<span class="highlight">Tyre</span> <span class="highlight">Pressures</span> when towing?

Adam J,

Not a lot of information to give an educated reply, but a couple of things to start the WDH should not influence the tyre pressure.

You can start with what you think is best and try the 4 PSI rule. After driving for say 1 hour you check the pressure against your start pressure, and if it has gone up by say 4 PSI you are about correct, if it is less than 4PSI you may have started a bit high, if it is more then you started too low.
Depending on whether you have 2 axles or 1 or if the tyres are 4WD or normal LT car type tyres will further influence the end result.

In other words more info is required.

My Prado/Coromal Pioneer XC has from front to back 34, 36, 36 and 36 using Bridgestone 265x75x16 LT 694/693 tyres.

Regards,
Jim

Hi I run 245 70 16 Tyres and run 35 cold around town no load, 38 psi towing and down to 30 psi offroad on hard gravel. Just done the oodnadatta track last week and the leaflet for the track recommends no higher than 25 psi to aviod puctures, seems a bit low for such a long haul but they should know as they fix all the blowouts from over inflation.
Try the 4 psi rule and see how you go.

The inflation pressure for course gravel roads- to avoid punctures is 80% of the correct on-road pressure. The correct on road pressure is easily calculated from the info on the side of the tyre.

eg.
If your tyre has the following info (just as an example)

max pressure 60 psi
max load per single 1000 kg

then for a 2000 kg van with two tyres this means 60 psi inflation on road.

But for a 1000 kg van it would be 30psi plus 4 psi (safety factor) = 34 psi

So for gravel 0.8 x 34 = 27 psi


Or use the footprint method 220 to 240 mm long footprint on course gravel.

Don't forget 80% of the pressure = no more than 80% of the speed, so don't go above 80-85 kph at these gravel pressures.

A good towing course will assist in this an lots more.

Thanks guys, all good tips / info. We have a 2010 Mitsubishi Challenger, running BFG A/Ts 275/65 17's. The van is a single axle Paramount Duet 18". Thanks for the feed back. I really appreciate it. I had a rough idea, but its good to here from people with more experience. I thought I would have had to bump it up a little more than 4PSI. So its a good thing I asked the question I'm guessing Thanks and have a great weekend.