Improving Milage - A simple solution?
I recently decided to add a 1/2 a liter of engine oil to my tanks at each fill-up rather than spend all the money I have been spending on Diesel Additives. My uncle has been doing this to his truck for years and always laughs at me when I tell him how much I pay for the lubrication additives.
The suprising thing I found is that my milage has gone up by just over 10% after I started adding the engine oil to my tanks. I have now gone thru three tanks and the milage improvement is consistant. I now do about 40-50 extra km on each tank between fill-ups.
With the price of a liter of 10W30 (or 5W20, or 10W40, just buy the cheapest oil you can get) at about $3.00 per liter I figure I save about $5 to $6 per tank on fuel.
My trucks have always been steady on milage and this is by far the most pronounced increase I have ever seen when it comes to milage.
As to the theory why I am getting the extra milage I would speculate that the added oil actual improves the combustion producing more useable power which caused the IP governor to back off hence using less fuel.
Considering all the ponding the new ULSD fuels go thru during the hydrotreating processes at the refineries I can see how mixing a heavy oil in with the fuel would improve combustion and reduce fuel consumption. Note the additives being sold are typically very light and hence contribute little to improving milage and focus more on cleaning and lubricating (which also will improve milage if your IP and injectors are dirty in the first place)
Fuel savings seem to be more pronounced on my 91' NA motor than my 93' turbo. The 91' has got a fairly new injection pump and injectors. The 93' is due for a new pump and injectors one of these days as they now have 240,000km on them.
Anyways, I will keep adding oil for the next couple of month and then see what my actual longterm increase in milage will look like. I will also try doubling the oil to 1 liter per tank and use heavier weight oils to see if there is any added benefit.
A final note, always use new and clean oil only, you are wasting your time and money with used engine oil on paying for filters, injection pumps, and injector. Also stay away from synthetic oils, not that that would be cost effective anyways and would not give you any $$ savings in the first place.
10% in fuel consumption saving is huge these days with diesel fuel at $5.50 per gallon here in B.C.
Please post back any results if you are planning on trying this on your truck.
Seb.
Seb.


