Choose Mobil 1™ motor oil for your Sterling
The use of Mobil 1 motor oil will not void new-car warranties where an American Petroleum Institute (API) certified oil is recommended. The exception is the Mazda rotary engine (Mazda does not recommend any synthetic oils). Always consult your owner’s manual.
The instructions are very easy to follow: Simply change the oil as you would normally. Any “confusion” is just myth. You can switch from conventional motor oil to Mobil 1™ synthetic oil (and back again, if you want) without following any special procedures.
However if your vehicle has a higher-mileage engine that has never used synthetic motor oil, or one that has been poorly maintained with infrequent oil changes, we recommend easing into extended drains to allow Mobil 1 to clean up the engine. In these cases you should still follow the same basic oil-change procedures (drain the old oil, remove the old oil filter, put in new Mobil 1 motor oil and put on a new oil filter). Follow your OEM’s recommended maintenance practices regarding oil changes, but you should follow more frequent (one or two non-extended drain) oil changes when first switching to synthetic oil.
The reasoning behind these shortened oil drain intervals is that a high-mileage engine, or one that has had a lack of maintenance including infrequent oil changes, will likely have a considerable buildup of sludge and deposits. Mobil 1 motor oil will help clean the engine as you drive, but it will have to work much harder in a very “dirty” engine, and so it is best to change the oil more frequently for those first several thousand miles. After that, you can rest assured that Mobil 1 synthetic oil is continuing to keep your engine running clean and well lubricated for mile after mile.