Car and engine manufacturers give recommended oil change intervals of around or between 2,000 to 7500 miles (corresponding to 3,200 to 12,000 km) between oil changes depending upon operating conditions. There are so many variables such as engine load, short trips, speed, prolonged idling and dust that an exact recommendation that fits all vehicles, their climates and environments and driving patterns is virtually impossible.
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 states that motor oil must be changed at “regular intervals” based on the recommendation of car manufacturers. Upon checking the manual, proceed to the page where “severe service” is found. It will have two bases for changing oil, time and distance traveled. Let’s take the examples three months and 3,000 miles as examples. If you’ve already traveled more than 3,000 miles in the 2nd month, an oil drain must be done. Always follow the one that applies first in your situation. Remove 10% from the recommended mileage during summer and 20% in winter. For example, in summertime a scheduled oil change should be in order every 2,700 miles traveled. These suggested periods will ensure car owners maximum protection from oil contamination and additive depletion.
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
