Tyre Pressure question?

[Guest Close Guest]

Hi all, have a new Prado purchased last month with the Dunlop 265/65's, went to check the pressure (230kpa) and it was a lot higher than the recommended pressure which is 190kpa.

The service dept says the higher pressure is better for the wear of the tyre but you'll have a more bumpier ride.

Anybody found the best pressure for these tyres in terms of comfort/wear and more importantly fuel economy?

Thanks
Steve

[lc120_man Advanced Member Find all posts View Profile Close lc120_man]

I ran mine on 38 PSI (not sure what is Kpa equivalent is).
Some run 36 front, 38 rear....

[Drew Advanced Member Find all posts View Profile Close Drew]

G'day Steve,

I run Cooper ATRs on my 120. I've been experimenting with a couple of different pressures and have found that 34psi is a good balance. The placard suggest something like 29psi :shock: they are way too baggy at that pressure. My tyre bloke initially tried 38psi but I found the ride too harsh and they seemed to squeal more on the twisties at this pressure.

Hope this helps some.

Drew.
8)

[Peter Junior Member Find all posts View Profile Close Peter]

Hey guys,

Currently running all 4 on 38psi.

What do you run them on the sand? I started with mine at 22 but was getting bogged a lot in the sand. So now I run them at 18 when on the sand.

I always get nervous at this level but the tyres seem to perform well on the beach.

[Chuck Advanced Member Find all posts View Profile Close Chuck]

A lot depends on what brand of tyres you are running and the size.
I currently have a 90 Series with 225/75R16 and run them at 35psi Hwy, 40psi Rears towing and 25psi on the beach with out any problems.

My previous tyres were a different brand and ran at different pressure on the beach you needed to get down to 18psi to stop getting bogged.

[samo Addicted PP Member Find all posts View Profile Close samo]

i have 265s on me gx and on the black i run 36psi and when on the beach i run around 15psi down to 12 in the soft stuff

[Bomber-74 Member Find all posts View Profile Close Bomber-74]

I read somewhere about a 4psi rule.

Air up your cold tyres and then go for a drive until your tyres are up to operating temp. Check your pressures and the difference from cold should be 4psi higher.

If it is higher than that your pressures are too low - increase cold tyre pressure

If it is lower then your pressures are too high - decrease cold tyre pressure

Off road it is terrain dependent.

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

i run the 694's at 36 front and rear, 22 sand, if it is soft ie Nagala rocks at fraser it was 16 psi just to get through.
36 seems a good balance around town comfort and wear and Bombers theory works at around this pressure they go up to about 39-40 when they are hot.

[Jon Avid PP Poster! Find all posts View Profile Close Jon]

I run my Cooper ATR's at 40PSI, which is what the tyre dealer recommended. Car is always loaded with parts & tools or camping gear (not often enough!). Have OME suspension.
I am now on my second set of Coopers, easily get 80,000KM with very little wear on the edges of the tyres.
Run them at 30PSI off road, 15-20PSI on sand ( ran at Fraser 20PSI no problems...had to rescue others running at 40 PSI - until I educated them; had to be down to 15PSI on Simpson Desert)

[KMKPrado Member Find all posts View Profile Close KMKPrado]

tyre pressures

I run BFG T/A's on the highway at 40psi, sand 18psi front and rear, dirt tracks 30psi. 71,000km's on them so far and still have approx 40-50% of tread left.

[Justo Advanced Member Find all posts View Profile Close Justo]

I'm about the same as Jon. Running on Cooper ATR's at 40 PSI. No hassles with edges wearing and generally around 18 PSI in sand, but had to drop em to 9 or 10 once to get out of some really soft sand. I keep an eye on them, if they eventually start to wear the centre of the tread out I'll drop the pressure a bit.

[goanna Junior Member Find all posts View Profile Close goanna]

I just recently had 4 new Cooper ST's fitted here in Canberra. I was taking it off road next day so didn't get a chance to check the pressures till i was ready to drop them, glad i did as all 4 had about 50psi in them!! I do alot of highway driving but i new that was way to high, i now have them about the 39-40 mark. Ride seems fine.

[wengnuts Advanced Member Find all posts View Profile Close wengnuts]

I just recently had 4 new Cooper ST's fitted here in Canberra. I was taking it off road next day so didn't get a chance to check the pressures till i was ready to drop them, glad i did as all 4 had about 50psi in them!! I do alot of highway driving but i new that was way to high, i now have them about the 39-40 mark. Ride seems fine.

Be sure to follow the tyre pressure guideline as stipulated in your warranty card otherwise Cooper will void your tyre warranty.

[Guest Close Guest]

I ran mine on 38 PSI (not sure what is Kpa equivalent is).
Some run 36 front, 38 rear....

38psi equals 262kPa

http://www.csgnetwork.com/presskpapsicvt.html

which is 38% (!) or 10.5psi above recommended pressure on the placard 190kPa/27.5psi.

From the Cooper Tyre Brochure (but hey - what would they know):
"If your tyres are over-inflated by as little as 6 psi, they could be damaged more easily when driving over potholes or debris on the road. Over inflation also causes tyres to wear in the centre of the tyre's tread which will reduce the tread life. Higher inflated tyres will also give you a much harsher ride."

Have you tried the "4-psi-rule" [Bitumen Road Use Only !] where there difference between a cold and hot tyre should be 4 psi?

If difference is more than 4 psi, add pressure when tyre is cold
- if the difference is less, deflate when cold.

[Guest Close Guest]

Well I thought I put a bit of science into the discussion.

Your logic of "27.5 psi on a craptrek is fine" does not follow as the example was explicitly for BITUMEN and any other surface cries for LOWER rather than higher pressure.

Your reply reads like "I/we know best" without giving any reason - each to their own.