Here we go again. I have Amsoil front to back, including grease, oil filter, and air filters. Been using their products for over 26 years with success. They were the first API certified synthetic on the market in 1972. Mobil One came out 3 or 4 yrs. later. I have no problem with Mobil One. I just happen to think it is purely marketing which put their product in the Viper. Do a search on this subject and a little more DD. Apex Motorsports, a reputable tuner for these cars who advertises on this board, uses Amsoil products.
There are differing opinions here on whether synthetics are even the way to go. Some use mineral or synthetic diesel oil for reasons you'll find if you do a search.
Steve