Determining the length of time the oil should stay in the engine, is a little tricky. This is due to the fact that, it mostly depends on how the car is used, what conditions the vehicle is exposed to and the driving habits of the owner. We all know that these factors vary from person to person. Meaning, if your use the car in a certain way there are specific instructions as to how often you should drain the oil. Our goal is to be able to categorize and identify these.
First, let’s establish why it is important to do so. Contaminants, do, accumulate in the oil. Oil is also prone to certain chemical changes like oxidation and additive depletion. These two reasons alone, prevent it from doing its job of lubrication and an as a coolant. The longer you drive a car, the more contaminants it accumulates. The increase of these depend on several factors like the mechanical condition of the engine, the owner’s driving habits, air cleaner service, and carburetion adjustments. Oil filters must be replaced regularly in order to slow down the deterioration process. To further clarify, oil doesn’t wear out but the additives responsible for making it function are the ones that get depleted. New oil and filter will make the engine last longer and maintain the car’s good performance.
The American Petroleum Institute says that this change should be done at “regular intervals” and check with the recommendations given in your car’s service manual. Usually, there are two types: one for mileage which, in most cars is as around 3,000 miles; and the other one is for time, at around three months. When it’s summer time decrease the recommendation by 10% and by winter 20%. For example, in winter the oil must be changed around 2,400 miles. This is the computation for maximum oil-change intervals. It might be a bit costly and inconvenient for some, but you are assured that the car is in good condition when you need it to be.
These suggestions should only be used a basis for when you should change the oil. Take it with a grain of salt. If you have an upcoming cross-country trip where you expect to travel around 7,000 miles, it is not practical to have your oil change every 2,700 miles in the summer. Granting that ideal conditions are present like well-paved roads, high speed driving and clean highways, then you can make an exemption. If luck isn’t on your side and an encounter with a bad dust storm occurs, good reason will tell you that an oil-drain must be done earlier than usual.
If you find yourself driving regularly in these conditions, you belong to the category of “Super Severe Service”. This recommendation is for owners whose cars are constantly exposed to extreme terrain and weather conditions. In this category towing is included. When you tow a trailer in the mountains, or in hot weather change oil in the soonest time possible. For the average motorist, these situations occur rarely. The best time to make that change is when the car is at operating temperature since oil doesn’t flow as well in a cool environment. Hot oil allows for the contaminants to be drained easily. All the oil should be removed from the crankcase before it is replaced. V:12

