MySwag.org The Off-road Camper Trailer Forum
General => General Discussion => Topic started by: Mungoman on April 30, 2012, 06:42:52 AM
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Yeah, like this one's never been asked before. But instead of hearing, "I run xxx and have never had any trouble," I'd like to hear the pitfalls of running too high apart from tyre wear.
Here's the deal. My manual says to run (180mpa) 26psi on all fours on the Prado 4WD. But every time I get the vehicle back from service they've put 32 or something in them.
So now the service guy tells me to run at 40psi to get better fuel economy. This really works but how safe is it?
Cheers
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I run 34psi when not towing and go for 38psi in the back and 36psi in the front with camper on. Most car companies recommend lower pressures for comfort and noise. Any tyre company will tell you that is to soft and lead to the outsides of the tyres wearing. :cheers:
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Yep, lots of opinions out there, but 26psi sounds a bit low? What tyres are you running? What does the sticker on the vehicle's pillar say, usually on the driver's side one?
Kevin
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Hey mate. 26 sounds way to low I would try the 4psi rule and see where that takes you. So start with the tires cold and put in x psi then go for a long enough drive to get the tires warm if they have increased by more than 4 psi they are to low and the tire is flexing to much and getting too hot and vise versa.
Shane
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The way I look at it is, the tyre's main job is to keep the rim off the ground. The more air, generally the higher off the ground the rim. BUT also, the more air, the less give in the tyre sidewall, and therefore more vibration from our not so smooth roads gets transferred to other parts of the vehicle, notably shockers, springs, and chassis and occupants.
If your requirement is to save a few bucks on fuel & bugger the suspension, then pump up.
Interestingly, a fellow over on LCOOL as a big-wig with Cooper Tyres in Australia. I seem to recal a post of his complementing another bloke & his tyre fitter for NOT slavishly going for 40 psi all round but adhering to Cooper's recommended pressure for the particular tyre, which was in the low to mid 30s I think.
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36-38psi on my BFG AT seems to work for me, any higher and it is a hard ride and it tends to lose front grip more often.
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Here are a variety of Links:
http://www.goodyearrvtires.com/tire-inflation-loading.aspx (http://www.goodyearrvtires.com/tire-inflation-loading.aspx)
http://www.hankooktyre.com.au/Serv/Inflation.aspx?pageNum=4&subNum=3&ChildNum=3 (http://www.hankooktyre.com.au/Serv/Inflation.aspx?pageNum=4&subNum=3&ChildNum=3)
http://www.tyrepower.com.au/tyre_pressures.aspx (http://www.tyrepower.com.au/tyre_pressures.aspx)
Most tyre manafacturers defer to the vehicle plackard pressures in the first instance as normal running pressures.
Personally, 26 psi seems a bit low, I usually run 28F/32R.
Its all a handling/comfort/load capacity/fuel economy trade off. Which/what do you prefer or want?
Pump them up to 36-40 psi to carry weight by all means, but the tyre will loose some handling capacity and the ride will be harder. And bear in mind, higher pressures mean a tyre is MORE susceptible to impact fractures from rocks and other objects.
:cheers:
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I have a 150 D4D with grand trek (OEM) rubber (soon to be changed).
On the black stuff I run 40psi or there abouts. Off the black stuff I run at 25psi.
If you run any less than around 40 on the road they will wear quickly.
The placard says 29psi all round.
Hope that helps
Regards
Crisp Image
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I have a 90 series and run Procomp ATs, 35-38 psi normally.
Wayne
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running D694's on my 90 series (265/70x16) and 34-36 sees them riding well and wear is very even across the width of the tread
should be ballpark for the 120 as well
Tyre pressures in the 20's - yes seems a bit low but good for the ride and I wonder if it's grandtreks you are running?
reason I ask is that high pressures in a tyre with light construction can increase carcass damage on sharp objects, maybe that's the thought behind it, but upping the pressures will do wonders for your fuel consumption
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Yeah, like this one's never been asked before. But instead of hearing, "I run xxx and have never had any trouble," I'd like to hear the pitfalls of running too high apart from tyre wear.
Here's the deal. My manual says to run (180mpa) 26psi on all fours on the Prado 4WD. But every time I get the vehicle back from service they've put 32 or something in them.
So now the service guy tells me to run at 40psi to get better fuel economy. This really works but how safe is it?
Cheers
What Brand? Are they the OEM Dunlops or another Brand? Does the tyre you running have a Light Truck construction?
What are you towing and whats the ball weight like?
:cheers:
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36-38psi on my BFG AT seems to work for me, any higher and it is a hard ride and it tends to lose front grip more often.
X 2
And as TOPNDR said go too hard & you place more stress on your suspension components & anything you may be carrying in the vehicle.
Cheers :cheers:
Frank
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BFG AT's @ 40psi works for me.
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I look at the tyre placard on the drivers door, then add 2 to 4 psi from what the manufacturer recommends.
Baz.
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On road - around 38, offroad - mid to high 20's depending on the severity of gravel/rocks etc
Cooper ATR'S on a 120 Prado.
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694LT's on a 90series TD 40psi all round. off road I play with the settings to see what happens normally 30 for dirt roads/tracks. 25-20 sand/ mud etc
really depends on load and towing. I have adj Tough dogs that also get adjusted as a secondary measure
i find that i have to get an alignment every 3-6 months just to keep things running straight
rgds
Gerry
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Hey mate. 26 sounds way to low I would try the 4psi rule and see where that takes you. So start with the tires cold and put in x psi then go for a long enough drive to get the tires warm if they have increased by more than 4 psi they are to low and the tire is flexing to much and getting too hot and vise versa.
Shane
This is the most accurate guage I have found on any offroad tyre. I am running Coopers on my Prado and on my Troopy. I have my own pressure guage and write down pressures as you test them, the four psi rule is the way to go. I used to run Michellin and have got over 100,000km on them but they wern't as good on the offroad area as the Coopers.
Kochy
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wow lots of tyre watchers on here ..... in the end I think if your wheels are aligned and balanced within spec and unless you run way over or way under pressure for extended periods, it really does not have a significant influence for normal use. Besides if you go off road you can rip a side wall on any aged tyre.
As to guides I read the max pressure off the side of the tyre and check them every 6 months or so, if I'm carrying a bit of weight I put some more air in.
This lack of OCD monitoring still gets between 50-100,000kms with BFG, MT's, Coopers, Dunlop and Goodyear.
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BFG AT's @ 40psi works for me.
same here
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Prado 150, cooper at3 tyres. 36 psi all round. Been running 36 up to 38 psi in prados for last 8 years.