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Onroad pressures
Posted: Wed Mar 30, 2005 8:12 pm
by Syzygy
just got some 32" MTR's on my bundera and have no idea what pressure i should be running onroad...
i've got 33psi in them atm, the guy who fitted them put 36 in them.
I havn't driven on tyres like these before and i'm finding them a little more unpredictable than i expected... they are seeming to understeer or 'walk' on slight turning but if i turn more sharply they seem to really dig in and lurch the car more than expected. is this normal for the tyres and is it pressure dependent?
also finding them much noiser than i expected on cornering. It's like i'm hearing the tyres wearing away everytime i turn
Very happy with the noise on straight driving though.
Posted: Wed Mar 30, 2005 8:45 pm
by EricB
I found 36 on road to be nice without too much movement
Posted: Wed Mar 30, 2005 9:06 pm
by -Scott-
Without knowing your vehicle (and hence it's weight) it's difficult to speak from experience.
The characteristics you describe sound like your tyres are under-inflated. During initial turn-in you're bending sidewalls rather than turning. Then when you pull sharper nothing is left to give, and it lurches around. The noise behaviour also suggests you're running too much on your side lugs during turns.
FWIW, I run my 285/75-16 MT/Rs at 38psi, in a 4by with a 1700kg kerb mass. 2wd on dirt understeers terribly, but 4wd handles pretty nice. 2wd on bitumen strikes me as pretty good, considering my suspension setup.
Cheers,
Scott
Posted: Thu Mar 31, 2005 2:53 am
by ISUZUROVER
From my experience I found my MTR's to be a very soft, flexible tyre, and needed to be inflated quite high to have good road manners. I run my 285/75-16's at 40-45psi on road (on a Land Rover - about 1900kg). At high pressures though they have better handling and traction on bitumen than my 235/85-16 road tyres.
Posted: Thu Mar 31, 2005 10:30 pm
by bruiser
I reckon anywher from 32 - 40.
Closer to 40 and you will get better wear out of the tyre. leas traction and rougher ride
Closer to 30 and you will get a beter ride and grip on the road but you will tend to wear them premature especially on the edges unless you take all cornes at 5 k's/hr
I run 38
Posted: Sat Apr 02, 2005 11:45 am
by Bingham
as an aside ----correct me if im wrong but on mtrs 33 and 35's max pressure 35psi....
i ran at 30 both of these with no dramas...... run claws now at 28
Posted: Sat Apr 02, 2005 11:56 am
by plowy
most recomend 32 psi a good pressure to run
Posted: Sat Apr 02, 2005 12:17 pm
by dwaynes
i run mine at 38psi anything lower i get the dreaded wobble
Posted: Sat Apr 02, 2005 12:20 pm
by blkmav
36 dead cold which is about 40 hot
Posted: Sat Apr 02, 2005 1:45 pm
by BIG GQ
Dont ask me for an opinion cause I'm so farken lazy I'll quite opten drive the 37" claws at 10-12psi on the road
Posted: Sun Apr 03, 2005 7:53 am
by Gobbles
i do what blkmav does run them at 36 so when driving they expand to 40......
Is it a higher tyre pressure that increases Tread wear or a lower one becasue there is more surface area?
Posted: Sun Apr 03, 2005 8:55 am
by MARKx4
When i had my 33" MTR's i ran them at 35psi cold tempture and that was ok for my MK shorty.
Posted: Sun Apr 03, 2005 8:56 am
by Bartso
Bingham wrote:as an aside ----correct me if im wrong but on mtrs 33 and 35's max pressure 35psi....
i ran at 30 both of these with no dramas...... run claws now at 28
i run mine at 40 mate better wear
Posted: Sun Apr 03, 2005 10:36 am
by -Scott-
Gobbles wrote:i do what blkmav does run them at 36 so when driving they expand to 40......
Is it a higher tyre pressure that increases Tread wear or a lower one becasue there is more surface area?
If pressure is too low you'll wear the shoulders but not the middle of the tread.
If pressure it too high you'll wear the centre of the tread but not the shoulders.
If pressure is just right you'll wear them evenly - unless your driving style or wheel alignment comes into play.
Cheers,
Scott