2008 Toyota Tundra Owners Manual - Page 478

07 11.20 Facts about engine oil consumption D Do not leave the engine running in an area with snow build−up, or where it is snowing. If snowbanks build up around the vehicle while the engine is running, exhaust gases may collect and enter the vehicle. This may lead to death or a serious health hazard. always turn the engine off. Otherwise, you may accidentally move the shift lever or depress the accelerator pedal, which could cause an accident or fire due to engine overheating. Additionally, if the vehicle is parked in a poorly ventilated area, exhaust gases may collect and enter the vehicle, leading to death or a serious health hazard. D Toyota does not recommend occupying the rear cargo area when it is fitted with a slide−in camper, camper shell or other type cover while the engine is running. This caution applies to both driving and stopped or parked situations with the engine running. Particular care should be taken to prevent exhaust gases from entering camper bodies, trailers or other enclosures on or around your vehicle. If exhaust fumes are detected, open all windows and thoroughly ventilate the area. FUNCTIONS OF ENGINE OIL Engine oil has the primary functions of lubricating and cooling the inside of the engine, and plays a major role in maintaining the engine in proper working order. ENGINE OIL CONSUMPTION It is normal that an engine should consume some engine oil during normal engine operation. The causes of oil consumption in a normal engine are as follows. D When taking a nap in the vehicle, D Oil is used to lubricate pistons, piston rings and cylinders. A thin film of oil is left on the cylinder wall when a piston moves downwards in the cylinder. High negative pressure generated when the vehicle is decelerating sucks some of this oil into the combustion chamber. This oil as well as some part of the oil film left on the cylinder wall is burned by the high temperature combustion gases during the combustion process. D Oil is also used to lubricate the stems of the intake valves. Some of this oil is sucked into the combustion chamber together with the intake air and is burned along with the fuel. High temperature exhaust gases also burn the oil used to lubricate the exhaust valve stems. 448 2008 TUNDRA from Apr. '08 Prod. (OM34477U)