QUESTION: What type of engine oil should I use in my car?
I never asked the dealer when I took the car there, but recently started to use one of those quickie places that offer all different brands. They asked me what type I wanted to use and I didn't know the answer. - Tim
ANSWER: This is an easy one. Use the oil recommended by the manufacturer.
Look in the owner manual and it will be specific as to weight and SAE (Society of Automotive Engineers) specification.
All major oil companies will have at least one grade of oil that meets those specifications and any of them will do.
Oil not only acts as a lubricant, it also cools and cleans, carrying heat away from the hottest parts of the engine and tiny little particles caused by wear, which are trapped in the filter.
The car maker designed and developed the engine in your car around certain standards and any oil that meets them will suffice.
It is more important to change your oil according to the service schedule recommended by the manufacturer than try to extend those intervals in the false belief you can go longer on "better" oil.
Be careful to read the recommended oil change intervals carefully.
You will probably find that if you primarily operate the vehicle for short runs of only a few kilometres, on a dirt road or in dusty conditions, the recommendations will be for a more frequent change interval.
As the oil travels throughout the engine, it picks up some nasty chemicals and gases that are burned off when it reaches full operating temperature.
It also may contain some moisture created by the contact between hot and cold surfaces. You probably have noticed the steam coming from a cold exhaust or some moisture dripping from an exhaust pipe.
If you only make short trips, the exhaust may not get up to a temperature sufficient to evaporate this moisture and burn off those corrosive nasties, leaving all that in the oil to perhaps cause damage.
As for the dust, tiny little particles may find their way into the engine, causing wear, or coming into contact with the oil, which will carry them to the filter.
Changing the oil more often in these conditions ensures the oil is able to do its job.