Whether you have questions pertaining to motor oil performance, synthetic oils or how to recycle your used oil, you can get the answers you’re looking for below. First, narrow the options down by choosing the closest-related category to your question.

Oil Types, Weights & Viscosity FAQ

Is it ok to switch motor oil weights, for example, from a 5W-20 to a 10W-30?

It depends. Some vehicle manufacturers provide a range of recommended motor oil viscosity grades based on the outside temperature in which the car is driven. Other manufacturers recommend the use of only one motor oil viscosity grade. For best engine performance, always follow the manufacturer's recommendations found in your vehicle’s owner’s manual.

Is it ok to use 5W-30 in a car if the owner's manual calls for 5W-20?

Valvoline does not recommend doing this. Using a heavier grade than recommended may cause decrease in fuel economy, higher engine loads and eventually shortened engine life. Using a lighter grade than recommended may result in excessive mechanical wear and reduced engine life. For maximum engine performance, follow the recommended motor oil viscosity and maintenance schedule provided in your vehicle's owner's manual.

What does the "w" in a grade of motor oil stand for?

The "w" in motor oil stands for winter. The first number in the oil classification refers to a cold weather viscosity. The lower this number is, the less viscous your oil will be at low temperatures. For example, a 5W- motor oil will flow better at lower temperatures than a 15W- motor oil. The higher number, following the “w” refers to hot weather viscosity, or how fluid your oil is at hot temperatures. The higher the number, the thicker the oil at a specified temperature.

Is thicker oil better?

In some circumstances, thicker oil can be used to compensate for increased bearing clearances (gaps between bearing and rotating shaft) that have developed over the years. A large change in bearing clearances can result in poorer lubrication. For best performance always follow the recommendations for motor oil viscosity in your vehicle's owner's manual.

When does it make sense to use straight weight oil (SAE30) versus a multigrade oil (5W-30)?

Straight weight oil is never recommended for use in a system that requires a multi-viscosity oil. Straight weight oils are generally recommended for smaller engines or older vehicles that were made before multi-viscosity oils were produced.

Is switching types of motor oil (conventional, synthetic, etc.) harmful to my vehicle's engine?

Conventional, synthetic blend, synthetic and high mileage motor oils are compatible and will not harm your vehicle's engine. For maximum engine performance, follow the motor oil type recommendation provided in your vehicle’s owner’s manual.

Is it true that older cars must only use conventional oil?

No.

Do I have to wait until my car reaches 75,000 miles before I can use MaxLife?

Valvoline MaxLife motor oil is designed for high mileage vehicles of 75,000 miles or more. However, it is perfectly acceptable to use the high mileage motor oil in new or used vehicles with less than 75,000 miles.

Has MaxLife always been a synthetic blend motor oil?

MaxLife Synthetic Blend motor oil is actually the same product as regular MaxLife. MaxLife has always been a synthetic blend oil; we just now label the product that way. As long as you have used MaxLife, you have used synthetic blended oil.

How do Valvoline full synthetic motor oils compare to Mobil 1 and Amsoil?

Valvoline's full synthetic motor oils meet and exceed the same specifications as these two products.

Valvoline full synthetic motor oils are high performing, high-quality oils formulated with full synthetic base oils and top tier additives to provide an increased level of performance. All of Valvoline's full synthetic motor oils are API licensed to ensure quality for North American vehicle application. We have specially designed Valvoline SynPower 5w40 for application in high performance European or diesel passenger cars and this oil carries the specific OEM approvals such as Mercedes Benz, Volkswagen, Porsche and BMW. Our North American SynPower 5w20, 5w30 and 10w30 exceed ILSAC GF-5 requirements and carry the API starburst on the front label. Valvoline full synthetic motor oils are designed with extra levels of detergent and antioxidant to provide outstanding deposit and heat protection.