Re: Hoosier tire pressure

[TeamM3@xxxxxxx]

I have been running Hoosiers radials on BMW's ever since they came out 
(1996).  No specifics were given regarding wheel sizes, suspension 
modifications, etc. so I can only speak in general.  Hoosier radials require 
much higher pressures than other tires.  My ideal hot pressures on SCCA Stock 
class E36 M3 and Z3 2.8 coupe are 58 - 60 psig front and 45 - 48 psig rear.  
Structurally, they will handle these pressures without need for concern.  
Most people struggle with this based on past experience with other tires, but 
that was with other tires, not this tire.  The construction on a Hoosier 
radial is WAY different than other tires.  Running at the lower pressures 
will result in decreased handling, excessive wear, and early cording, usually 
on the front outer corners.  The best way to determine the proper pressure is 
by watching outer tire corner rollover and scrub patterns.  If you allow a 
Hoosier radial to roll over too much onto the smooth area adjacent to outer 
edge of the tread surface (as viewed on a new tire) you will end up having 
significant wear issues.

No disrespect for your instructor, but these tires cannot be compared, to or 
run like, other brands.  You need to insist on running the correct pressures 
for these tires.  If they are not experienced with these tires then they are 
not qualified to tell anyone what pressure to run with them.  If you go to 
the Hoosier Care Tips page on the Tire Rack website you will see that 
vehicles weighing more than 3000 lb are recommended hot pressures 43 - 48+ 
psig (notice that the high end is 48-plus, the actual pressure required being 
dependent on tire size relative to rim size, amount of neg. camber, shock 
valving, vehicle weight, type suspension, etc.).

ps: the latest versions, A3S03 (autox) and R3S03 (road race) are much 
superior to the earlier S01 and S02 versions, with regard to wear and 
handling, due to construction and compound changes.  They are much more 
tolerant of minimal camber applications.

Mark Sipe

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