Just want to know: Does anybody out there use Marvels Mystery Oil and what have your experiences with it been?

The only thing I know Vac, is they have been around selling products for many years for cars and airplanes.

Talaniman: I just want a sanity check for my own experience to see if I just being delusional or what...albeit even though it is an early trial, the results are startling, to say the least: My vehicle has been averaging 29.5 MPG for a time period of the last 90 days. On Sunday, I filled the gas tank and added 8 ounces of Marvels Mystery Oil into the gas tank....then proceeded to drive 330 miles....this vehicle has a fuel monitoring system that displays instantaneous MPG and average MPG: I ended up with an Average MPG of 31.5 for that trip! And I am continuing to average that since then. That is impressive, to me.

Next, I am about to try it in the engine oil and see what that produces.

I do know, from experience, that it is an excellent firearms cleaner that provides a long lasting rust inhibitor to the blued and unblued surfaces and really helps smooth out actions.....Just never used it for its "intended" purposes...until now!

I've heard really great things about this, however, maybe some controls in your experiments would do well.

Run a tank without it, see if the effects last.

Maybe try it on another vehicle and/or driver to see if there are similar results.

I have always run various cleaners through my oil and gas periodically (every 10k miles or so) for maintaining the engine. My PT had a head job, the insides were still pristine, 180k at the time, barely any wearing on the cylinder walls, clean valves and pistons, no major deposits anywhere in the upper half, at 240k now with original injectors and heads.

The cleaning action of Marvel might give you a boost back to newer condition, but likely isn't necessary in every tank.

InfoJunkie4Life: like your advice! Yes, this is the 1st vehicle I ever had with the MPG counter on it.....who needs a cell phone to distract you from driving when you have this! But ALL of my vehicles, except this one are high mileage: 130 K, 265 K, and 290 K.....and still going strong. I have been a big LUCAS supporter, especially their Transmission treatments and I have tried Sea Foam but don't like it.

Lucas stops slips....even got rid of the lurching when, in a desperate moment, I dumped dextron in my chrysler. Ran 100k miles more without flushing. I'll run ATF for an oil change through a dirty engine to clean it out and puff up the seals.

I do think an agressive fuel system cleaner/lubricant like your mystery oil is an effective way to preserve the top half.

InfoJunkie4Life: We may be related! I did the very same thing with slipping band on a '99 Ford Explorer: at around 135 K miles, it started to slip and, so, I gave it two consecutive doses of Lucas Transmission Treatment over a year or so period....never felt a slip again, and that was about 155 K miles ago!

So, over the years, in my older, high mileage vehicles, I have put Marvels Mystery Oil in only the oil but hadn't yet put it into the oiler of my newest, secondhand vehicle...I will do that next....Putting it into the gas is something new for me, never did that on my older vehicles...have used Lucas Gas Treatment in them, though....But, if your think about the lack of lubrication that the tops of the cylinders see, the idea of putting MMO into the gas is really a good idea because it continuously lubes the top! Were only talking 4 ounces MMO/10 gallon gas for continuous treatment.

Now, I did learn a trick that I have put to great use in all my old vehicles: Start the vehicle, put someone behind the wheel, get the RPMs up on the motor, pull the vacuum line off of the break connection and stick it into a container of MMO, bringing the RPMs up as you do this (you don't want to stall the engine): The result is complete carbon removal out of the head.....you should see the crap that comes out of the tailpipe: BLACK! Had a Cadillac Deville where the lifters were starting to stick: Did the little vacuum line MMO pull: Click completely gone!