MLA = microlight airplane
How can the hourly rate be 1/3 of my previous calculation?
Rotax 912, 20 liters/hour at 2 euro/liter. Those are the actual prices here at the moment. This comes down to 40 euro/hour for fuel. If you fly slow, you can manage 15 liters/hour, saving another 10 euro/hour, but that's about it...
Engine fund: 20k engine / 1500 hours = 13.33 euro/hour. You can skip on the engine fund, but one way or another you're gonna pay 20k for a new engine after 1500 hours.
Add the yearly fixed costs on top of that, divided by amount of hours you fly. That's the real hourly rate compared to renting.
So 9.5k yearly divided by 100 hours = 95 euro/hour for the fixed costs, plus the 55 euro/hour for the variable cost = a total of 150 euro / hour.
The fixed cost can be higher or lower depending on hangar fees. Tiedown is cheap, but will require some extra maintenance costs. On popular fields the hangar prices may be as much as 500 euro/month.
Of course, if you calculate a fixed monthly fee, then you can exclude the fixed costs from the hourly rate. But in the end, the real hourly rate is "variable cost + (fixed cost / number of hours flown)".