Why is it so important to use the correct oil when performing an oil change in your car or truck’s engine? Today’s vehicles have requirements for low emissions, high fuel mileage, and customers want high horsepower.

To meet these requirements modern engines are much more complicated, with internal systems such as variable valve timing. There are actuators inside the engine that are operated by engine oil based on oil pressure. If the correct grade or viscosity of the oil is not used problems with how the engine performs can arise. This could cause a check engine light to come on. We have plenty of examples of fixing a check engine light. Engine drivability problems can be solved by using the correct oil during an oil change.

What is the difference between high mileage oil and regular oil?

There have always been two different positions when it comes to this topic. Many believe that you should switch to high mileage when your vehicle reaches 75k miles. Another opinion is that you should switch if your vehicle is getting older and your engine is showing signs of loosening. If you frequently notice oil leaks on your older vehicle, you should start using high mileage oil. Engine noises such as rattling can benefit from a denser high mileage oil as well.

If you arent experiencing any of these issues there is no need to change your engine oil. Typically high mileage engine oils are not licensed and using them could affect your warranty

What makes high-mileage oil different?

High mileage oil is designed to care for older engines. The ingredients in high mileage oil care for the seals, have antioxidants, detergents, and wear and friction additives. High mileage oils contain viscosity modifiers that are durable and won’t diminish over time. This causes the oil to stay thicker for longer periods of time, helping protect your engine parts.

Over the course of the life of a vehicle, everything begins to loosen. As the engine ages, your gaskets, seals, and non-metal parts begin to wear. High mileage oils are designed with additives that increase flexibility and restore shape to these parts. This can help with oil leaks in the long run. High mileage oils are designed for engines that are beyond the warranty mileage.

What’s the downside of high mileage oil?

Some of the thicker oils, such as 10W-30 full synthetic and 5W-20 full synthetic can make your vehicle harder to start. This is especially true in colder temperatures. They can also reduce the circulation around the engine and increase your overall oil pressure. This will result in more pressure trying to push the motor oil between seals and gaskets.

What can happen if the correct oil isn’t used

If the correct oil is not used the vehicle warranty could be affected. For these reasons, at G&G Auto Repair we always look up the manufacturer’s required oil specification for every vehicle when we change the oil, and we only use an oil that we verify meets that specification. We use oil from a variety of sources. Even popular brands of synthetic oil don’t meet the specifications of every manufacturer. Whether you have your oil changed here or at another repair facility, it’s important that the correct oil is used in your vehicle’s engine.