Thank you, I learned a lot in that paragraph and I think you nailed it for me. I do the additives you suggested, thanks, I feel better after reading this.
A year ago I bought a 2011 Avalon, it drove and still drives like a new car with 80 thousand miles on odometer. 2 wks later I was on the highway and pushed the peddle to the carpet at 40 mph, the motor erupted with the power of a volcano eruption!! I thought the front end came off the ground...