Bringing this one back to the top with a new question. This fall I will begin driving my '91 Toyota pickup 500 miles per week. Up to now I've changed the oil every three to four months as I only put about 4,000 miles per year on the truck.
Given that I will now be putting 20,000 miles per year on the truck and a 3,000 change schedule would mean oil changes every 1-1/2 months, I'd like to extend my oil change interval.
I've used dino oil exclusively in this truck since I bought it with 28,000 miles; current miles are 97,000. Oil consumption is nil and a recent compression check revealed very little decrease from new specifications. I just completed my first application of Auto-Rx and am running a 1,500 mile interval on Mobil Drive Clean 10W-30 prior to a second Auto-Rx application.
Any suggestions as to a good choice in oil going forward? It does get very cold up here in the winter and so I am considering a dino/PAO blend. Given the age and miles on the truck, would I have a problem running a dino/PAO blend? Does a full synthetic make sense for this old pickup given that I will be increasing miles driven by a factor of five on an annual basis?
Thanks for any and all comments and suggestions.