Operation, maintenance -> Tire condition for your BMW 3 Series 1997-2006

Wheels and tires  
Tire inflation pressure  
Tire condition  
115  
wall with TWI – Tread Wear Indicator. At  
Information for your safety  
a tread depth of 1/16 in / 1.6 mm, the  
indicators signal that the legally permis-  
sible wear limit has been reached.  
The factory-approved tires are matched  
to your vehicle and have been selected  
to provide optimum safety and driving  
comfort when used properly.  
Do not drive on a deflated – flat –  
tire. A flat tire greatly impairs  
steering and braking response, and can  
lead to complete loss of control over  
the vehicle.  
It is not merely the tire's service life, but  
also driving comfort and – above all else  
– driving safety that depend on the con-  
dition of the tires and the maintenance  
of the specified tire pressure.  
Avoid overloading the vehicle so that  
the permitted load on the tires is not  
exceeded. Overloading can lead to  
overheating and internal tire damage.  
You could have a blowout as a result.  
Unusual vibrations encountered during  
normal vehicle operation can indicate  
tire failure or some other vehicle defect.  
This type of problem can be caused by  
contact with curbs, etc. This is also true  
for irregularities in the vehicle's han-  
dling characteristics, such as a pro-  
nounced tendency to pull to the left or  
right. Should this occur, respond by  
immediately reducing your speed. Pro-  
Incorrect tire inflation pressure is  
a frequent cause of tire damage. It  
also significantly influences the road-  
holding ability of your BMW. Check tire  
inflation pressures on a regular basis,  
refer to page 25, at least every two  
weeks and before beginning a longer  
trip. Incorrect tire pressure can other-  
wise lead to driving instability, tire dam-  
age and accidents.<  
Tire tread – tire damage  
Inspect your tires frequently for tread  
wear, signs of damage and for foreign  
objects lodged in the tread. Check the  
tread depth.  
Tread depth should not be allowed to  
go below 1/8 in / 3 mm, even though  
the legally specified minimum tread  
depth is only 1/16 in / 1.6 mm.  
Below 1/8 in / 3 mm tread depth, there  
is a great risk of hydroplaning, even at  
relatively moderate speeds and with  
only small amounts of water on the  
road. Tread wear indicators in the  
tread-groove base – see arrow – are  
distributed around the wheel circumfer-  
ence and are labeled on the tire side-  
116 Tire condition  
Tire replacement  
ceed carefully to the nearest BMW cen-  
ter or professional tire center, or have  
the vehicle towed in to have it, its  
wheels or its tires inspected.  
Tire damage, up to and including blow-  
outs, can endanger the lives of both the  
vehicle occupants and other road  
users<  
Those grades represent the tire's ability  
to stop on wet pavement as measured  
under controlled conditions on speci-  
fied government test surfaces of  
asphalt and concrete. A tire marked C  
may have poor traction performance.  
DOT quality grades  
>Treadwear  
>Traction AA A B C  
>Temperature A B C  
All passenger car tires must con-  
form to Federal Safety Require-  
ments in addition to these grades.<  
The traction grade assigned to  
this tire is based on straight-  
ahead braking traction tests, and does  
not include acceleration, cornering,  
hydroplaning, or peak traction charac-  
teristics.<  
Tread wear  
The treadwear grade is a comparative  
rating based on the wear rate of the tire  
when tested under controlled condi-  
tions on a specified government test  
course.  
Temperature  
The temperature grades are A – the  
highest – B and C, representing the  
tire's resistance to the generation of  
heat and its ability to dissipate heat  
when tested under controlled condi-  
tions on a specified indoor laboratory  
test wheel.  
For example, a tire graded 150 would  
wear one and one-half – 1 1/2 – times as  
well on the government course as a tire  
graded 100. The relative performance  
of tires depends upon the actual condi-  
tions of their use, however, and may  
depart significantly from the norm due  
to variations in driving habits, service  
practices and differences in road char-  
acteristics and climate.  
Sustained high temperature can cause  
the material of the tire to degenerate  
and reduce tire life, and excessive tem-  
perature can lead to sudden tire failure.  
The grade C corresponds to a level of  
performance which all passenger car  
tires must meet under the Federal  
Traction  
The traction grades, from highest to  
lowest, are AA, A, B and C.  
Motor Vehicle Safety Standard No. 109.