1993 GMC Suburban Owner's Manual - Page 281

Thesenumbersonan oil containershowitsviscosity,orthickness. 1OW-40 or SAE 2OW-50. Do notuseotherviscosityoilssuchasSAE e Energy Conserving 81 Oilswiththesewords on thecontainerwillhelpyousavefuel. This doughnut-shaped logo(symbol) is used onmost oil containers to help you selectthecorrect oil. You should look forthis on theoilcontainer, displaythelogo. and use only those oilsthat requirements GM Goodwrench@ oil (in Canada,GMEngineOil)meetsallthe for your vehicle. Engine OD Additives: Don't add anything to your oil. Your GMdealer is ready to advise if youthink somethingshould be added. When to Change Engine Oil: See if anyoneofthese is trueforyou: Q Most tripsarelessthan 4 miles (6 km). 0 It's belowfreezingoutsideandmosttripsarelessthan10miles(16 km). Q Theengine is at low speed most of thetime(as delivery, or in stop-and-go traffic). You tow atraileroften. in door to door (Q * Most tripsarethroughdustyplaces. 8 Thevehicle is frequentlyoperatedoff-road. to changeyour oil Ifanyoneoftheseistrueforyourvehicle,thenyouneed and filter every 3,000 miles (5000 km)or 3 months-whichevercomesfirst. Vehicles with Light Duty Emissions (8580 GVWR or less). If none of them is true, changethe oil every 7,500 miles(12 500 km)or 12 months-whichevercomesfirst.Changethefilteratthefirst oil change and at every other oil change after that. Vehicles with Heavy Duty Emissions (8581 GVWW or more). If noneof them is true,change the oil every 6,000 miles (10 000 km) or 12 months-whichevercomesfirst.Changethe filter atthefirst oil changeandat everyother oil changeafterthat if mileagedetermineswhen you changeyour 6-1 5