Buick 1993 Roadmaster Owner's Manual page 254

It's below freezing outside and most trips are less:
than 10 miles (16 km).
.
The engine is -at low .speed most
of
the time (as in
door
tp
door delivery, or in stop-and-go traffic).
You tow a trailer often.
Most trips are through dusty places.
If -any one of these is true for your vehicle, then you
need-to change your oil.and filter every 3,000 miles
(5 000 k m ) or, 3 months - whichever comes first.
If none of them is true, change the oil every 7,500 miles
(12 -500
km) or 12 months - whichever comes first.
Change the filter at the first oil change and at every
other oil change after that.
Engine Block Heater: An engine block heater can be a
big help if-you have to park outside in very cold
weather, -20
*
F (-29 C ]
or .colder. I f your vehicle has
this option, see "Engine Block Heater" in the Index.
What to Do with Used Oil:
Used engine oil contains things that have
caused skin cancer in laboratory animals. Da
let used oil stay on your skin for very long
Clean your skin and nails with soap and water,
away clothing or rags containing used engine
0
lr a good hand cleaner. Wash or properly throw
I
. .
Used oil can be a real threat to the environment. If you
change your
own
oil, be sure to drain all free-flowing oil
Erom the filter before disposal. Don't ever dispose of oil
by pouring it on the ground, into sewers, or into streams
or bodies of water. Instead, recycle it by taking it.to a
place that collects used oil. If you have a problem
properly disposing of your used oil, ask your dealer, a
service station or a local recycling center for help.
252