Amsoil is the best. Check out their website they have a lot of usefull info.

I run Mobil 1 mainly because of availibility. I also run 10,000 drain intervals. Once you use synthetic you will never go back. Keeps the engine much cleaner than dyno juice. I have proof of this (taken apart a few engines, some using syntheticand some having had regular oil changes with dyno juice.

When I first bought my Toy, I ran dyno juice (10W40 Castrol) but started having a lot of engine noise at 2,500 miles. Now I run 10W30 Mobil 1. I get better oil pressure when the engine is hot (running for several hours in the sand dunes) and in 10,000 miles I do not have any increas in engine noise.

As for the trans, redline all the way.

Bottom line for me. Dyno juice is fine and will not shorten you engine life. You just have to change is more often. Synthetic stands up to heat much better and you can get a lot more life out of it.

One more oil related fact. Conventional oil is not as conventional as people like to think. Oil comes out of the ground with only 1 viscosity. For example 5 weight, 20 weight etc. It does not come out 10w30. They may 10w30 by starting out with 10 weight oil and then adding synthetic viscosity enhansers that at temperature thicken up the oil to act like a 30 weight. The base oil (10 weight in this case) will never break down. Over time in your engine the viscosity enhansors break down and you have straight 10 weight oil in your engine. Synthetic oil is built from the ground up as a multi-weight and will not break down.