Kenworth T410, Driver'S Handbook Manual

Page: 217 / 418

CAT: 8612 November 2019 Page 191
OPERATING INSTRUCTIONS
City Driving — Cruising
Operate the engine in the preferred rpm range to obtain optimum
performance, and reduce stresses and wear. Avoid lugging the engine
for any extended period of time as this reduces engine life. Consult your
engine manufacturer’s operation manual for the preferred operating range.
Observe the tachometer and operate the engine within its economical
rpm range with a minimum of gear shifting. It is not necessary to keep the
engine revving in its high rpm range.
Cruise at partial throttle whenever conditions permit. When approaching
an uphill grade, smoothly apply full throttle so that the climb will be started
at full power. Downshift as necessary to maintain vehicle speed without
lugging the engine.
For your particular engine and operating conditions refer to the engine
manufacturer’s operating manual.
INSTRUCTIONS TO PREVENT JACKKNIFING
Most truck and semi-trailer jackknifes occur when the roads are wet and
the semi-trailer is unladen.
This is because the drive tyres will skid much more easily when there is
water between the tread and the road surface.
Also, when the semi-trailer is unladen (50% of the time with tankers and
tippers), there is less weight on the drive tyres so less brake pedal travel
is required to lock the brakes.
Awareness that wet weather and empty load combination is the most
dangerous condition will be sufficient for good drivers to avoid jackknifing.
However, there are also several other factors which should concern drivers
and operators since they also influence brake balance and tyre adhesion
and hence the possibility of jackknife. The following is a list of these items:
1. Tyre tread pattern must be adequate to remove water under wet
conditions. This is particularly important on drive tyres. Rib tread
patterns are substantially better than lug type.
2. Tyre tread depth must be sufficient to get water out from under
most of the tyre contact patch (3 mm is the minimum tread depth
for truck tyres).