1994 Buick Regal Owner's Manual - Page 220

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. 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 Buick dealer is ready to advise if you think something should be added. When to Change Engine Qil See if any one of these is true for you: 0 Most trips are less than 4 miles (6 km). 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-to-door delivery, or in stop-and-go traffic). You tow a trailer often. Most trips are through dusty places. 0 0 0 I NOTICE: If you use oils that do not have either the "starburst" symbolor an API SH or SG designation, you can cause engine damage not covered by your warranty. 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 km) 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. 218