wintersun wrote:
I have never seen where a truck manufacturer recommends a lower tire pressure based on no load. In my own experience the tire manufacturers' charts result in underinflated tires with uneven tread wear and shorter life.
Underinflated tires will also negatively impact road handling and stopping distance and the greater amount of sidewall flexing will make them run hotter - this was why the Ford Explorer's were experiencing blow-outs and killing people.
Anyone who has gone up a load range with the tires on their truck has experienced better handling from the stiffer tires. The offset is a harsher ride.
A 200# fiberglass cap will do a lot to smooth out the ride on a heavy truck when there is no weight on the hitch. You could achieve the same by putting a couple bags of sand in the bed.
When I have looked at trucks on dealers' lots I have noticed wide variations in the payload ratings of the trucks based on the tires that were provided at the factory. I have seen factory supplied truck tires with load capacity ratings from 2200 up to 3200 lbs. on heavy duty models.
I was thinking the exact same way until I started having a second hard look at the Ram 2500 Longhorn. Here is what the door jamb decal reads. This is for a new 2013 crew cab, diesel, 4x4:
Max load: Front = 60 lbs and Rear = 70 lbs
Light load: Front = 50 lbs and Rear = 40 lbs.
On top of this, Ram has the ability to adjust the tire pressure monitor for both Max and Light load readings.
All that said there are a couple posts that make complete sense now that I go back and read about them supporting the Max / Light tire pressures and the benefits of following the manufacturers recommendations. In fact, if you go to the Ram site, you can download the manual,and the complete detail regarding the suggested 2 sets of tire pressures can be found in 490 to 521.
I know - at first I thought there must be some mistake or I misunderstood what was going on with the Ram 2500's as I never heard of doing this before. Then again, I'm an "amateur" when it comes to tow vehicles of this size!