I ran accrosed this while searching the web. Yea I know....too much time on my hands sometimes. I fouond the entire site very interesting especially when they talk about the life of synthetic oils.
Might provide interesting readind for those considering synthetics.

http://neptune.spacebears.com/cars/s.../oil-life.html

 

Interesting study which took a lot of work on their part. I wish independent lab test results were available that started with new engines and different synthetic oils to see how they performed. Sometimes I think Amsoil is all hype. Amsoil is a lot higher in cost especially when you add in the transportation cost. Amsoil is not a refiner so I don't know who makes the base synthetic oil for them. I assume they add their additive package to the oil and then put their marketing spin on the product. A lot of oil blenders across the country buy base oils and then add the additive package that their commercial customers want for their engines.

I can buy a 6 pack box of Mobil 1 at Costco for $28.99 or $4.83 a quart. Local auto stores will have specials that sell synthetics for $3.99 a quart. I just bought a 5 qt. pack of Valvoline 10W-30 dino for $5.00 that I will use for our first oil change on our 2006 Honda Accord 2.4L engine at about about 2000-2500 miles. There was $2.00 rebate coupon in the box for 5 quarts of Valvoline synthetic. Local auto stores sell it for $5.39 so I may make my next oil change at around 5000 miles with the Valvoline synthetic. Product Data Sheets for Valvoline and Mobil 1 10W-30 synthetics are about identical so I will buy the lowest cost oil since I will be changing the oil by 5000 miles. Valvoline replied to my queery about which oil I should use with a statement that I should use their dino oil for our Honda!!!!

I am going to use 10W-30 oil since Honda requires that oil in Australia and probably all foreign countries since they don't have the U.S. CAFE standards imposed on the vehicles. If 5W-20 was really beneficial then wouldn't you think Honda would state 5W-20 oil since the price of fuel in those foreign countries is double or triple what we pay? And Toyota requires 10W-30 even in the U.S.!!! To me that is frustrating.