As I mentioned in another thread, I used MMO religiously in all my former VW Diesels, when I could get it. By putting it in the fuel, I found it quieted the clatter down so well I could hear the "vrrrroooom" of the air intake under the hood while driving. Also, a couple of days before an oil change, I would put as much as I could to top up the engine oil and drive normally, for an effective cleanout. My last VW Diesel died of terminal floor rot at 413,000 KMs, but the engine was as strong as ever.

Just found MMO again at Canadian Tire and put 8 oz. into half a tank of fuel in my 300D. After a couple of jaunts on the highway, it must have got well mixed with the fuel, and I noticed a definate quieting of the power plant, especially noticable when coasting to a stop- the 300D always seemed to emit a clatter before, which is now pretty much gone.

I swear by MMO- I don't particularly care what's in it, or what the big mystery is- all I can say is it works well, and does what it says it will do on the can.

Dave form the North Country