D4 tyre pressure?

[kogarah]

This afternoon notice left rear tyre looked a little bit flat than others. checked and found a screw in it. Spent 20 mins in the Tyre shop and the tyre was fixed. I asked boys pump up the fixed tyre to 40PSI.

Late in the service station I found the other 3 tyres are all set at 48PSI.......Great.

As this is first time I check the tyre pressure after I picked up this car, I was thinking the tyre should between 36-42PSI for normal road driving. This is the recommend pressure.

Any idea about what is the correct pressure?

[Celtoid]

Hey mate,

If you are running the standard 19" Wranglers the plackard is on the drivers door.

Standard load, 33 and 36PSI...front and rear.

Cheers,

Kev.

[oldsalt]

Late in the service station I found the other 3 tyres are all set at 48PSI.......Great.





Never trust a service station tyre pressure guage ... buy yourself a "good" guage and keep it in your glovebox ... then get an on-board compressor fitted and save yourself the drive to the service station as well :D

[AGRO]

Strange you should mention this set of circimstances.

In November 2010 I took delivery of my new D4. On the way home and at an odometer reading of only 200km I had a puncture on an open highway. There was a small piece of wood centre tread. My off road only involved a layby for a cuppa - I swear it!!!

I took the tyre in and had it plugged and tested. I had the tyre pressure set at 38 for the rear.

When home used my "glove box" gauge to check the others and found them all to be set at 50psi. Interesting - I thought I was seeing things and couldn't believe it. Helps with the fuel economy but makes the tyres more suceptible to puncture.

I ran this past my dealer/servicing but received absolutely no response - ever about the issue.

Can anybody in/or familiar with the industry indicate whether or not vehicles in transit from the factory have tyres set at high pressure and whether or not tyre pressure is part of a predelivery check.

I presume pressures are set high whilst the vehicle is at "transit height" and on the boat from "old Blighty".

Anyway I'm dumb igorant and can't read a tyre gauge - apparently. Its very hard to prove tyre pressures after the event and in any case they aren't covered when punctured.

[discojools]

There seems to be a thing here in Aus about running higher than recommended tyre pressures. I never came across this while living in the UK and Europe. I have had one incident which could have been really serious after picking my car up from service where they pumped the tyres up to 45psi.. had to do an emergency stop after a car in front had decided to stop at a green light. had absolutely no grip and skidded for over 20 meters. Also have a friend who had a similar experience after picking his Hilux up from service. All of the tyrefitters I have used here always say that it's best to run higher tyre pressures cause it's better for economy. Rubbish! Give me grip over economy any time. I run Landrover's recommended pressures all the time unless I am fully loaded in which case I pump up the rears to the recommended pressure by LR. This gives the best ride and max amount of grip.
I firmly believe that one of the reasons that so many people can't stay on the road here is because they run higher pressures in their tyres.

[Disco4SE]

Agree with you Jools re: tyre pressures. I would rather lose a slight bit of fuel economy and know that my vehicle will stop and behave how I want it to.
Agree with Oldsalt re:tyre pressure gauges. Go and get yourself a good tyre pressure gauge and keep it in the glovebox. I have a gauge connected to my compressor in the garage. It is about 4psi out with the one in my glovebox, which is 4psi out with the local service station (the other way), which is also out with my local tyre dealer.
Cheers, Craig

[Discophil]

Couldn't agree with you more Jools. Not only do I want my car to stop effectively, the car rides so much better on our "beautifully cobstructed" Australian roads...

[sniegy]

Hi all,
Tyre pressure from the UK are set at 60psi, to avoid flat spotting tyres.
Especially Soft compound tyres, Continental, Pirelli etc

Tyre pressures are set at (with us) at 33/36 psi normally +/- 2psi.
Also dont forget when driving the pressure will increase with heat, so you may set them at 40psi (as i do with mine) but 20mins driving you will see an increase up to & possibly beyond 50psi.

Cheers:p

[Ashes]

I've found when using the tyredog sensors you can generally rely on around a 10% increase in tyre pressure from cold to hot. ie 36psi cold on a normal day will increase to around 40psi on the highway.

[discojools]

Thanks Sniegy for info about tyre pressures for cars in transit from UK. But why have all the tyre dealers I have dealt with here insist that it is best to run tyres at well above manufacturers recommendations? I still think it is wrong and dangerous..

Discojools.

[Ashes]

My observations from riding a motorbike where variations in tyre pressure are far more noticable are and for standard road tyre (race tyres are different)..
- higher pressures certainly give you better fuel economy
- the higher the pressure the harsher the feedback from the road which means less feel and control.
- high pressures definately increase stopping distance and more so in slippery conditions (dirt, water) as the contact patch is smaller. Bikes rely on increasing the contact patch size on the front tyre to be able to stop. For offroad on the bike I'm airing down to 22-25psi like I would in the 4wd.

I run my bike tyre at recommended pressures, around 32psi as it feels better. Being able to stop and maintain traction are more important to me than fuel economy and longer tyre life.

[TerryO]

Thanks Sniegy for info about tyre pressures for cars in transit from UK. But why have all the tyre dealers I have dealt with here insist that it is best to run tyres at well above manufacturers recommendations? I still think it is wrong and dangerous..

Discojools.


For what it is worth I agree with your comments Discojools, running tyres at the recommended tyre pressures has to date always worked well for me. I to have noticed when I get new tyres the fitters nearly always put in higher then recommended pressures. I have tried on many occassions to find a better tyre pressure for my driving but usually end up back at the recommended pressure after dicking around.

As for bike tyres especially with road racing that is a whole different science compared to road tyre pressures, as there are so many factors that need to be taken into consideration before the correct tyre pressure is found. With bike racing more often then not most of the damage is caused by cold tearing which can be caused by not only tyre pressure but also suspension settings.


cheers,
Terry