First truck; looking for tire inflation advice for hauling weight

Haha. Yeah, yours looked familiar as well. Thanks again for your advice. Much appreciated. I gotta learn somewhere!

 

No problem! That's what these places are for! I learn new things every day, as well.

 

Another quick chart that shows relationship of air pressure to weight rating.
LT-Metric Tire Load and Inflation Table - TirePressure.com

 

With full rated load 36 front & 40 rear with tires cold works well. Some times I need to haul a few hundred pounds more, I'll add another 4 or psi.
I run normally 30psi cold without much load, but I'm running back roads and don't see over 60mph. I mainly want to keep comfortable over bumps, rocks and potholes.
For highway running, that's on the low side. A fewmore pounds will extend tire life, improve high speed handling, and increase fuel economy.
After warming up tire pressure will increase up to 10% from cold.

 

Since this is your first truck here are a few things to get you going.

1) You did the smart thing by looking at the door jamb sticker and you are correct -- a full passenger load can use up most of the payload. You can have people or cargo, just not at the same time.

Terms:
Gross Vehicle Weight (GVW) -- total (legal) weight of truck including cargo, passengers, fuel, trailer tongue weight -- this is what they check at a weigh station, overweight = fines $$ -- Note: Most personal trucks don't get weighed unless the operator is doing something dumb.

Curb weight -- Truck when empty, no passengers or cargo

Payload -- GVW - Curb = Payload -- this is the amount of weight available to do work

Compare the Tacoma to the Tundra below: (average numbers)
Tacoma: GVW 5600 - Curb 4400 = Payload 1200
Tundra : GVW 7200 - Curb 5500 = Payload 1700

The Tundra can carry 500 lbs more but also carries 1100 lbs more truck to do it.

These are light duty consumer oriented trucks not an F-350, they are intended to be "handy duty" not heavy duty. Consider also that 1200 lbs is not an insignificant amount of weight -- imagine carrying your cement bags up a flight of stairs for example.

2) Tires: Tire weight capacity and maximum pressures are on the sidewall. Higher pressures allow the tire to carry more weight, lower pressures give better ride, handling and wear when not fully loaded. You can (and should) inflate the tire to a higher pressure up to the maximum listed (on the tire) when heavily loaded.

As you observed, the tires looked squishy under the heavy load, this is bad. Squishy tires flex a great deal when driving creating heat which in a tires #1 enemy, heat causes blowouts. Squishy tires also sway and wobble causing the loaded truck to handle poorly, squishy tires wear out prematurely.

3) Loading: Always try to put the majority of the weight toward the front of the bed when possible, this puts the weight between the 2 axles rather that concentrating it on the rear which makes the steering too light. Attention to how the weight is loaded makes the truck handle much better and safer.

Summary:
1) You did the smartest thing already -- ask questions and learn, use your head and be safe.
2) Air up when loaded up, use the door tag pressures when empty - you may adjust these up slightly to suit your daily needs.
3) Be conscientious when loading, makes the drive better and safer -- remember a loaded truck drives and handles different than an empty truck, also trucks handle different than passenger cars, be alert.
4) Respect the truck for what it is, a handy work horse - not an F-350 -- just because you can put it in the bed doesn't mean you should.
5) Enjoy the new truck!

 

Thanks so much for this! It’s a great overall explanation!

 

Glad to help, I had to learn everything the hard way -- you don't need to.

 

A subtle point many people do not understand is the meaning of a "Cold" tire.

This is very simple. The meaning is the tire has NOT BEEN DRIVEN that is at atmospheric temperature.

FWIW, you can look at the tire sidewall for the maximum weight and pressure. You can use simple ratios to estimate the tire pressure when loaded.
Or you could just inflate to max pressure, load and go. Then reduce pressure when unloaded.

 

Your Duratrac has the same load rating as the stock tire; 30 psi is perfectly suitable.

That said, load capacity of your tire will continue to increase until 36 psi, at which point anything over 36 psi is used to maintain the speed rating.