2004 Cadillac DeVille Owner's Manual - Page 284

CAUTION: (Continued) Fuel Use of the recommended fuel is an important part of the proper maintenance of your vehicle. • Be sure you have sufficient knowledge, experience, the proper replacement parts and tools before you attempt any vehicle maintenance task. Be sure to use the proper nuts, bolts and other fasteners. "English" and "metric" fasteners can be easily confused. If you use the wrong fasteners, parts can later break or fall off. You could be hurt. Gasoline Octane Use regular unleaded gasoline with a posted octane of 87 or higher. However, for best performance and for trailer towing, you may wish to use middle grade or premium unleaded gasoline. If the octane is less than 87, you may get a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you might damage your engine. • Adding Equipment to the Outside of Your Vehicle Things you might add to the outside of your vehicle can affect the airflow around it. This may cause wind noise and affect windshield washer performance. Check with your dealer before adding equipment to the outside of your vehicle. 5-4