Q. I have read the NOACK tests and the "3,000 miles oil change" fallacy. I have been using the AMSOIL Signature Series 0W-30 synthetic oil, AMSOIL SDF-29 filter and AMSOIL Air Filter. I have been following directions cleaning and re-using the air filter on a once-a-year basis and changing the oil filter twice a year. I leave the oil in for the full year. That amounts to between 5,000 and 6,500 in the one year period.

I have recently purchased a brand new 2001 Pontiac Grand Am with the 3.4L engine. I also have purchased the GM Factory extended 6/60 warranty. I received the warranty book and read it. Much to my surprise I find the following reference under "Your Responsibilities" in the warranty book:

"YOU must properly maintain the covered VEHICLE which includes, but is not limited to, changing the engine oil at a minimum of every 3,000 miles or as recommended by the vehicle manufacturer. If requested, proof of required service, including receipts and work orders showing date and mileage of the VEHICLE at the time of service must be presented to US in the event of a FAILURE or CLAIM."

Because of this I fear switching to the AMSOIL 0W-30 synthetic oil and oil filter and leaving it in the engine for the full year or 35,000 miles thus risking voiding the factory warranty. Is there anything you can do to contact GM and convince them of the fallacy of the 3,000 mile oil change and convince them to use and recommend AMSOIL synthetic oil in their cars? They are convinced enough to use Havoline "extended" drain interval antifreeze, why won't they see the advantages of extended drain intervals using AMSOIL synthetic 0W-30 oil?

A. The language in the extended warranty protection plan was written by an insurance company, and is definitely intended to intimidate you into changing your oil every 3,000 miles. They are doing everything they can to try to limit their liability for claims and create wiggle room. What's new!

All of the vehicle OEMs in the U.S. have agreed that a new car warranty cannot be denied because a customer was using any brand of motor oil at any length drain interval unless an engine failure was directly attributable to the oil or drain interval. For example, if your radio, power steering unit, air conditioner, etc., broke down, they could not void the warranty that covers those items because you were changing your engine oil at 6,500 miles or one year. If it is not an oil related failure, they cannot void the warranty. The law supports this position.

If your engine failed, and the manufacturer denied your warranty for repair due to your using extended drain intervals, then you would submit your claim to the AMSOIL Technical Services Department for handling. (See the AMSOIL Guarantee Limited Warranty.) Our staff will analyze the oil, and if we are able to provide documentation that proves the source of the problem was other than the oil, and that in turn allows your claim to be processed under the original warranty, then we will. If no proof can be assembled regarding the source of the problem, our insurance adjustor will be dispatched to resolve the claim. A warranty claim being denied because of the use of extended drain intervals is an extremely rare occurrence. That's because motor oils do not cause engine failures dirt, glycol and other mechanical problems do.

Ironically, in Europe the auto manufacturers recommended drain intervals are from 12,000-18,000 miles using petroleum products, and are moving even higher. In the U.S., it has been published that auto manufacturers are also going to be moving toward extended drain intervals of up to 15,000 miles in the not too distant future. GM is currently moving toward a system that tells you when to change your oil based upon a computer program that evaluates your driving habits. Some other car companies are planning on having an on-board oil analyzer to tell you when to change your oil. This will allow for shorter drains for poorer quality oils and longer drains for higher quality oils, where G.M.s system will not distinguish between the two. As these changes develop, so will the language in owners manuals as well as extended warranty policies.

You've used our products successfully for 7 years, and are following all of our recommendations for air filter cleaning and oil filter changing. You have our warranty coverage to fall back on in the unlikely event of an engine failure that is not covered by your vehicle warranty. I hope you will not be intimidated by the language in your extended warranty policy and will continue to use the highest quality and best performing products that you can, AMSOIL motor oil.