2 stroke oil in fuel for economy boost?
 

So I had a friend suggest running a small amount of two cycle oil in my fuel for a small mileage bump. Intrigued and glad skeptical I did a google search and apparently it’s a thing?

https://www.tundratalk.net/threads/a...nd-mpg.163858/

Thoughts? They’re talking about running it like 400:1+ in their fuel, maybe it helps lubricity of the fuel, cleans stuff, whatever? I mean, it’s an oil designed to be burnt and they do run it in rotaries…

Do a site search for 'acetone'. Here's an example post: ecomodder.com/forum: 35% gain using acetone/xylol...

I tested it years ago. Double blind test on my wife's car. Added a 16 ounce bottle to the cavernous gas tank of a 4.6L town car. It appeared to at least improve fuel economy, but not enough to cover the cost of the 2 cycle oil. I would have her run it till the fuel light turns on, dump in the 2 stroke oil and fill it up. Same for the no 2 stroke oil tanks.
I would say yes it can improve fuel economy. And it may be economical for some vehicle and engine combinations.

Naphthalene in gas also improves fuel economy but also cost of materials doesn’t cover the improvement

My limited knowledge of chemistry says they are getting the direct injection droplets modified smaller possibly by reducing surface tension. 2 stroke oil does that somewhat, more so for the aromatic volatile solvents

acetone
 

It's one of the most aggressive 'over-the-counter' solvents. You'd have to be very careful with gaskets and O-rings.
Very expensive.
CRC Manual would have it's mass Btu heating value rating.
HONDA R&D may have used it at the Indy 500 in the 1980s as a motor fuel. Really high octane-equivalency ( high-compression capability ).
Don't breathe it!
Don't get it in your skin.
It's probably a known and registered mutagenic, carcinogenic VOC.
Material Safety Data Sheet probably available online.

I had previously heard of Acetone, Xylene or other similar solvents but didn’t understand how they would help mileage and after seeing what xylene would do to a cup I didn’t want it in my fuel system. The two stroke oil (or possibly rotary premix) seems like a viable idea at no more than an ounce to 3 gallons of fuel if it helps

two-stroke oil
 

1) Scientists would say it's anecdotal.
2) There's no controlled instrumented testing.
3) No numbers.
4) No independent verification.
5) Just subjective commentary.
6) I've never seen fuel 'lubricity' issues mentioned in industry literature.
7) Detergent motor oil will clean grease off your hands. Castor oil, or something like it would not be a surfactant or solvent.
8) A two-stroke engine is lubricated by it's fuel.
9) An automotive engine already has closed, pressurized, hydrodynamic lubrication.
10) Two-stroke mixture enters the bottom-end of the engine, lubricating the big end of the crank, and piston-pin, before leaving the crankcase and entering the cylinder ports, lubricating the cylinder walls before being captured in the cylinder head. None of this occurs in a four-stroke Otto-cycle engine. And I think two-stroke Diesels were discontinued many decades ago.
11) Oil might have a higher heat content than gasoline ( diesel does ), however, at such a 'lean' mixture, I don't know how such few extra Btus could make a 'showing' at the crankshaft and flywheel.
12) I had auto shop all the way through high school, and a junior-college engine-building course while in the military, and instructors insisted that one should NEVER use additives of any type in an automobile.
Caveat Emptor.

Perhaps I should have pointed out the link was into Unicorn Corral?

My feelings about ethanol.

ethanol
 

Whoever sponsored the legislation for this variety of mandated oxygenate probably received attractive campaign financing from the corn lobby in subsequent elections.
I was pleased to see the Methyl Tertiary Butyl Ether ( MTBE ) banned, although we'll pay for it until time ends because of Clinton's Mutual Agreement on Investments.

Don't know about those, but there is a high positive inverse correlation between tetraethyl lead and the adolescent crime rate.

en.wikipedia.org/wiki/Tetraethyllead#Effect_on_crime_rates
Don't eat roadside dirt!

'loony gas'
 

It's falling out of the sky every day a civilian piston aircraft is aloft.
The aero engines were never mandated to receive Stellite intake valves and chrome/nickle valve seats, so they still require low-lead AVGAS.

Think you have the valve materials switched, maybe, and 100/110 "lowlead" avgas has multiples of the car lead quantities. It is lower lead than 145 fuel and 80/87 is not readily available.
20 years ago I was able to have hardened faa approved seats installed in my O-290 lycomming and all the rubber parts were replaced with new style alky resistant AN hoses so I could buy a stc for cars gas.

https://ecomodder.com/forum/showthre...ive-24208.html

For economy boost? That's a big negative for me. The benefit I saw is better fuel pump operation in aged vehicles.

While we are commentating on this: anybody ever add some dawn detergent dish soap to the fuel? If it doesn't clog, but disperses it should have the same effect.

Hmmmm need to take a mason jar and mix me up some. Double hmmmm,, dont have any gassers.

I remember seeing mentions of the usage of 2-stroke oil in fuel to prevent rust in the carburettors of some older vehicles due to the ethanol blends on gas.


