tyre dog adjustment

Agree with Graham entirely: it's really not the pressure, but the (sudden) change in pressure in any one tyre that is important. Also, I agree with Graham that, heavily laden or towing, hot pressures are often 6 or even 7 psi up on cold, and the tyres facing the sun will be at least a couple of pounds up on those in the shade!!
Still good value, methinks

yeh i realise that it is more for pressure drop but to have it more accurate would be nice .

Well if you accept that THEY are correct and the others arent you wont need to worry.

If you use a servo gauge you could get 10lb difference in them the way they get chucked around doesnt do anything to make them perfect.

The tyre dogs if Im correct rely on the tyre pressure pushing on a membrane and are sealed from the outside air whereas a normal gauge is just air pushing up a tube and hopefully the seals in the tube are up to it to give the pressure.

I have found my similar type to be consistent with the Bushranger tyre gauge I have so accept the readings they give.


Its the 10 lb below hot I rely on them to tell me.

They didnt however go off on one tyre which delaminated but didnt go down.

They did go when one flicked the tread off and went down slowly

Lovely things Dunlop tyres.


Better to have them slightly inaccurate than not at all in my book

I have them on both the car and the van wouldnt be without them

G'day Everyone

Zacc ~ the Tyredogs are quite accurate, but as Graham H suggests the typical high use service station air pressure gauge is next to usless, for what would be an accurate pressure reading.

If you are very particular about your tyres and the pressures you choose to run them at, buy a good quality manual pressure gauge from a major tyre outlet, check the tyre pressure sensors against the gauge reading and it can still be anything up to 2 PSI out.

The modern technology tyre sensors are very accurate ~ but still have a small percentage error rate, not enough to be critical though.

The 4 PSI rule is a good measurement system also, it was in use long before any form of electronic pressure monitoring system.

The 4 PSI rule or method involves checking tyre pressures cold ~ then driving a prescribed distance ~ (X Kilometres ) or until the vehicle has reached normal operating temperatures ~ re check tyre pressures ~ if there is a rise of more than 4 PSI the initial pressure(s) readings, were low, to begin with.

It is not a complicated method, just time consuming, but once mastered, its simple and accurate.

Mr Jol Flemming ~ a four wheel drive training/tour operator advocates the tyre foot print method, this is also a good method of adjusting tyre pressures to the load and terrain. www.direct4wd.com.au Again a relatively simple but very accurate method of ~ pressure(s) x load x terrain.

The electronic monitoring system(s) are always monitoring and almost instant in feed back to the vehicle operator.

There is a minor problem with that method as I see it in that you do the measurements and have the car all nice.

THEN you hook the van on and suddenly everything changes. I reckon by looking at my tyre wear over 50,000k of towing mine are about right.

Tyres were new when started are now just over 1/2 worn.

Graham,

Yeh, well you do need to adjust the vehicles tyre pressures when you're towing! And you do need to do the hot tyre checks with the van hooked up. I know from previous experience what cold pressures to put in the Patrol and what cold pressures need to go in the van, and set it up that way before we leave.

We set off and at the first stop (usually mid-morning tea) I go round and recheck all the tyre pressures. I also check for any exceptional bearing temps as well. If the pressure increase is less than 4 psi I release the pressure accordingly.

If any tyre pressure has gone up more than 6psi I add more air at the first service station. If you have a compressor onboard you can do it right then and there, of course. Not that difficult really!

I use 6psi as the guide as I have fairly heavy tyres on both Patrol and van.

Why wait to see what the wear pattern on your tyres is, when you can check whether you have the right pressures within half an hour of setting off.

LES

If the pressure has gone up by 6psi why would you put more in ?

If they go up more than 6 there isnt enough in there to start with as if they are under-inflated they heat up and rise more


TO LES

You misread what I have said through the thread

I never said I waited 50,000k to see if the wear was right.

I stated early in the thread that I use the 6lb rule

Icheck oil and water EVERY morning and the tyres and bearings after about 30-45mins of driving

I said that AFTER 50,000k the wear showed that I had the pressures correct as evidenced by the wear on the tyres.

Who would wait 50,000k to check tyre wear.

Graham,

Yep, you're probably right - just as you've misread mine. I didn't say that you waited until you'd done 50k to check tyre wear. I was simply making the point that the pressure basis was a lot more immediate.

And I presume that your last question is rhetorical? Or is the subject of a new thread?

LES

No its not and you did say

"Why wait to see what the wear pattern on your tyres is, when you can check whether you have the right pressures within half an hour of setting off."

Only an idiot would do that.

I am well aware of the correct procedures and thats why my tyres have worn so well.

Graham,

I didn't reply to have an ongoing "you said, I said" dialogue with you.

We both agree that the 4psi/6psi approach is the correct one.

Let's leave it at that, please.

LES