Amsoil is great.... but like all synthetics the molecules are all the same size and very smaller compared to conventional oil where the molecules very in size.
If your car leaks oil don't put synthetic in it... it will leak even more. I could not get the drain plug in my 89 Honda to stop dripping after swithced...... switched back to conventional and dripping stopped. The only way I would used Amsoil is if I started using it after the engine was broke in and I expected to keep the car for a very very long time like 15 years or more. Plus I would want the added filter system that adds 1 to 2 quarts of oil to the system. Otherwise every 3000 miles.