tire pressure

stugots1982 · Post by **stugots1982** » Fri Apr 28, 2017 2:38 pm

just curious what everyone is running for tire pressure. wondering if more pressure has effected anyone milage much

Post by **Growlerbearnz** » Fri Apr 28, 2017 4:39 pm

My 31x10.5" tyres are at 26psi, though they're a bit bigger than stock size tyres. I've had them up to 35psi but didn't notice any difference in mileage, but the handling was a bit sharper- though they started wearing in the centre more than the edges.

Calculating the ideal tyre pressure is fairly easy: on the sidewall of the tyre it should say "maximum load XXX at XX psi". Measure your actual load (vehicle weight) as a percentage of the tyres maximum load, and divide the maximum pressure by the same percentage.

In my case the tyres say "maximum 1050kg at 50psi". Four tyres at 1050kg= 4200kg maximum, van's actual weight is 2200kg so 52% of the maximum. 52% of 50psi is 26psi.

stugots1982 · Post by **stugots1982** » Fri Apr 28, 2017 10:03 pm

is there anything you dont have an answer for?

stugots1982 · Post by **stugots1982** » Fri Apr 28, 2017 10:07 pm

ok so...in the case of the deli the vehicle weight may be X however the front wheels carry much more than the back so now i ask you. Do you have different pressures front and back and if so how did you come to the pressures which u decided.

Post by **Growlerbearnz** » Sat Apr 29, 2017 12:10 am

stugots1982 wrote:is there anything you dont have an answer for?

Do wrong answers count?

stugots1982 wrote:ok so...in the case of the deli the vehicle weight may be X however the front wheels carry much more than the back so now i ask you. Do you have different pressures front and back and if so how did you come to the pressures which u decided.

I don't, though technically it's the right way to do it. I figured if equal tyre pressures are ok with Mitsubishi, they're ok with me. That and if I went down that road my OCD would kick in and I'd be recalculating my tyre pressures every time I filled up with diesel (80 litres hanging out behind the rear axle) or towed the caravan (120kg towball weight) or filled the back of the van with firewood.

Post by **FalcoColumbarius** » Sun Apr 30, 2017 4:11 pm

I run Yokohama Geolandars (235/75R15) at 41PSI, typically. I also maintain this pressure when going into the toolies (FSR/OR). She maintains constant traction. I tried running them at 22PSI once ~ I didn't notice any noticeable difference, I could see the benefit in a sand dune but it didn't make much difference in my application other than the time it took to bring them back to street pressure with my compressor ~ okay in the sun, would hate to have to do it in the rain.

I've been driving with this pressure for nine years, which includes towing a trailer ~ 169,000+ kliks in all. Brakes like a charm, holds the road and is typically optimal regarding fuel economy. In this last winter, however, with all the excessive salt on the road, I think I'm going to need to redo the calliper cylinders, not to mention all my vinyl. Can't imagine what it's doing to the creeks.

Falco.

north54 · Post by **north54** » Sun Apr 30, 2017 4:57 pm

FalcoColumbarius wrote:I run Yokohama Geolandars (235/75R15) at 41PSI, typically. I also maintain this pressure when going into the toolies (FSR/OR). She maintains constant traction. I tried running them at 22PSI once ~ I didn't notice any noticeable difference, I could see the benefit in a sand dune but it didn't make much difference in my application other than the time it took to bring them back to street pressure with my compressor ~ okay in the sun, would hate to have to do it in the rain.

I've been driving with this pressure for nine years, which includes towing a trailer ~ 169,000+ kliks in all. Brakes like a charm, holds the road and is typically optimal regarding fuel economy. In this last winter, however, with all the excessive salt on the road, I think I'm going to need to redo the calliper cylinders, not to mention all my vinyl. Can't imagine what it's doing to the creeks.

Falco.

