SL55/63/65/R230 AMG: Tire Pressure Question
Thread Starter
Junior Member
Joined: Jan 2021
Posts: 16
Likes: 2
From: Southern California
2017 SL63
Tire Pressure Question
2017 AMG SL63 with Michelin Pilot Super Sport. 19 inch front and 20 inch rear
255/35/ZR19 (96Y)
285/30 ZR20 (99Y)
Drivers Door says 48 PSI Front and 46 Rear
Gas Cap says 35 Front and 33 Rear for speeds up to 155 mph unloaded
MB Service Center on the phone says follow the gas tank. Why is there a 13 pound differential between the recommendation on the door and the gas cap? Do I follow the gas cap?
THANKS! The tire sidewall says max pressure is 50 PSI. MB says the original equip was Continental tires. Live in warm weather Southern Calif. (where it never rains but it pours).
255/35/ZR19 (96Y)
285/30 ZR20 (99Y)
Drivers Door says 48 PSI Front and 46 Rear
Gas Cap says 35 Front and 33 Rear for speeds up to 155 mph unloaded
MB Service Center on the phone says follow the gas tank. Why is there a 13 pound differential between the recommendation on the door and the gas cap? Do I follow the gas cap?
THANKS! The tire sidewall says max pressure is 50 PSI. MB says the original equip was Continental tires. Live in warm weather Southern Calif. (where it never rains but it pours).
Member
Joined: Oct 2009
Posts: 78
Likes: 15
Seat Alhambra
Your tires are XL wich are allowed to carry maxload AT 42 psi upto 160kmph/99mph.
End 2007 , I got hold of the official formula and system to calculate presdure for a load on tire and speed used, and went running with it.
since 2006 also used in America.
Now dont use that anymore, but my determined saver and simpler system.
Will give an on the road calculation that comes verry close to laws if nature ideal.
1. Determine load on tire ( the most tricky part)
2. Determine maxload of tire from the loadindex.
3. Substract from 1 and 2 100lbs/ 45kg.
4 devide outcome 3 , and multiply with referencepressure of 42 psi for your XL.
Most ZR tires with lower hight/widt division are XL.
For speed counts, every 10kmph/6.5 mph different then 99mph , 1 loadindexstep different.
higher speed / lower loadindex.
Lowrr speed / higher loadindex.
In case axleweights, add 10% to it for reserve.
To be continued, with examples
End 2007 , I got hold of the official formula and system to calculate presdure for a load on tire and speed used, and went running with it.
since 2006 also used in America.
Now dont use that anymore, but my determined saver and simpler system.
Will give an on the road calculation that comes verry close to laws if nature ideal.
1. Determine load on tire ( the most tricky part)
2. Determine maxload of tire from the loadindex.
3. Substract from 1 and 2 100lbs/ 45kg.
4 devide outcome 3 , and multiply with referencepressure of 42 psi for your XL.
Most ZR tires with lower hight/widt division are XL.
For speed counts, every 10kmph/6.5 mph different then 99mph , 1 loadindexstep different.
higher speed / lower loadindex.
Lowrr speed / higher loadindex.
In case axleweights, add 10% to it for reserve.
To be continued, with examples
