2014 Cadillac XTS Owner Manual - Page 244

9-58 Driving and Operating { Warning LDW does not provide a warning to help avoid a crash, unless it detects the lane markings. LDW may not detect the lane markings if the camera sensor is blocked by dirt, snow, or ice, or if the windshield is damaged. It may also not detect a lane on winding or hilly roads, or in conditions that can limit visibility such as fog, rain, or snow, or if the headlamps or windshield are not cleaned or in proper condition. Keep the windshield, headlamps, and camera sensors clean and in good repair. LDW warnings may occur due to tar marks, shadows, cracks in the road, or other road imperfections. This is normal system operation; the vehicle does not need service. Fuel Use of the recommended fuel is an important part of the proper maintenance of this vehicle. To help keep the engine clean and maintain optimum vehicle performance, we recommend using TOP TIER Detergent Gasolines. See www.toptiergas.com for a list of TOP TIER Detergent Gasolines. octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when driving. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service. If the vehicle has the 3.6L V6 LF3 twin turbo engine (VIN Code 8), use premium unleaded gasoline with a posted octane rating of 91 or higher. If the octane is less than 91, you could damage the engine and may void your vehicle warranty. If heavy knocking is heard when using gasoline rated at 91 octane or higher, the engine needs service. Use of Seasonal Fuels Use summer and winter fuels in the appropriate season. Driving or starting could be affected if the incorrect fuel is used. Drive the vehicle with the engine running until the fuel is a half tank or less, then refuel with the current seasonal fuel. If the vehicle has the 3.6L V6 LFX engine (VIN Code 3), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the