VW T4 Forum - VW T5 Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Hi

On my 2014 VW T5.1 Transporter I have 20" wheels fitted with HAIDA Racing HD921 275/40ZR20 106W XL tyres, please can you tell at what pressure I should I run them.

Kind regards
Rob
 

·
Premium Member
Joined
·
893 Posts
Hi,
Running 275 40 20 106XL tyres for last 4years 42psi all round as recommended by Vanstyle where I bought my wheels. T:
No issues at all.
 

·
Registered
Joined
·
58 Posts
Your 106XL means that the tyre is allowed to carry 950kg AT 290kPa/2.9bar/42 psi upto 160kmph/99mph.
Depending on speedcode the tyremakers organisation says upto 190kmph/118mph for W speedrated, and 220kmph/137mph for Y
But for laws of nature wich always rule above rules of organisations, keep it to 160kmph/99mph, so speedcode you forgot to give is not that important to determine the needed pressure.

I once got hold of the official formula to calculate pressure for load on tyre, and system for highening up the 42 psi in this case, for higher speed and went running with it.

So if you can produce axleweights in use, and give maximum speed you use( and wont go over for even a minute) I can calculate a lowest safe pressure, and a pressure with maximum reserve with still acceptable comfort and gripp. Then I will show how I calculate it for " nice to know" purpose.

To law , your given tyres are allowed for a Maximum Permissable Axleweight of 1900kg. I daubt if your MPAW comes to that.
So if your max used speed is below 99mph, you can do with lower pressure then 42 psi.

The pressure prescription on car is mostly calculated for MPAW's and max technical carspeed.
 
1 - 6 of 6 Posts
Top