I second that! Same tires and pressure.

lrp374 · Post by **lrp374** » Mon May 01, 2017 11:06 am

I think Growler has the correct solution - maybe because it's similar to what I do. I have a set of Toyo AT2 tires with 40 000 km on them. I just rotated the tires again and each tire in 32nds is 9 8 9. This is the outside, center and inside measurement. I run 32psi front and 26 rear unless loaded. If the wear is linear I should get over 80 000 km with these tires! My center wear is a little higher using this philosophy, I would think @ over 40 psi the center would wear considerably faster.

Morgonzo · Post by **Morgonzo** » Mon May 01, 2017 12:47 pm

I just aired mine up (they looked low..) i'm running 30x9.5r15 BFG KO2's and have 42psi all around. They were just under 40 when I checked.

Cheers.

sealica · Post by **sealica** » Wed May 31, 2017 11:51 am

Hello,

Falco kind of touched on this ... I'm wondering if anyone has any thoughts on airing down for bumpy logging roads.

There is a lot of 4x4 overlander's who swear by this, with expensive compressors to match, etc.

It's probably my springs/tension bar, or perhaps just simply my shocks - but I'm seeking ways to make logging roads more comfortable. The van handles real well and traction is great, but there are times when bumps turn into loud bangs that don't sound to healthy - especially from the rear end ...

Anyone have experience airing down for rough roads? I've been doing this with my touring bike for the past few years (lowering tire pressure when hitting bumpy gravel tracks) and it certainly makes a huge difference in comfort. Less vibration overall. But it's a different animal - it's got tires, but no suspension.

Anyhow - thoughts on reducing tire pressure for rough sections? and are there well built compressors with in-line fuses that don't absolutely blow the bank. It's not practical if lowering tire pressure is going to require 30 minutes+ to fill them back up. Most of the compressors I'm reading about are intended for big rigs with 33" tires - I'm planning on keeping tires stock(ish) @ 235/75R15 ...

Lapprentis · Post by **Lapprentis** » Wed May 31, 2017 12:02 pm

sealica wrote: I'm wondering if anyone has any thoughts on airing down for bumpy logging roads.

There is a lot of 4x4 overlander's who swear by this, with expensive compressors to match, etc.

I would say it is the way to go: yes, the ride will be much more comfortable. It is also a good trick when stuck on sand

Now, most of us will not do it (unflate/inflate) because we are too lazy

My inflating setup is very simple: a cheap 12V tire pump + 12V electrical extension so that I can get to all the tire from the 12V jack, so simple

Total cost, at most 40CAN

Lapprentis

sealica · Post by **sealica** » Wed May 31, 2017 2:34 pm

Lapprentis wrote: I would say it is the way to go: yes, the ride will be much more comfortable. It is also a good trick when stuck on sand Now, most of us will not do it (unflate/inflate) because we are too lazy My inflating setup is very simple: a cheap 12V tire pump + 12V electrical extension so that I can get to all the tire from the 12V jack, so simple Total cost, at most 40CAN
Lapprentis

So I'm wondering roughly how long to get all four tires back to street pressure once you've aired down, which from as I understand it is usually in the less 10-30% range depending on surface. Most of the info I'm coming across is time for airing a tire from flat =)

Post by **FalcoColumbarius** » Sun Jun 04, 2017 7:39 pm

Lapprentis wrote:
sealica wrote: I'm wondering if anyone has any thoughts on airing down for bumpy logging roads.

There is a lot of 4x4 overlander's who swear by this, with expensive compressors to match, etc.
I would say it is the way to go: yes, the ride will be much more comfortable. It is also a good trick when stuck on sand Now, most of us will not do it (unflate/inflate) because we are too lazy My inflating setup is very simple: a cheap 12V tire pump + 12V electrical extension so that I can get to all the tire from the 12V jack, so simple Total cost, at most 40CAN

Lapprentis

Forty-one PSI. I soften my shocks (Rancho 9000's). Forty-one is optimal for traction yet good fuel economy. I wouldn't want to run out of fuel in the toolies.

Falco.