Q. I have a 2001 Buick Regal which, I understand, should take 4.5 quarts of oil on an oil change, not five quarts. Is the higher amount harmful to the engine? It does read considerably over the full mark on the dip stick when this happens.
A. You are correct on the oil capacity for your car; it is 4.5 quarts. If it is over filled by half a quart, it should not hurt anything, but I would take it back to the oil change shop and have the level adjusted to the proper level.
It is always hard to know exactly how much oil is too much, so it's best to get it right on the nose. While the oil level being exactly on the line is not as critical on your car, it is extremely critical on some of the newer vehicles. The oil level has to be right or it can set computer codes in newer models, and in fact some of the hybrids won't even start.
As long as we are talking about oil, let me use this opportunity to remind our readers not only of the importance of keeping the oil changed at the appropriate interval, but also of using the right oil. If you consult your owner's manual, it will tell you the amount and the viscosity of the oil your manufacturer requires in your car.
You should always use what the manufacturer recommends. If you want to move up to a full synthetic oil, this will be fine. However, if your car calls for a full synthetic, you don't want to move down to a blend.
Just remember, if you do your oil changes at the right interval, with the right kind and right amount of oil, you will be able to keep your vehicle for a long time!