All modern internal combustion engines use some type of oil. Oil does several jobs. The most important one is to lubricate moving parts to reduce friction. Reducing friction is very important in promoting fuel economy and engine life. Oil also cleans the inside of the engine, helps cool the engine, helps to seal the combustion chamber and keeps worn metal and other particles suspended to keep deposits (sludge) from forming. Long ago engine oil was made of just refined mineral oil. Now it consists of several blends of additives. Additives help the oil do its job and make it last longer. Synthetic oils usually contain some mineral oil but have a more aggressive additive package. Some vehicles require the use of synthetic oil for the better lubrication it can provide. Diesel engines require a different type of oil due to their different design of combustion. All oils wear every time an engine is ran. Worn metals, acidic byproducts from internal combustion and water condensation mix with the oil. All modern vehicles have an oil filter to help filter out the larger particles. As oil wears it looses its ability to do it’s job. Worn oil slowly leads to reduced engine performance, fuel economy, forming of sludge and faster engine wear. This means that oil should be changed on a regular basis. The more around town and stopping and starting done, the quicker oil needs to be changed. GM has a system on most 2004 and later vehicles that senses driving conditions and warns when oil should be changed. We recommend the oil and oil filter be changed between 3000 and 5000 miles whether the light has come on or not. This system will warn some drivers to change their oil quicker due to driving habits. If an engine oil system does get contaminated either from lack of proper oil change or mechanical failure, we have a flush service that does a very good job of getting it out. This service flushes a strong oil and detergent product through all the oil passages and then replaces it with clean engine oil. The success of this flush depends on how bad the contamination is and how much excessive wear it has caused.