my daughter just called to tell me that her mpg has gone up again... last tank it was 28.12, this tank it's 29.3 mpg.

at my recommendation (ok, she's the guinne pig) I had her swap a quart of MMO for a quart of dino oil in her last oil change. she was previously getting 23~24 mpg consistently... the last 2 tanks have been the same type of driving, mostly hiway.

I read your previous post on this. I've been using MMO in my gas for a few months, but can't say that it gave an increase in mileage. I took the plunge and put about 8 - 12 oz in the oil of my Spirit and my Caravan. I just couldn't bring myself to subsituting a whole quart. I ran it in the Spirit for a few hundred miles, then changed oil. Switched from Mobil 10W-30 dino oil to Supertech 10W-30 full synthetic and again added about 12 oz. to the new oil. I haven't run enough tankfuls through either vehicle yet to say that it has helped. I did get an increase in one tankful on the Spirit, but I more than usual highway miles on that trip. I'll post back later when I get a larger range of data where I can average out the mpg. Have you noticed a consistant increase in the other vehicles that you tried it in?

I'm not sure if I mentioned it but I dumped 1 quart last weekend in the wifes truck (3.9 dak) and my other dak during the last oil changes... my dak doesnt get driven enough to track the milage but the wife is consistent in her data tracking... her last calculation was .5 mpg better than her average ( 17.74 vs 17~17.2) and that was while driving on 1/2 tank since the oil change. I asked her this morning and she said she wont need to fill up until mon/tue of next week.

In my diesel, it easily adds 1~1.5 mpg mixed with the fuel. plus the motor runs way smoother than w/o. My only thought on the fuel mix would be that maybe it's lubricating the injectors so they are not sticking.

I put some MMO in my Cavalier at the last oil change. Granted I don't run the A/C in the summer, but I got about 407 miles out of 11.7 gallons of gas. I am quite pleased.

what did you normally get?

34.8 mpg is pretty good. I wish I could get that consistantly with my Spirit. Makes me miss my old 81 VW Rabbit diesel. That would get mpg in the low 40's. Of course I couldn't pass anybody unless they were sitting at the gas station . Great running car, easy to fix, which it took a lot of fixing, but I was in college then, not married, and had a lot of extra time on my hands.

The tank holds about 12.5 gallons. If I'm really dry, I gass up with 13.2 gallons. Normally, I'll squeeze out around 385 - 391. If I gas up on the west side of St. Louis around 11pm at night, and drive to my parents in Rockford, Ill during the overnight hours, when the air temperature is very cool and there's lots of moisture, I've been able to get 432 out of a tank of gas. This is, of course, when it's just my son and myself in the car with no extra cargo.

407/11.7 vs 391/12.5... that's about 11% gain... pretty good

Eh, my record keeping is based off of my (foggy) memory. I'll track my next few fuel purchases and see what happens. I was rather surprised that I went 407 miles on that fillup. I also drive 35 miles to work, each way, every day.

hmmm I wonder what it does in a 5.3 Silverado...?