.....I don't know the recommended interval but plan on going at least 10K km. with it in my Toyota Tacoma V6, assuming the stuff isn't getting real dirty.
Your toyota seems to be running pretty cleanly ....I'd feel comfortable going at least 7500 miles on the Delvac 1 without testing it. I expect it to hold up about like the Mobil 1, 0w-40 in a gas engine ....