Nowadays there are even ethanol-powered aircraft. AFAIK cropdusters in Brazil are now using ethanol more often than AvGas.

catalytic converter poisoning

spicer fuel lubricity test
 

you can look up the spicer lubricity test, an indepen scientific study on the lubricity of additives and 2 s oil was in the top results beating out commercial additives with a much higher price. 2s oil lubricates fuel pump very well, useful if you a diesel car that only takesulsd which doesnt lubricate fuel pump much

Cheers

Jorge

Older Diesel engines used to rely a lot on the reaction of the sulphur content of the fuel with the nickel content of some alloys used in the manufacturing of the pumps and injectors. On a sidenote, as biodiesel is often pointed out as a lube too, maybe it would be interesting to try Castor-based 2-stroke oil often used in racing karts, which may blend well not only to regular Diesel but also to some higher content of biodiesel.

That’s a valid concern except for the fact that my Saturn doesn’t have any cats, they were deleted when I did the header and exhaust in 2019

The consensus preferred is a 1 dollar bottle of walmart 2stroke oil per tank of any fuel in my navistar engined F250, but I think that is a price consideration. Castor oil mixes but doesn't burn (at least in rotary radial engines, hence the scarves favored by the pilots) so it might affect the catalytic converter

Are you sure it doesn't burn? At least the ones meant for kart-racing used to be prefered by DKW-Vemag car owners, as its more accurate mix to the gasoline in Brazil due to its high ethanol content leads to a more complete burn. Maybe in a Diesel engine it's a whole different issue, even though it might work better with biodiesel due to the alcohol which replaces the glycerin.

If you ever were in the exhaust stream of one of those radials, you would be sure it didn't burn after you finished in the bathroom.... I DON'T know about it in karts, I do know all my 2 stroke toy airplane engines spit oily goo everywhere and the same result running it in yard equipment mixed with gasoline. The new synthetic castor oils I haven't tried since the CFO thinks my hobbies are a tremendous waste of her money

I run a ratio of 640- 1 TWC to 87 unleaded (one ounce per 5 gallons) in my wife's Toyota Sienna to lube the direct injection High pressure fuel pump.

There is some evidence that the higher ratios keep the valves and combustion chamber clean.

At worse, I think it's a waste of time and money, at best it will make the fuel pump, rings and valves last longer.

Any increase in MPG is very small, I've done tanks back to back with and without. Sometime the without wins, sometimes the with wins.

Those that predict fouled plugs, smoke, carbon cumbustion chambers are simply wrong if the oil is used at these extremly high ratios of over 200-1.

With what?
2 stroke oils have no anti-wear additives and little to no detergent.

They are also ashless dispersant so there's nothing to plug a cat with.

Over on the ford truck forum, they have been running 2 stroke oil since 2003 in the diesels with dpf and cats, no issues.

MMO and 2 stroke oil may help rings to seal better in a worn or defective engine (like any top end lube)

One other benifit on direct injection engines, where the fuel is directly injected into the cylinder it can wash the lube off the cylinder walls, it might be helpful to have some oil in that fuel for max engine life (200K plus).

I believe the latest 2 stroke oil standard is essentially ash free.

Synthetic? Those which won't cause that visible blue smoke might be ash-free. Recently I spotted a 2001 Aprilia SR50 LC in my neighborhood, and it didn't left any visible smoke, ran basically as clean as a comparable 4-stroke of its vintage would.

Thread shows how a small amout of oil can keep combustion chamber clean

https://bobistheoilguy.com/forums/th....269761/page-2

I put some 2 stroke into our 2008 Hyundai sonata. Seems to like it.
Last time I tested 2 stroke oil was in a car that couldn't tell the difference between ethanol free and e10. It saw an improvement but not enough to cover the cost of the 2-stroke.

I dumped some in in the Hyundai and now it's turning 29 to 30 mpg on the highway at 75mph with the A/C. Last time I saw 30mpg on the highway at 75mph was with no A/C and a strong tail wind. I used a lot, somewhere around a 250:1 mix.

Presumably it would take more latent heat from the intake air in order to vaporize the same volume of fuel with 2-stroke oil added to it, so you'd get more miles per gallon based on that. On a sidenote, did you notice any spark plug fouling due to carbon deposits from unburnt oil?

Well it's doing something. Filled it up and ran 3/4 of a tsnk and the oil went from looking like normal 3,000 miles old oil to getting nasty quick.
Crud from the piston rings and upper piston area maybe?
I hit it hard probably running 250 to 1, but I'm cutting get it back to more like 400 to 1 or less. And switching to cheaper marine 2 stroke for water cooled engines.

Last time I saw the prices for 2-stroke oils, the only ones I could find easily and relatively cheap were recommended for air-cooled engines. Marine oils tend to become more expensive too, just like any other boat supplies...

Running around 250:1 with ethanol free gas I did get some spark knock today at wide open throttle, never heard it before on this car. I'll immediately fill it up with more ethanol free RUG and cut the mix to at least 400:1.

Back when I was considering home made bio diesel, someone mentioned an ounce of acetone per 20 gallons of gas modified the fuel droplets surface tension to be smaller but only on closed to atmosphere storage systems and while the acetone didn't evaporate.

Wouldn't ethanol be supposed to "fix" the octane rating?