 1356 lbs.
Max. Inflation Pressure... 44 psi.
_____________________________

*205*/50-*17* XL
Load Index....... 93
Maximum Load.............. 1433 lbs.
Max. Inflation Pressure... 50 psi.
_____________________________

205/50-17 SL
Load Index....... 89 
Maximum Load.............. 1279 lbs.
Max. Inflation Pressure... 51 psi.
_____________________________

Of all the above listed tires, the lowest load index/load carrying capacity
tire is the 225/40-18 SL Load Index....... 88 Max Load........ 1235 lbs.
@ 32 psi this SL tire still has 1166 lbs. load carrying capacity.
1166 X 2 = 2332 lbs total load carrying for the (front), axle.
GAWR frt = 2315 lbs.

Matching Tires on All-Wheel Drive
Tire Rotation
Air Pressure
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As Moderator of The Wheel & Tire Forum, I ask
that if you require my technical input, please
include my name, *Eric* as the 1st word in your
post/question Topic Title.
If at all possible, Please refrain from Emailing Me.


_Modified by Eric @ TIRE RACK at 7:48 PM 3-16-2005_


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