to Amsoil. I have been running Redline 10w40 for about 8k miles. I also run the K&N oil filter, I changed the filter at 4k miles and added a quart of oil. I could tell a big difference in how the car ran when I switched from Mobil 1 to Redline about 8k miles ago. I love the redline! But I have heard nothing but good things about AMSOIL so I think it is time to change over. Which AMSOIL should I run? I was going to buy SAE 10W-40 Synthetic High Performance Motor Oil...I figured that is what is comparable to the Redline 10w40...am I right? I have 80k miles on my LS1 with full exhaust, and nitrous just incase you guys were wondering.