Tire inflation
Got E rated tires installed, 80psi max, Tire guy said it would be better to run around 65-70 psi as tires heat up. Always thought I should run max cold rating 80psi. FW weight is around 9000 lbs hooke...
Forum Discussion
As usual, lots of opinions.
1) On every vehicle sold in the US, there is a vehicle tire placard which lists the original tire size and the specified pressure for that size. On motorized vehicles, the placard is usually found on the driver's doorframe, but it can also be found on other doors , other doorframes, the glovebox, fuel filler door or on the trunk lid. For trailers, it can be found on the left front corner, on the tongue, on a door, in a cabinet.
Find the vehicle tire placard and make a note of the tires size (including the letters) and the specified pressure.
2) Car manufacturers have generally done a decent job of sizing their tires relative to load carrying capacity. SUV and Light Truck manufacturers, not so much - although since 2008, they are on par with the car manufacturers. Trailer manufacturers are the worst of the bunch and many trailers have come with inadequate tires (from a load rating perspective).
3) If you are NOT using the tire size (including the letters) as listed on the vehicle tire placard, then you'll need to recalculate. The calculation isn't difficult, but does require the use of the tire load tables.
4) The owners manual should give you guidance about what inflation pressure to use, including what to use if the vehicle is not fully loaded (like an empty pickup truck). If the owners manual doesn't say anything about less than fully loaded, then the vehicle manufacturer probably intends for you to use the placard presure even when empty. (They do test the vehicle that way!)
5) Tire load tables are primarily for vehicle manufacturers to use. If the vehicle manufacturer has done a good job, the vehicle tire placard and owners manuals ought to be enough information.
6) Tire wear more affected by other things than inflation pressure. For example, steer tires tend to wear on the shoulders and drive tires tend to wear in the center. Inflation pressure has to be changed a lot to get the same affect. In other words, inflation pressure shouldn't be the first thing that comes to mind when you see uneven tire wear.
7) As a general rule, cars do NOT use the maximum inflation pressure of a tire. As a general rule, SUV's and light trucks do NOT use the maximum inflation pressure. As a general rule, trailers DO use the maximum inflation pressure.
1) On every vehicle sold in the US, there is a vehicle tire placard which lists the original tire size and the specified pressure for that size. On motorized vehicles, the placard is usually found on the driver's doorframe, but it can also be found on other doors , other doorframes, the glovebox, fuel filler door or on the trunk lid. For trailers, it can be found on the left front corner, on the tongue, on a door, in a cabinet.
Find the vehicle tire placard and make a note of the tires size (including the letters) and the specified pressure.
2) Car manufacturers have generally done a decent job of sizing their tires relative to load carrying capacity. SUV and Light Truck manufacturers, not so much - although since 2008, they are on par with the car manufacturers. Trailer manufacturers are the worst of the bunch and many trailers have come with inadequate tires (from a load rating perspective).
3) If you are NOT using the tire size (including the letters) as listed on the vehicle tire placard, then you'll need to recalculate. The calculation isn't difficult, but does require the use of the tire load tables.
4) The owners manual should give you guidance about what inflation pressure to use, including what to use if the vehicle is not fully loaded (like an empty pickup truck). If the owners manual doesn't say anything about less than fully loaded, then the vehicle manufacturer probably intends for you to use the placard presure even when empty. (They do test the vehicle that way!)
5) Tire load tables are primarily for vehicle manufacturers to use. If the vehicle manufacturer has done a good job, the vehicle tire placard and owners manuals ought to be enough information.
6) Tire wear more affected by other things than inflation pressure. For example, steer tires tend to wear on the shoulders and drive tires tend to wear in the center. Inflation pressure has to be changed a lot to get the same affect. In other words, inflation pressure shouldn't be the first thing that comes to mind when you see uneven tire wear.
7) As a general rule, cars do NOT use the maximum inflation pressure of a tire. As a general rule, SUV's and light trucks do NOT use the maximum inflation pressure. As a general rule, trailers DO use the maximum inflation pressure.
