On 2007-05-23, Newps wrote:

and you make your own biodiesel at ~$1/gal., would you say the
break even point is acceptable?

I don't know. First off putting $80K into a $50K airplane won't
happen for that reason alone.

I used to fly a c172 trainer that was upgraded from the stock engine
to 180HP. Granted it had to be cheaper than a change in engines that
burn different fuels, but how much different?

Here's the breakdown on the diesel upgrade:

parts: $29k
labor: $46-51k

More of the cost is labor. What's the cost of going from say 160HP to
180HP (both burning the same type of fuel)?

I don't expect to see many folks making a lateral change to diesel for
the sake of economy or range, but if someone wants an upgrade in power
anyway, it may be viable to spend a little more and make it a diesel.
The $80k is not exactly a toss-away investment either, because they
can expect to sell the plane for more as well.

Second the guy who has $80K to put into a 182 isn't the kind of guy
who homebrews his own biodiesel.

Perhaps that's the case with doctors and lawyers who are private
pilots. However, imagine a full-time flight school owner/CFI, who
might often be stuck at the airport 1-2 hours between student
sessions. It's not worth it to go home during this idle time, so they
might as well use the time to make more biodiesel. They would still
charge the same wet fee as they would for gasoline trainers, but the
diesel savings would directly increase profits. At $3-4/gal in
savings, the school would get $30-40/hr more profit on each flight.
And that's assuming fuel costs don't go up, and doesn't account for
the saving inherent in a diesel reguardless of type of diesel. So how
long does it take a busy school to put ~2200 hours on a plane? Unless
I made some gross error, I'd say in ~2-3 years the engine upgrade
would pay for itself.

The school could even gain some business by offering students
discounts for doing the grunt work of making the fuel, thus gain some
business for those who can't quite budget enough to pay regular
prices.

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