Tuning the fuel mixture is annoying enough. I don't peak my engines out because of this, I find a setting that's lean enough to not over-cool them and give them good power and I leave it alone for six months. Tuning the fuel mix AND compression? Not on my planes!


OS glows are fire and forget. Set the carb in April and you won't have till touch it till October. If you have a winter downtime you won't have to touch that carb until the engine starts to wear a bit. Glow plugs are also pretty fire and forget, a well tuned engine will run for years on the same plug with no issues. I've only read of one diesel engine that is that fire-and-forget, and I've never seen any of them for sale anywhere. There's also fuel considerations, as has been mentioned already. I can buy 15% glow fuel for a reasonable price, but if I want to run diesel I have to brew my own or order it by the quart from Davis Diesel. Lastly, I demand a throttle, I won't fly anything that isn't throttled, and that pretty much means converting an existing engine. Such a conversion puts the engine far above my budget.


If there existed a .40 size diesel that I could set and forget for six months straight, idled well, throttled well, made good power, cost about the same as an OS 46AX, and could be fueled easily and conveniently, then yeah, I'd run a diesel. 'Till then I'll just sit back and enjoy them as a spectator, let someone else burn half a tank fiddling with the compression and all that, which is what I do now.