98ramtough

After reading some of the reports of 2 cycle oil added to fuel increasing mileage and making the engine run smoother I tried it today. I only have 150 miles on the tank, but my computer shows mileage very accurate. Before I was getting 18.5 according to the computer, and 18.3 hand calculated. After adding 6oz of valvaline 2 cycle outboard oil to the tank of fuel I am getting 21mpg. I have an 07 5.9 with 3700 miles on it. I drove the same on all tanks, driving about 65mph on the highway, a little stop and go in town. I am suprised, but the truck is quieter at idle, and I am getting very good mileage. Hope its not a fluke and continues. I will be adding a little 2 cycle at every fillup if this continues!

danc46

I don't believe the two stroke oil is giving you better mileage. I just tried two stroke oil in my 06 Cummins coming back from New Mexico. Interstate driving at around 2000 rpm netted me less MPG (almost a full 1 MPG) than a 50/50 mixture of Power Service and Marvel Mystery Oil on the same road getting to New Mexico.
I have just over 10, 000 miles on my truck.
Your engine is just getting more efficient as it wears in.

cad14man

I have been running 32 oz per tank which comes out to about 100:1 Ratio. I have noticed about 2 mpg and engine runs smoother too. I run 1 gallon of 2 cycle then run one or two tanks of power service to make sure the injectors dont get gummed up.

DBLR

Sticking/gummed up injector (again) at start up is what I got after only 175 mile drive with only 16 oz of 2 cycle oil in a tank of fuel. I'll just stick with Lucas from now on and not have to worry about injector problems.

98ramtough

Well it looks like it was just a coincidence for me. I hand calculated the mileage again and it was great, 20.8mpg, with no oil in the tank. I will probably quit using it and start adding another additive every other tank. It did quiet it down a bit at idle, but the mileage must have just been from the truck starting to breakin. It has 5k miles now, and the last 4k have been towing miles.

HotRodK

I am running Lucas upper cylinder lubricant. It is $8.95 for 100 gallons of treatment and Im happy with that.
I also think its funny hearing about getting better fuel mileage when you just increased your cost per gallon by adding the additives. Your not saving money that way.

Deesil

I agree with useing whatever add-mixture to try and better protect the fuel system or engine. Use whatever you feel comfortable with to do so. However, don't do it for mileage, that's plain silly. There is nothing out there that is going to improve mileage for any sustainable and discernable period when you factor in the cost of the product in the first place.