1994 Chevrolet Blazer Owner's Manual - Page 248
1994 Chevrolet Blazer Manual
Page 248 highlights
SHorSG "SH" or "SG" must be on the oil container, either by itself or combined with other quality designations, such as "SH/CD," "SH, SG, CD," "SG/CD," etc. These letters show American Petroleum Institute (API) levels of quality. SAE 5W-30 Energy Conserving I1 Oils with these words on the container will help save fuel. you These three things are usually included in a doughnut shaped logo (symbol) on most containers. If you cannot find oils with the "starburst"symbol, you should look for oils with the doughnut shaped symbol, containing the three things noted above. NOTICE: If you useoils that do not have either the "starburst" symbol or an API SH or SG designation, you can cause engine damage not covered by your warranty. GM Goodwrench@oil (in Canada, GM Engine Oil) meets all the requirements for your vehicle. Engine Oil Additives Don't add anything to your oil. Your GM dealer is ready to adviseif you think something should be added. 6-12