Because modern vehicles are stronger, cleaner, and more durable than those of yesteryear, most automotive experts believe that changing motor oil every 3,000 miles is overkill. Depending on the make and model, some cars and trucks can safely travel upwards of 5,000 miles between changes. Car owners' manuals are starting to reflect this growing consensus with longer oil change intervals. There are, however, exceptions that may affect manufacturer's recommendations. Here are five of them.
1. Hard Driving
Almost as important as the actual mileage is the type of driving an owner does regularly. If he uses the car or truck to tow a trailer or pull heavy loads, that will invariably put more stress on the engine, causing it to operate at higher temperatures. Because extreme heat destroys the lubricating ability of oil through excessive oxidation, it will need to be switched out more often. In addition to towing heavy loads, driving on bumpy, unpaved road surfaces often puts more stress on the motor, causing it to run hotter than it normally would.
2. Environment
For obvious reasons, higher engine temps are more likely when it's warm outside. If you reside in a region of the country that experiences year-round warm weather, oil change intervals should be shortened. This is true whether you engage in hard driving or not. It is also important to note that environments that are very dusty and / or polluted can increase the risk of fluid contamination. In other words, there's a greater chance your motor oil will get dirty and need to be replaced. For those living in dusty desert towns or in polluted cities, it's often a good idea to visit the service station every 3,000 miles.
3. Short Commutes
It might surprise you to learn that a short daily commute may actually be harder on your engine than a slightly longer one. The reason? Because short trips do not give your motor the time it needs to reach an optimal operating temperature, lubricating fluids may be degraded. What actually happens is that excess fuel spills into the crankcase, diluting motor oil. This excess fuel is needed because cold engines require more gas than warm or hot ones. Spilt fuel can also break down the lubricating chemicals in the viscous liquid.
4. High Performance
If you have a turbo-charged engine, it will run hotter, on average, than a regular one. Even if you use synthetic liquid blends, it's probably a good idea to shorten oil change intervals with these vehicles. This is particularly true if you live in a warm environment, drive hard, or tend to travel over the speed limit for protracted periods of time.
5. Engine Age
With all other things being equal, the more miles you have on your odometer, the dirtier your motor will be. As such, the liquid that is used to lubricate moving metal components will get dirtier faster. Because dirty motor oil does not have the lubricating ability of clean fluid, it is more likely to cause friction that can do damage to vital engine parts. For this reason, change intervals should be shorter for high-mileage vehicles.
All drivers should consider these five factors before calculating a safe, reliable service schedule for their vehicle.