Outer Limits 4x4 Board

G Day,

Do you guys know if there is a chart where you can verify the proper tire inflation, I'm asking this because a I have a 32X11.5R15 Maxxis Bighorn tires and I was told that the correct way to calculate the proper tire inflation is take the maximum load cap in my case is 50 PSI and rest 10 PSI, so in my case the proper tire inflation will 40 PSI for daily use, it's that correct????

And something else that I would like to know is if I'm going to do some off road and I need to under inflate my tires, what's the best way to calculate that.

Cheers....

macorti wrote:G Day,

Do you guys know if there is a chart where you can verify the proper tire inflation, I'm asking this because a I have a 32X11.5R15 Maxxis Bighorn tires and I was told that the correct way to calculate the proper tire inflation is take the maximum load cap in my case is 50 PSI and rest 10 PSI, so in my case the proper tire inflation will 40 PSI for daily use, it's that correct????

never heard of the 'formula', but it does depend on your load. personally I like to sit at around 36psi.

macorti wrote:And something else that I would like to know is if I'm going to do some off road and I need to under inflate my tires, what's the best way to calculate that.

Cheers....

It depends on terrain, the tyre itself, the load your carrying, etc. start at about 24psi and adjust from there. without bealocks, you wouldnt want to go lower than about 14psi. But again this depends on your loads your carrying, adn how the tyre bags out.

Remember to keep the speed down if the tyres are down.

HeathGQ are you using the same tire size as me (32) or you are using 33, and if you are using 33, can the 36 PSI can apply as well for my 32's?

Personally i wouldnt trust a formula. Of all the different tyre sizes i have owned, at the same pressure none would have the same profile. Over-inflation will wear the centre of the tread, under-inflation will wear the outers. Both conditions will cause less than optimal grip. You can keep adjusting the pressure till the cold and hot pressure of the tyres has the least variance, not sure if this method is any good, but some people use it.
Remember that as the tyres get driven on, they heat up and the air expands, increasing tyre pressure. So checking tyres cold, then driving round a bit, will increase the pressure reading.


Layto....

Cooper Tires have a brochure that has a pretty good formula for different tyre pressures for size, weight of vehicle, driving conditions. Should be able to get one from where they sell them

Thank you very much mates, I will run a test in order to see the correct "cold" pressure and the "hot" as well.

OK here tis.........go for a drive up the h'way for a bit.....If a tyre increases in pressure (from cold) more
than 3-4 psi it could be considered to low to start with. If it doesn't
increase in pressure or increases only 1 psi then it was too high
to start with.
Even using an accurate guage it's still
difficult to find the premium pressure for a given tyre, load,
ambient temp...etc. etc. etc.
Rule of thumb is that your tyres should gain pressure on an extended
trip, but it should only be 2-3-4 psi.....

Pot stirred....Dave

Thanks a lot mate, I'll chek that.....

i have 33 inch bighorns and the best wearing preasure is 32 ish psi
any higher and the center starts to wear out faster

but you have 32 inch tyres and i think they are totally different as the max pressure on mine says 36 psi