2001 Toyota Land Cruiser Owners Manual - Page 186

'01 L/C U (L/O 0008) Iridium −tipped spark plugs As an example, if a vehicle is used for repeated short trips, and consumes a normal amount of oil, the dipstick may not show any drop in the oil level at all, even after 1000 km (600 miles) or more. This is because the oil is gradually becoming diluted with fuel or moisture, making it appear that the oil level has not changed. The diluting ingredients evaporate out when the vehicle is then driven at high speeds, as on an expressway, making it appear that oil is excessively consumed after driving at high speeds. IMPORTANCE OF ENGINE OIL LEVEL CHECK One of the most important points in proper vehicle maintenance is to keep the engine oil at the optimum level so that oil function will not be impaired. Therefore, it is essential that the oil level be checked regularly. Toyota recommends that the oil level be checked every time you refuel the vehicle. Your engine is fitted with iridium−tipped spark plugs. For detailed information on oil level check, see "Checking the engine oil level" in Section 7−2. NOTICE Use only iridium−tipped spark plugs and do not adjust gaps for your engine performance and smooth drivability. NOTICE Failure to check the oil level regularly could lead to serious engine trouble due to insufficient oil. 182