Existential Angst wrote:

I recently became aware that fuel injector cleaner is basically
kerosene..... !! It's also clear that alcohol is freely mixible in
gasoline.

Depends on the cleaner. Some of them have other solvents like xylene,
and some of them have detergents. The Lucas stuff appears to be almost
entirely surfactants with some kerosene to keep them flowing, and it seems
to work well.

In fact, http://monographs.iarc.fr/ENG/Monogr...5/mono45-8.pdf
indicates a wide variety of stuff in gasoline, including aromatics (like
benzene). The tables don't seem entirely consistent, but the point is, gas
is a bit of a heterogeneous mix.

Precisely.

So the Q is: what can one "dump" into one's gastank, and how much, without
gumming up the works? Including all these catalytic converters. Mebbe it's
better to dump stuff in, say, the lawnmower??

It depends how much stuff it is. If anything, one of the advantages of modern
cars over the lawnmower is that cars have feedback control of mixture today.
You won't burn your valves running too lean, the way you might with a small
engine with a carb.

And what do I mean by "stuff"?
Unknown mixes of 2-stroke gas, kerosene, paint thinner, small amounts of old
oil, any combustible really.
You can put quite a bit of fuel injector cleaner (kerosene) in a gasoline
car, on the order of a pint to just a few gallons of gas, and the car runs
fine.
But I'm not talking about a deluge of stuff, just a cup here, a cup there in
a full-ish tank?

In Mexico, I ran my BMW E28 on Pemex Verde when there wasn't anything else
available and it ran the thing as rich as it could and retarded the timing
like mad but it didn't seem to do any permanent damage.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."