Mercury 1996 Grand Marquis Manual page 197

Driving While You Tow
Be especially careful when driving while you
tow a trailer. Never drive faster than 45 mph
(70 km/h) when you tow in hilly country on
hot days. Also, anticipate stops so that you can
brake gradually.
When you tow down steep grades, move the
gearshift to 1 (Low). It gives more engine
braking to slow your vehicle than Drive on the
downgrades.
If you tow in D (Overdrive) while riding
through hilly country, your vehicle may
frequently shift between Overdrive and Third
gears. To prevent your vehicle from shifting too
much, press the Transmission Control Switch
located on the shift lever. This will also give the
engine more power going up hills and better
engine braking going down hills.
If you use the speed control while you are
towing on very long, steep grades, the speed
control may shut off.
Servicing your vehicle if you tow
If you tow a trailer for a long distance, your
vehicle will need to be serviced more frequently
than usual. Refer to the Maintenance Schedule and
Record booklet for additional information.
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