G
Guest
Guest
Mik wanted to know about the old 4psi tyre setting routine, so here it
is.......
So, the manufacturer's calculated optimum pressures when warm are nearly
always 4psi above the recommended pressure when cold. You inflate to 32 and
when warm they are 36psi, and that's where Mr Dunlop/BFG/General et
al. wants them to be.
So if in doubt, set them to 32 early in the morning before it gets any heat
of the day, go for a ride for half an hour, and not in stop-go traffic, but
you don't have to do the Schumacker wiggly steering though. Then test the
pressure. If its 36 then you have it right. If its 38 and the car is full
of kids Labradors and chainsaws then it should be 34 cold for those loading
conditions. Likewise if its 34 when warm, then you should run at 30psi
cold. But in summer when its hot and you are going on a long autoroute
drive then inflate the rears more to get the best fuel consumption etc. The
only exception I have found is when it gets very - 40 degs - hot in summer
the fronts tend to squeal on tight corners and I put another 2psi in to
quieten them.
It is said that no 4WD car should run at much above 35psi otherwise the
tyres can't mould around the surface to get grip. But I am sure that it can
be proven otherwise by someone !
By the way, someone wrote less than affectionately about Dunlop Grand
Treks. Toyota have fitted them as OEM for years. My 80 has always worn TG
35 M2 pattern on 265/70 X 16's. I am amazed at the grip and wear I get from
them in very exceptional and varied conditions in a wide range of
temperatures, from minus 30 to plus 40. Even on the high speed tarmac roads
they are well behaved. I think I will replace them in respect of their
perishing rather than wear. (Maybe when Julian sees them next week he can
give me another opinion.) Each to his own I guess.
Jon
'92 HZJ80 ex UN surplus from Bosnia, now sharing time between Alfold Surrey
and Tring Herts.
is.......
So, the manufacturer's calculated optimum pressures when warm are nearly
always 4psi above the recommended pressure when cold. You inflate to 32 and
when warm they are 36psi, and that's where Mr Dunlop/BFG/General et
al. wants them to be.
So if in doubt, set them to 32 early in the morning before it gets any heat
of the day, go for a ride for half an hour, and not in stop-go traffic, but
you don't have to do the Schumacker wiggly steering though. Then test the
pressure. If its 36 then you have it right. If its 38 and the car is full
of kids Labradors and chainsaws then it should be 34 cold for those loading
conditions. Likewise if its 34 when warm, then you should run at 30psi
cold. But in summer when its hot and you are going on a long autoroute
drive then inflate the rears more to get the best fuel consumption etc. The
only exception I have found is when it gets very - 40 degs - hot in summer
the fronts tend to squeal on tight corners and I put another 2psi in to
quieten them.
It is said that no 4WD car should run at much above 35psi otherwise the
tyres can't mould around the surface to get grip. But I am sure that it can
be proven otherwise by someone !
By the way, someone wrote less than affectionately about Dunlop Grand
Treks. Toyota have fitted them as OEM for years. My 80 has always worn TG
35 M2 pattern on 265/70 X 16's. I am amazed at the grip and wear I get from
them in very exceptional and varied conditions in a wide range of
temperatures, from minus 30 to plus 40. Even on the high speed tarmac roads
they are well behaved. I think I will replace them in respect of their
perishing rather than wear. (Maybe when Julian sees them next week he can
give me another opinion.) Each to his own I guess.
Jon
'92 HZJ80 ex UN surplus from Bosnia, now sharing time between Alfold Surrey
and Tring Herts.