Acura 2011 RL Owner's Manual page 490

Tires
Tire Inspection
Every time you check inflation, you
should also examine the tires for
damage, foreign objects, and wear.
You should look for:
Bumps or bulges in the tread or
side of the tire. Replace the tire if
you find either of these conditions.
Cuts, splits, or cracks in the side
of the tire. Replace the tire if you
can see fabric or cord.
Excessive tread wear.
484
INDICATOR LOCATION MARKS
TREAD WEAR INDICATOR
Your tires have wear indicators
molded into the tread. When the
tread wears down, you will see a 1/2
inch (12.7 mm) wide band across the
tread. This shows there is less than
1/16 inch (1.6 mm) of tread left on
the tire.
A tire this worn gives very little
traction on wet roads. You should
replace the tire if you can see three
or more tread wear indicators.
Tire Service Life
The service life of your tires is
dependent on many factors,
including, but not limited to, driving
habits, road conditions, vehicle
loading, inflation pressure,
maintenance history, speed, and
environmental conditions (even
when the tires are not in use).