You must mean supercharger, buick did not have a turbocharged model in 1997. If so, it is a special supercharger oil, available at a GM or Ford dealer (Mustangs use Eaton blowers too) or for about half of the cost on e-bay. It should be changed at around 100,000 miles. You will need a syringe or turkey baster to get the old oil out through the plug on the snout, no drain plug, then re-fill with around 6 ounces of new oil. BTW, the old stuff will stink to beat H*((, so you know. You might want to google "M90 coupler" as well if you hear even a little rattle in there...