I decided to try the Marvel Mystery Oil again, in this case in our 2007 Honda Accord. Although I got 38.5 MPG in out 2006 Accord, I wanted to see if it wasn't a fluke and tried it in the car I drive most often and under the same conditions: long trips and about 20% A/C use. The 2007 Accord gets 33-36.5 MPG in this kind of use. The best ever was 36.5 MPG.
As always, I drove using techniques I outlined in my post on maximizing fuel economy. The only difference was I added about 4 oz MMO to fuel.
I added 4 oz of the Marvel Mystery Oil (MMO) to the tank and filled it up with regular 87-octane gas. This time I drove 526 miles before refueling and refueled with 13.58 gallons of gas, averaging 38.7 MPG. Again, I never was able to get more than 36.5 MPG in this same car before. And this MMO test included a couple of short trips and about 30% of time I also used A/C. Without those, I probably would be able to get to 40 MPG. This is an impressive 2-4 MPG improvement - about 5-10%. And I expect MMO to keep the fuel system clean, even when using semi-questionable gas. Perhaps I will give MMO another try in my 2004 Infniti G35. The previous attempts did not achieve much.
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