Tyre pressures for AT20s ?

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

I got to drive my in-laws down the south coast of NSW (Jervis Bay) over the weekend in their new D4D GXL ... was great to have a decent test drive (although no offroad driving). Came back through Stanwell Park, and was impressed with how effortless the driving up some of those steep and winding hills was.

Anyway - there was a question about what tyre pressures to run in the standard AT20s that are shipped with the Prado for normal highway driving and normal load levels ?

I've read a few other threads about this topic, but wanted to see if there were a few more people who would let us know what they recommend ?

[Fazza Senior Member Find all posts View Profile Close Fazza]

Sim,
Tyre pressures, always good for discussion.

The vehicle manufactures & tyre companies go to great lengths to arrive at their suggested tyre pressures re- load, ride comfort, tyre foot print or contact area, impact damage etc.
So I would suggest that the vehicles tyre placard is what you should use, (found on the drivers door pillar) Placard reads 190 kp/28psi for all loads.

To low a pressure will cause outside edge wear, possible sidewall damage & tread separation.
To high a pressure will cause centre tread wear, harsh ride, possible impact damage to steel belting & star cracking inner casing.

After saying all of that I personally run my Dunlop AT20s' at 30 to 35psi depending on load.

More on tyres you could read some bulletins from Toyo Tyres
www.toyo.com.au Tech Info Bulletins. TT117, TT114, Inflation pressures for PCR & 2001 Toyo Tyres Mirage Series ? May 2001

Fazza D4D Auto with Dunlops

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

After saying all of that I personally run my Dunlop AT20s' at 30 to 35psi depending on load.

Any particular reason you choose to go higher than the recommendation on the vehicle ?

[Fazza Senior Member Find all posts View Profile Close Fazza]

Sim,
To answer you question.
The main reason I run those pressures is I do a fair amount of towing & have found the vehicle handles the extra load better & in the passed the front tyres appear to be wear better. (yet to be proven with this vehicle)

Fazza 07 Auto (With Dunlop AT 20s)

[Matt Senior Member Find all posts View Profile Close Matt]

i used to run 30-35 .. now i run 40... the tyres were getting chewed out on the lower pressure

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

I think the manufacturers prioritise 'comfort' high in their calculations at arriving at recommended tyre pressures.

Ever seen the 'advanced driving' demos they regularly do on tele... where they show the tyre under load during cornering and braking. The difference a higher presure makes is substaintial.

I run mine at 36psi for around town and highway.

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

I have owned my vehicle for 1-week (900kms) and finally got around to measuring the cold tyre pressure.

Within 0.5psi, each tyre was inflated to: 59psi :!: :!: .
[Edit: BTW, Max Tyre Pressure is stamped on the sidewall and is 51psi!]

Just to be sure my guage was not misreading, I verified it with a bicycle-pump with an in-built guage.

Holy crap! No wonder so many GrandTrek tyres get such poor wear.

A $15 tyre-guage is well worth the investment! (I wish I had it with me when I was collecting the vehicle from SciFleet).

I'll reset them to 40psi. That will probably take some of the roughness out of the ride. Up until now, I've been blaming the firmer suspension.

LFaR.