I think Dexcool could work in place of Japanese extended life coolant. I wouldn't feel comfortable using it in place of LL on older models. The only potential problem would be that Dexcool can gum up with air and Japanese cars generally don't have pressurised reserviors. Some people get away with it, even GM got away with it most of the time, but not always. I've seen the Dexclone gum up quick.