2 stroke oil in Diesel?

tomd999 · Apr 11, 2011

Hi,

About a year ago I read numerious postings on Dodge/Cummins Diesel forums that people had found mixing in Wally World 2 stroke oil at about a 200-1 ratio had noticed a slight increase in the number of miles per tank and a bit more "seat of the pants" torque and power.

I figured it couldn't hurt my 300+K Dodge so I gave it a try. Since new, this truck has gotten 450 miles per tank when I drive it reasonable and not loaded to the max and the first tank with the 2 stroke mix, it got 475 miles, the 2ed tank it went to 480 and the third it topped 500 miles per tank. It's been between 480-500 miles per tank for the last year as long as I mix it at about 175-1 ratio. If I stop using the mix, it will gradually fall back to it's historical miles per tank of 450.

At the same time the truck was getting more miles per tank, I noticed it felt like it has quicker spoolup and thus a little more grunt down low and it has more of the Diesel rattle like it had when the sulfur was in the fuel.

If I mix it richer than 150-1, I lose all the benifits and it smokes going down the road like a good little 2 stroke...

It's not all upside however, the mix does make it a little rougher when it's cold.

OK, now my question, Why does adding 2 stroke oil get me added miles per tank and a little extra power??

Tom

Transit · Apr 11, 2011

One thing for sure is that it is not the added BTUs. Maybe the effect of top lubing the cylinders and rings?

mrutkaus · Apr 12, 2011

Have you thought of a blind test where you allow a friend in the garage alone with the truck for 15 minutes with you far away, and they either add the proper amount of oil or not?

I remember reading where people using gas saving devices would drive differently when they knew they had them!

Mike

Transit · Apr 12, 2011

Good point. Only a dino test could tell if there is any substance to mixing oil into the fuel. Come to think of it, Marvel Mystery oil did the same thing. So dose Ken's ranch dressing with extra garlic. Chili sauce?

schoolsout · Apr 12, 2011

The oil adds lubricity to the ULSD and is the reason it is used (what I've heard). Added mpg is interesting, though.

jonyyuma · Apr 12, 2011

I used Marvel mystery oil for years believing it lubed the fuel inj pump. I never did have a inj pump failure.I had tried the 2 stroke oil, but only one tank, did not notice much difference, but that oil has anti-scuff in it, possible it changes the friction in the cylinders? Air cooled and water cooled oil for a boat motor used to be different formulas?

tholder85 · Apr 12, 2011

I put a pint of the wally world 2 cycle oil in my Ford F250 6.0 about every other fill-up, which is not too often these days with the price of fuel:smiley_aafz:, I try to leave it parked unless I need it!

Mace Canute · Apr 12, 2011

As a diesel fuel lubricant additive, MMM sucks the big one. 2 cycle oil does work but it's not the best. Check it out here..http://rivrdog.typepad.com/files/copy-of-diesel-fuel-additive-version-3.pdf

The BTU value of 2 cycle oil is 138,000 BTU/gallon and diesel fuel can vary from 126,000 to 133,000 BTU/gallon. For the small percentage that you add to a tank (200:1 ratio), the extra energy in it isn't going to make a noticeable improvement in mileage...other factors will easily outweigh it.

Transit · Apr 12, 2011

This all sparked my interest so I poked around some. Upper cylinder liberation may have made sense in the early days of engines. Now with better designs, materials and oils there is no advantage. As a mater of fact, the extra hydrocarbons may not be doing your cat converter any good by working it harder. So go easy on the additives to lube the injector pump, more is not always better.

Jay4200 · Apr 12, 2011

tomd999 said:
OK, now my question, Why does adding 2 stroke oil get me added miles per tank and a little extra power??

Rings seal better. I used to mix a 4oz bottle of cheapo stinkwheels oil into every tank when I had an old Toyota Corolla (~300:1). The car appeared to get better mileage with it, and it seemed to run better and have more poop, but I never did a qualitative experiment.

JayC

jonyyuma · Apr 12, 2011

Transit said:
This all sparked my interest so I poked around some. Upper cylinder liberation may have made sense in the early days of engines. Now with better designs, materials and oils there is no advantage. As a mater of fact, the extra hydrocarbons may not be doing your cat converter any good by working it harder. So go easy on the additives to lube the injector pump, more is not always better.

If you are talking about a gasoline engine, hence converters, the oxygen sensors can be knocked out by just a little oil fouling. There could be 4 of them lurking under the hood and about $300.00 plus for replacements. So no I don't add it to my gasoline.

boomer1025 · Apr 12, 2011

Two cycle oil in the fuel slows down the burn time of the fuel in the cylinder. Poorman's high test fuel.
I'd use a two cycle oil that was rated for use with converters, if I was mixing it.

Transit · Apr 12, 2011

Jay4200 said:
Rings seal better. I used to mix a 4oz bottle of cheapo stinkwheels oil into every tank when I had an old Toyota Corolla (~300:1). The car appeared to get better mileage with it, and it seemed to run better and have more poop, but I never did a qualitative experiment.

JayC

i would think that it would take a lot more oil than a 300:1 mix could provide to improve the ring seal. Time for a dino test.

Gale Hawkins · Apr 12, 2011

I use WM TC3W spec outboard oil in the tractors at about 128:1 just cut injector pump chatter. I use it at about 500:1 in gas to lube in-tank fuel pumps that I really do not want to replace.

If it gives more miles/hours to the gallon I did not pick up on that but then that is not a concern that I have. I buy it as lube product only.

Skyco · Apr 12, 2011

boomer1025 said:
Two cycle oil in the fuel slows down the burn time of the fuel in the cylinder. Poorman's high test fuel.

2 cycle oil lowers the octane of gasoline...it speeds up the burn time.

nwltruck · Apr 12, 2011

2 stroke oil lubes injectors. It also has combution enhansers in it that allow it to burn in a gas engine. In your truck the enhancers allow the fuel to burn more completely . This is the same reason peaple use propane or CNG on trucks. It is not the BTUs added by the oil but the complete use of the BTUs of the fuel already injected. I drive truck for a living and have used 2st oil for about a year now. My milage has gone up .25 to .3 MPG, This dosn't sound like mutch but to someone geting 6 MPG it adds up. It works for me, but results may vary.......