There seem it be a large enough number of people on here and other sites using TCW3 that have before and after numbers for fuel economy showing that it helped, that I'm currently trying it. They could all be lying about it to prove their point, I don't know, but enough people I figured it was worth trying at 1:640 ratio. My driving habits are not steady enough for me to get any conclusive before and after results.The fuel system does not need to be lubricated.