In 1972 Amsoil entered the synthetic motor oil business with introducing the first fully synthetic 10w-40 motor oil to meet SAE standards. Adding to the first category is the 25,000-mile oil change interval.Fast forward to today and Amsoil is the leader in the synthetic motor oil industry. Amsoil has a synthetic engine oil for any application and any engine be it large or small commercial or the family car.Amsoil has three tiers of automobile engine oils to fit your level of comfort with extended oil changes.1. Is Amsoil's best oil. Amsoil Signature Series synthetic motor oil. Recommended change intervals are 25,000 miles nonsevere service and 15,000 severe service. Most customers will only change their oil at an interval of no more than twice annually.2. Amsoil XL is Middle of the road oil with a 10,000-mile oil change interval no matter what type of driving you do. This is the perfect synthetic motor oil for those that have a set schedule for longer maintenance schedule.3. Amsoil OE is a synthetic motor oil for those that chose to follow the manufactures suggested oil change interval, whatever that may be. Many new vehicles have suggested change intervals from 5,000 to 10,000 miles.Amsoil motor oils in all three grades come in all popular weights mandated manufacturers These include but are not limited to 5w-30, 0w-20, 5w-50 and more!visit our web page now to find out which Amsoil motor oil is right for your car. http://www.SyntheticMotorOils.Direct