2000 Honda CRV: If I stick to 4oz per 10 gallons of gas - then no MPG gain, but engine does seem to be smoother while I work it through the gears. If I do heavier dosage (like a pint per tank of gas) then it still feels smooth, but a bit more sluggish. In a small Honda engine every horsepower gained or lost is VERY noticeable.
2006 Toyota Camry V6: Added anywhere between 4oz per 10 gallons all the way to a full bottle to tank of gas. Never noticed any difference as 1MZ is already a silky smooth engine, no MPG gains.
2010 Volvo XC70: Haven't tried MMO in it yet. Will try once I fix the alternator gear...
Some of my previous cars gained MPG though, when the recommended dosage was followed. Some of these cars:
- 2005 Nissan Altima 2.5L,
- 2001 Honda Civic 1.7L
- 2002 Honda Civic 1.7L
- 2001 Lexus IS300 3.0L
- 2004 Lexus IS300 3.0L
- 2009 Toyota Tacoma 2.7L
- 2009 Scion xB 2.4L
- 2003 Pontiac Vibe 1.8L
- 2006 Pontiac Vibe AWD 1.8L
- 2000 Lexus GS300 3.0L
- 2006 Toyota Highlander Hybrid 3.3L AWD
- 2006 Volvo XC90 2.5T AWD
- 2013 Volkswagen Tiguan 2.0T AWD
- 1995 Chevrolet Tahoe 5.7L 4x4 (On this one I once added a gallon of MMO to 30 gallons of fuel just for S&G. That was a disaster.)
There were also a few cars that lost MPG no matter the dosage. But if dosage was followed - every car replied in smoother flow through RPMs, and some (not all) even had better throttle response.