1998 GMC Suburban Owner's Manual - Page 366

I KEEP ENGINE OIL AT THE PROPER LEVEL AND CHANGE AS RECOMMENDED IMPORTANT: I Introduction Your Vehicle and the Environment Proper vehicle maintenance not only helps to keep your vehicle in good working condition, but also helps the environment. All recommended maintenance procedures are important. Improper vehicle maintenance can even affect the quality of the air we breathe. Improper fluid levels or the wrong tire inflation can increase the level of emissions from your vehicle. To help protect our environment, and to keep your vehicle in good condition, please maintain your vehicle properly. How This Section is Organized The remainder of this section is divided into five parts: "Part A: Scheduled Maintenance Services" shows what to have done and how often. Some of these services can be complex, so unless you are technically qualified and have the necessary equipment, you should let your dealer's servicedepartment or another qualified service center do thesejobs. 7-2