Adding 2 stroke oil to diesel fuel
Adding 2 stroke oil to diesel fuel
(OP)
Hi,
I seeking some factual info - good and bad - on the current trend thats sweeping across all the car user forums on the web - adding 2 stroke oil to diesel. I thought this Forum could add some reality to all the "its works for me" type of posts you read elsewhere (Google it, they are endless !).
Its the new snake oil - or is it ? I've actually tried it in my Nissan TD42 and it does seem to have an effect. The engine is quieter and pulls better. Although I've not proved the lower fuel consumption bit yet, its looking good, certainly not worse.
So whats going on ? Why does adding 2T oil to ULSD suddenly make the engine seem a different beast ? Why does no manufacturer recommend this ? Why does the current ULSD respond to this treatment when the fuel suppliers say the fuel already has lubricity alternatives to the sulphur thats been removed ? Surely if a simple mix of 2T solves problems we need some facts from the fuel makers as to whats wrong with the current ULSD blend ?
Answers guys, and sorry if its already been covered, post me the link, I searched but didn't find anything.
I seeking some factual info - good and bad - on the current trend thats sweeping across all the car user forums on the web - adding 2 stroke oil to diesel. I thought this Forum could add some reality to all the "its works for me" type of posts you read elsewhere (Google it, they are endless !).
Its the new snake oil - or is it ? I've actually tried it in my Nissan TD42 and it does seem to have an effect. The engine is quieter and pulls better. Although I've not proved the lower fuel consumption bit yet, its looking good, certainly not worse.
So whats going on ? Why does adding 2T oil to ULSD suddenly make the engine seem a different beast ? Why does no manufacturer recommend this ? Why does the current ULSD respond to this treatment when the fuel suppliers say the fuel already has lubricity alternatives to the sulphur thats been removed ? Surely if a simple mix of 2T solves problems we need some facts from the fuel makers as to whats wrong with the current ULSD blend ?
Answers guys, and sorry if its already been covered, post me the link, I searched but didn't find anything.





RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
Don't know the exact mileage on my Dodge...Bought it new Feb. 1991 and the odometer "died" about ten years ago at 186,000...I checked the valve lash at 110,000 and change oil and fuel filters regularly. Runs just fine. Certainly has paid for itself!
Rod
RE: Adding 2 stroke oil to diesel fuel
Unmodified oil can be 5,000 ppm sulfur or greater, which is 300 times more concentrated than the fuel. I doubt that 2 tablespoons of anything makes a difference though.
RE: Adding 2 stroke oil to diesel fuel
The keys are: 1:200 ratio. Use a mineral based 2T as sold for saws/mowers (cheaper the better !) etc and not the boat outboard motor stuff and not synthetic. Don't use it in engines built in / after 2007, althought this is up for debate as users with CRD motors are reporting benefits. I think the key there is not to use it if there is a DPF.
Cheers
Phil
RE: Adding 2 stroke oil to diesel fuel
That said, I'm not sure what would account for a change in the rate of pressure rise given what you've said you've done to the fuel. Things which might be involved:
- change in fuel viscosity and therefore amount delivered, spray pattern, and droplet size
- change in combustion characteristics of fuel (ignitability, injection-combustion delay, etc)
- quantity of energy released (but how much difference could 0.5% make?)
RE: Adding 2 stroke oil to diesel fuel
I don't know how big his tank is, but I suspect it's less than 200qts (probably more like 80qts).
RE: Adding 2 stroke oil to diesel fuel
Using an excessive amount of 2-stroke oil probably won't damage anything on an older non-emission-controlled diesel with no catalytic converter. But I doubt if it will do much good, either.
RE: Adding 2 stroke oil to diesel fuel
Feeling better is probably subjective, based on the above.
Adding unspecified cack to fuel may or may not improve the lubricity of the fuel, but pumps and injectors generally outlive engines. anyway.
I always used to pee into my compost heap.
- Steve
RE: Adding 2 stroke oil to diesel fuel
there are kits for large trucks (mining, etc) that cause the engine to consume a controlled amount of its own oil along with the fuel, so that clean oil can be continuously added and oil changes avoided.
RE: Adding 2 stroke oil to diesel fuel
The two stroke oil is formulated to lubricate when mixed with fuel and to burn with it. The combustion products do no harm to 2 strokes. It could be safely assumed that no damage would occur to a diesel where components are similar. Exhaust emission controls on modern diesels will be different to the exhaust components on a 2 stroke.
In my opinion (without supporting data) the 2 stroke oil will burn as fuel. It may very very slightly add to lubricating properties of the fuel and maybe benefit the fuel pump/injector but almost certainly not to a detectable nor measurable degree.
