Originally Posted By: AlienBug
I use MMO in the Maxima, about 6 oz per tank, which is usually right on the 2 oz/5 gal recommendation. I have been doing this for the last month. It seems to make the engine idle smoother. Mileage hasn't changed that I can tell, but now that it's in the 20s and 30s at night, mileage hasn't decreased either, so maybe that's a plus.
In my Beetle, I've started adding TCW-3 after reading a monster thread about it on the Dodge Cummins forum. 10oz per tank (about 15 gallons) and, again, it has quieted and smoothed the engine enough that I have stopped dosing with Power Service and gone to straight TCW-3.
OT: IMO it's still a good idea to use an appropriate diesel fuel additive even if adding 2-stroke oil to the fuel. (for cetane boost, anti-gel [winter of course], fuel system cleaning, small amounts of water)