A long, boring trip to Los Angeles and back got me thinking about OIL and other things. Then stopping at a Pilot Truck Stop on I8, I bought 18 Gallons of Gas, 2 Donuts and 3 Gallons of Mobil Delvac 1 5W40. A few more miles and I'm swithcing to the Delvac 1 5W40 year round in both Toyota V6 trucks. They're at 15-20K miles and I've only used Mobil 1 5W30 with good results since new. I want to run 10K OCI with an Amsoil filter change at 5K and 10K intervals. TIA for any feedback. Comments? Concerns? Critisisms?