RUG VS. PUG

[LowGear]

I've noticed that all the formulas for modifying VO are given in RUG.  I'm on the verge of building some modified WVO and have PUG right there in the tractor shed.  Is there some reason that I should pick up some RUG for this project?

Casey

[Carlb]

First off it is cheaper and maybe because PUG has a higher octane rating making it less prone to detonation than RUG it may not be a good choice but I am just guessing at that.

[cognos]

In the low ratio amounts that you are using, and for the reasons you are using gasoline in your oil fuel (viscosity correction), it won't make any difference. There is very little difference between RUG and PUG as far as energy content is concerned. There may be more ethanol or other oxygenates in PUG in order to bring it's octane rating up - depends on regional formulation restrictions.

I still contend it's not a great idea to mix gasoline with your oil fuel - for the safety factor. I'd use diesel. It's compatable, and it has the correct additive package built-in.

[LowGear]

So cognos,

You'd just throw in some cetane booster, mix it at 50% diesel or more (diesel) and call it good enough?

Casey

[cognos]

I would. And here's why you should take my answer with a grain of salt...

I have no empirical evidence to support this. It's only my belief, based on my actual experience with conventional fuels, and what I've heard and read about alternative fuels.

Mixing pump diesel with SVO or WVO - you are mixing two "like" products, that are know to have similar functionality in your engine. The pump diesel has additives that are designed for diesel engines. It already has a cetane booster, flow improver, corrosion inhibitor, biocide, detergent, etc... in it. Just adding diesel may bring the cetane number of the entire mix up a bit. It's impossible to know, without actual laboratory performance testing. But it is well within the range of what passes for my "knowns."

Mixing wih gasoline causes me some problems with safety - storage and handling, I've made my feelings known on that issue, no need to rehash. But I'll never recommend gasoline for this purpose, I can't do it. Gasoline is hazardous, and now you are making your much safer VO hazardous, not for a good enough reason, for me...

But it also doesn't make sense to me as a fuel. You are mixing two fuels with wildly different compostions, distillation curves, engine performance characteristics, and the wrong, wrong, wrong additive package - just to mitigate a viscosity issue. If you then add a diesel fuel additive, you may end up with a chemical additive fight in the fuel... I'm sure it'll work - there's plenty of people doing it - it just seems that it's the wrong way to go about it, in my mind.

Just my opinion!

[LowGear]

Well cognos,

You are not alone but then you are.  It seems to be a belief thing.  A couple of very pro articles came up in my google search but it was with a modern diesel sporting a varible mix RUB - Diesel computer.

Because I'm running a 1986 Isuzu I can probably get away with mixing in 10% if gasoline.  I assume its indirect injection but that's my next information quest.  The answer for now is why do it if there isn't a line of folks speaking in favor of mixing in gasoline.  I am going to stay with the cetane additive. 

Thanks for your input.

Casey

[rcavictim]

I won't add any gasoline to the diesel or heavier fuel oils I store inside my building because it can give sealed tanks unwanted vapor pressure and explosive vapors.  That also goes for small amounts of acetone which can cause vapor pressure and fuel line 'bubbles'.

[LowGear]

Wrong Assumption:

The Isuzu NPR 4BD1 Turbo diesel 4 cylinder I have in my 86 NPR is direct injection.  The 4BD2 is indirect - a later engine.

So how does this impact my WVO dreams?  Is up to 50-50 OK?

Casey