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I looked into using a diesel engine in an experimental aircraft (US/FAA definition). Unleaded car engines are fairly common in these planes. It turns out that

I looked into using a diesel engine in an experimental aircraft (US/FAA definition). Unleaded car engines are fairly common in these planes. It turns out that Jet-A isn't necessarily good for a piston diesel engine, due to lubricity and cetane number. After enough reading, I decided to stick with unleaded/100LL until the day I can afford a proper turboprop. https://generalaviationnews.com/2011/03/17/jet-a-versus-diesel-fuel/ https://generalaviationnews.com/2011/03/17/jet-a-versus-dies... https://www.thedieselstop.com/threads/jet-a-vs-diesel.62296/ https://www.thedieselstop.com/threads/jet-a-vs-diesel.62296/ Having typed all this, when I was in Afghanistan with the US Army, the tactical trucks with diesel engines all ran on the same Jet-A that the aircraft used. I assume there was something different about that fuel, or the engines in those trucks.

throwawayboise 5y ago
All diesel fuels are lower lubricity than they used to be (due to changes for modern low-emissions diesel engines). If you have an older diesel engine, you can use additives to restore lubricity, but I don't know if they are approved for use in Jet/A for a piston diesel aircraft.
wbl 5y ago
Jet-A is Jet-A. It's the engines: the Army would like to avoid having to schlep around two kinds of fuel that can get confused to disastrous results.
- jacobmarble 5y ago
  Yes, obviously. Safer to drive a diesel truck on Jet-A than a Chinook on diesel.
- sokoloff 5y ago
  The Army is almost surely using JP-8, which is similar but not identical to Jet-A.
selectodude 5y ago
>I assume there was something different about that fuel, or the engines in those trucks. Nope, it's just that the operational lifespan of those trucks isn't long enough for the Jet-A to really matter. It's only a major issue for the fuel pump, anyway. Those can always be replaced.
- gnopgnip 5y ago
  Yep, most up armored Humvee or MRAPs will last less than 10k miles.

throwawayboise 5y ago

All diesel fuels are lower lubricity than they used to be (due to changes for modern low-emissions diesel engines). If you have an older diesel engine, you can use additives to restore lubricity, but I don't know if they are approved for use in Jet/A for a piston diesel aircraft.

wbl 5y ago

Jet-A is Jet-A. It's the engines: the Army would like to avoid having to schlep around two kinds of fuel that can get confused to disastrous results.

jacobmarble 5y ago
Yes, obviously. Safer to drive a diesel truck on Jet-A than a Chinook on diesel.
sokoloff 5y ago
The Army is almost surely using JP-8, which is similar but not identical to Jet-A.

selectodude 5y ago

>I assume there was something different about that fuel, or the engines in those trucks. Nope, it's just that the operational lifespan of those trucks isn't long enough for the Jet-A to really matter. It's only a major issue for the fuel pump, anyway. Those can always be replaced.

gnopgnip 5y ago
Yep, most up armored Humvee or MRAPs will last less than 10k miles.