heavy loads and tyre pressure

Got some advice to share or a question to ask? Heres the place to do it!
griffo1963
Here and there
Posts: 31
Joined: July 16th, 2012, 6:51 pm

heavy loads and tyre pressure

Unread post by griffo1963 » December 8th, 2014, 6:49 pm

hi i would like to know your thoughts on Tyre pressure and heavy loads we do a lot of beach camping and have just upgraded to a slide on camper now im not sure exactly of the wet load weight as yet but have been told its around one ton in the old scale.now need to know is this we have sold the hilux and bought a 2000 gu 42lt turbo diesel ute witch i though would better suit our needs better and it does no problems its has 9 leaf springs and i have just put air bags on the ass to help with the extra weight .on the first trip i worked out my air bags were to high 50psi so i let them down to around 35 psi and they complement the back springs great soon to come new shocks and that should be all i need.ok here is my question we have done a lot of beach but never in this car and never with the new weight factored in i would let my hilux down to around 18 psi fully loaded and 98% of the time that would keep us out of trouble but with the extra weight now and in a different car with a different set up should i go around 23 psi on the ass and 20 or 18 psi in the front and also can you safely use different pressure in the rear and the front? im thinking it wouldn't hurt the car on sand all thoughts welcome need to know cheers griffo
You do not have the required permissions to view the files attached to this post.
get out when you can
www.showcaseyourmusic.com/stillworkin
allaboutpoolsafety@hotmail.com
pool safety inspector brisbane

Dmaxqld
Been here a while
Posts: 364
Joined: November 28th, 2013, 12:01 pm

Re: heavy loads and tie pressure

Unread post by Dmaxqld » December 8th, 2014, 7:24 pm

I would measure your tyre's footprint without the slide on camper on the back at your normal sand driving pressure. I would then put the camper on and adjust your tyre pressure to achive the same foorprint. Simple way to measure the footprint is with two bits of wood, one in front and one behind the tyre then measure the distance between.

griffo1963
Here and there
Posts: 31
Joined: July 16th, 2012, 6:51 pm

Re: heavy loads and tie pressure

Unread post by griffo1963 » December 8th, 2014, 7:30 pm

that makes sense mate good advice ill try it this week end with no weight on up at bribe if i get the chance
get out when you can
www.showcaseyourmusic.com/stillworkin
allaboutpoolsafety@hotmail.com
pool safety inspector brisbane

Dmaxqld
Been here a while
Posts: 364
Joined: November 28th, 2013, 12:01 pm

Re: heavy loads and tie pressure

Unread post by Dmaxqld » December 8th, 2014, 7:50 pm

Do the footprint measurement on your garage floor. More accurate and easier.

Peter Aawen
Admin
Posts: 20807
Joined: June 17th, 2005, 8:01 pm

Re: heavy loads and tyre pressure

Unread post by Peter Aawen » December 8th, 2014, 8:30 pm

Check out the thread(s) on the 4psi Rule - it's a 'rule of thumb' used across the motoring world to determine the most appropriate pressure for your vehicle with the load that's on it at the moment driving on the surface you are on at the time....

viewtopic.php?f=175&t=77750
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

Aaron Schubert
Need to get out more
Posts: 4682
Joined: November 9th, 2009, 7:32 pm

Re: heavy loads and tyre pressure

Unread post by Aaron Schubert » December 8th, 2014, 9:12 pm

I would be seriously concerned about the weight you are carrying, especially given the fact that you are running air bags. Air bags and leaf springs are not an ideal combination.

My suggestion would be to see an engineer, and discuss the sort of 4WDing you plan on doing. Long term, I wouldn't be surprised if the chassis bent.

In regards to the tyre pressures, I'd still say you could go down to around 18 PSI in the sand. Just pay attention to how the tyre bulges, and don't corner too quickly

Aaron

Aaron
Looking for somewhere to go 4WDing in WA? Check out WA 4WD Tracks

My 80 Series Landcruiser

griffo1963
Here and there
Posts: 31
Joined: July 16th, 2012, 6:51 pm

Re: heavy loads and tyre pressure

Unread post by griffo1963 » December 10th, 2014, 7:02 pm

hi aaron thanks for you comments so far i have not bent anything due to the fact i done some research and head the same thing about springs and air bags and what i have so far is if you pump up to around 35 psi on Firestone air bags you take some weight off your springs the trick is not to put all the weight on your air bags let them complement the springs and work together .on my first trip with the air bags fitted i pumped up to 50 psi max it felt real bad i was not game to turn even on slight bends on road it felt un easy so i pulled over and went down to around 35psi and straight away it felt a lot more stable so i think the big problem surrounding air bags and springs is over inflation ex expecting the air bags to hold all the weight .let me know your thoughts cheers griffo
get out when you can
www.showcaseyourmusic.com/stillworkin
allaboutpoolsafety@hotmail.com
pool safety inspector brisbane

Aaron Schubert
Need to get out more
Posts: 4682
Joined: November 9th, 2009, 7:32 pm

Re: heavy loads and tyre pressure

Unread post by Aaron Schubert » December 10th, 2014, 8:08 pm

I'm glad to hear you are looking at it logically. If your air bags took all the weight you would be at serious risk. Still, why not install springs that would take all the weight, across the engineered points from Nissan? I'd be getting the vehicle weighed, and still speaking to an engineer.

Aaron
Looking for somewhere to go 4WDing in WA? Check out WA 4WD Tracks

My 80 Series Landcruiser

FJRider
Been here a while
Posts: 313
Joined: February 16th, 2012, 12:47 pm

Re: heavy loads and tyre pressure

Unread post by FJRider » December 10th, 2014, 10:34 pm

What Aaron says get the right springs for the job , that camper is going to be heavy . I bet you are well over GVM .

Return to “Driving Tips and Techniques”