Frequently Asked Questions

Is it really necessary to change my vehicle’s oil every three months or 3,000 miles?

If most of your driving is around town with lots of stop and start wear and tear the 3,000-mile interval is the best preventative maintenance. If you’re in doubt, remember that it’s cheaper and easier to change your vehicle’s oil than replace the engine. If you drive long distances at highway speeds, it may not be essential to change your oil every 3,000 miles.

What’s the difference between "high-mileage" oil and regular oil?

"High mileage" oil does differ in formulation from traditional conventional motor oil. It utilizes special base oils that provide superior protection against oil "burn off" in higher mileage engines. It also contains specially formulated seal conditioners and additives that reduce deposit formations, which can lead to compression loss. If your car is five or more years old and has more than 75,000 miles on it, high mileage oil would be a good thing to consider.

What is considered a high-mileage vehicle?

Generally, any vehicle with over 75,000 miles is considered high-mileage.

"I was always told to change my oil every 3,000 miles if I wanted to keep my car running well. How is it possible to drive 7,500 miles without an oil change using AMSOIL, and will extending my oil change interval void my warranty?"

AMSOIL Synthetic Motor Oil, in gas aspirated engines, is RECOMMENDED to run for 7,500 miles or six months (5W-30, 10W-30, 10W-40) in a mechanically sound engine. Amsoil coined the phrase "extended drain interval" and it's been validated by almost 30 years of industry testing and by hundreds of thousands of motorists and millions of over-the-road miles. Based on their results, 7,500 miles is a conservative estimate. Other Amsoil engine oils, 15W40 as an example, carry a recommended change of two to 3 times the normal manufacturer's recommended change interval.

AMSOIL Synthetic Motor Oil performs so well for so long because it doesn't break down in intense heat as conventional petroleum oils do. It doesn't form performance-robbing deposits, and it doesn't volatize, which can adversely affect lubricant performance by altering viscosity and increasing oil consumption.

Note also that extending drain intervals, like using AMSOIL Synthetic Motor Oil in general, does not affect new car warranties. In fact, according to a GM representative, "Warranty applicability is contingent upon the cause of failure and generally covers defects in material and workmanship only." In other words, the only situation in which warranty coverage would change is the case of lubricant-related failure (in which case the AMSOIL Limited Warranty protects the consumer).

Why are AMSOIL synthetic motor oils good for extended drain intervals?

It's all in the formulation. Because AMSOIL is made with synthetic basestocks, it resists thermal and oxidative breakdown, which suits it for extended drain use. AMSOIL pairs top-quality long-life synthetic basestocks with top-quality long-life additives. The fact is, other oil companies don't use the quality additives AMSOIL uses because it simply doesn't pay to pair long-life additives with short-lived conventional basestocks. Carefully controlled demonstrations conducted jointly between AMSOIL and various car fleets have proven the safety and effectiveness of the 7,500 mile AMSOIL drain interval. In fact, many entities with which AMSOIL has conducted demonstrations have used the oil for significantly longer drain intervals and still been rewarded with lower rates of engine wear than they were with conventional lubricants and conventional oil drain intervals.

Why Change Your Motor Oil?

Dust, metallic shavings and even antifreeze contaminate motor oil. As contaminants are whipped into the oil, sludge is formed. This sludge will stick to parts of the engine causing the engine to perform less efficiently. Eventually, this sludge can cause engine failure. Why Change Your Oil Filter? The oil filter's job is to remove oil contaminants. It sifts out the solid particles while allowing the oil to flow unrestricted through the engine. When the oil filter becomes "full" or "clogged", the oil and contaminants will flow around the filter. When bypassing occurs, contaminants head straight for the engine where they can eventually cause permanent engine damage. How Can You Avoid Warranty Problems? Keeping your car maintained during the first year is an important part of protecting your warranty. Your owner’s manual tells you what is required. Be sure to always save your maintenance receipts. Under the Magnuson-Moss Warranty Act, 15 USC SS2301-2312 (1982), and general principles of the Federal Trade Commission Act, a vehicle manufacturer may not require the use of any brand of filter (or any other article) unless the manufacturer provides the item free of charge under the terms of the warranty. If a consumer is told that any other filter except the original equipment filter will void the vehicle warranty, the customer should request that the OE filter be supplied at no charge. If the dealer or manufacture charges the consumer for the filter, they are in violation of the Magnuson-Moss Warranty Act. By providing this information to consumers, the Filter Manufactures Council can help combat the erroneous claim that a brand of replacement filter other than original equipment will "void the warranty".