At 200:1 its effect on burn rate, fuel viscosity and energy content should be unmeasurable.
Any change to perceived performance will be due to placebo effect.
Regards
Pat
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RE: Adding 2 stroke oil to diesel fuel
Well cheaper means more brightstock and less/no polybutene (no smoke), and maybe less dispersant. High molecular-weight polybutenes have been used as anti-misting aids, perhaps arguing against a droplet size effect. Not outboard means that anti-corrosives spoil the effect, which suggests a surface activity effect, but 'not synthetic' seems to exclude ester stocks, which should be more surface active than brightstock.
One may conclude the anecdotally based recommendations seem to be pointing in conflicting directions as to what the active ingredient may be . . .
How might 2T oil affect cetane rating?
RE: Adding 2 stroke oil to diesel fuel
Use 2stroke oil with the following spec:
Low ash < 0.05%
JASO FB/C ISO L-E GC or GD
Dont use fully synthetic
Outboard stuff was a no-no in the European posts, but in the American posts it seems to be OK !
I must admit to not knowing anything about 2 stoke oil specs and there may be typos in the above. There was mention of Mercedes having done some work on this, andI think the above specs may be from that work - dunno ?
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
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for site rules
RE: Adding 2 stroke oil to diesel fuel
You should absolutely never do this in an engine designed for ULSD. At the 200:1 ratio, your catalyst could be seeing 2.5 units of sulfur for every designed 1 unit of sulfur, turning your 250,000 mile catalyst into a 100,000 mile catalyst, voiding warranties, and opening yourself up to other trouble. At a more realistic 50:1 (or other similar 2-stroke type ratio) your catalyst could now be seeing 7 units of sulfur for every designed 1 unit of sulfur, turning your 250,000 mile catalyst into a 36,000 mile catalyst. With one good high-sulfur slug (say you add too much with a low fuel tank) and you can actually brick your catalyst within a few hundred miles (it's at least partially recoverable but the controls won't recover it because they won't know what happened).
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
We have no pollution laws in New Zealand - EGR's are plugged,and cats cut off.
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
To bottom line this-----I don't see, feel or, hear anything different, unusual or strange. Nothing! Nada!
Rod
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
Obviously, the pedigree of the oil is why you felt no improvement. If you had dumped in some Torco, Castrol or really old (like me) Steen C you might have been plastered to the back of your seat.
This kind of stuff has been going around for some time and the Dodge/Cummins (Turbo Diesel Register) folks have pretty much come up with the same results you did.
Yosh
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
To put a slightly different twist on the discussion, whats the best way of adding some sulphur back into ULSD for the old timer motors that need this for lubrication ?
Once you've got the sulphur levels back up (is there a limit ?) do you need to consider what spec of sump oil you use to cope with the new sulphur ?
Or is there some other way of getting the fuel system lubricated ?
Or maybe, I'm just worrying unnecessily !
RE: Adding 2 stroke oil to diesel fuel
- Steve
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
Major costs in the last 18+ years---One LR wheel bearing, one RR brake drum (broken brake adjuster), one RF brake rotor (broken brake pad), one oil cooler hose (abraded) and, of course since it's a 90's era truck, all the paint blew off it and it was repainted about ten years ago. That's it, good truck.
I think I'll just continue doing what has worked well for the last 18 years. Maybe I'll look into fixing the odo. Naw...When the "Low Fuel" comes on I can still go an easy hundred miles and that's plenty of time to refuel. Oh! Did I forget to mention that the "fuel guage" is a bit dyslexic?
Rod
RE: Adding 2 stroke oil to diesel fuel
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How Do EP Gear Oils Protect Against Wear?
EP gear oils contain additives that prevent metal surfaces from cold welding under the extreme pressure conditions found in situations where boundary lubrication prevails. At the high local temperatures associated with metal-to-metal contact, an EP additive combines chemically with the metal to form a surface film that is ductile enough to prevent the welding of opposing asperities and prevent scuffing or scoring that is destructive to sliding surfaces under high loads (Figure 1). Chemically reactive compounds of sulfur, phosphorus and sometimes chlorine, are used to form these inorganic films.
didn't read it ($12): http://www.sae.org/technical/papers/902175
Fuel Sulfur Effects on Diesel Engine Lubrication
Lubricant additives: chemistry and applications
http
RE: Adding 2 stroke oil to diesel fuel
RE: Adding 2 stroke oil to diesel fuel
- Steve
RE: Adding 2 stroke oil to diesel fuel