For a 0.3 jump in HTHS? I'm comparing the Amsoil ACD to Redline 10w-30. Amsoil offers very slightly better cold flow (I run it year round) and a lower 100cSt viscosity along with a nice 3.5 HTHS. Redline has the higher HTHS and slightly higher viscosity all around. Would anyone switch for the extra HTHS in two otherwise similar oils? Just wondering how much weight you guys would put in the difference in HTHS keeping in mind I plan on driving it until the wheels fall off. Chances are I'm not going to do this because at this point I can honestly say the car has had the same oil for 90% of it's life and I want to keep it that way. This way when it goes off to the junkyard I can tear it down and post pics of what an engine that spent it's life on ACD looks like. I'm not going to try their 5w-30 with an identical HTHS because I believe it has VIIs and that's part of my experiment, to run the engine's entire life on a VII-less oil to compare piston ring land deposits.