Questions & Answers

What is the oil consumption of the UL260i ?

The oil consumption of the UL260i (and of any engine) is dependant on a number of factors:

• The general condition of the engine
  • condition of cylinder walls
  • condition of piston rings
• Engine oil temperature
  • hotter (and thinner) oil will mean more oil gets past the piston rings to be burnt in the combustion chamber.
  • hot oil will evaporate more easily and be carried out of the engine through the breather.
• Engine loading - power produced
  • High power settings mean increased "blow by". This results in higher volumes and increased pressure of combustion gases inside the engine crank case. These gases mix with the oil mist and need to be vented through the breather.
• Type of oil (presently we are using high quality 100% synthetic multi-grade oil. - Motul 300V 15W 50)
• The position in the crank case where the breather system starts.
• The overall design of the breather and eventual oil recuperation devices.

The capacity of the oil sump of the UL260i is 2.5 liters (+/- 2.5 quarts) excluding the extra volume needed for the spin-on oil filter, extra lines and an eventual oil cooler. We supply an air/oil separator as a standard feature with our engine. The small amount of oil which accumulates in the separator flows through a check valve back into to oil sump. The air exiting the separator has no oil mist at all which has been confirmed by the complete lack of oil traces underneath the fuselage of the aircraft.

The oil level in the M106 test aircraft's UL260i engine had hardly changed after more than 20 hours of flight testing. There would normally be some oil "consumption" but because of some small leaks the quantity has been difficult to measure accurately. The second aircraft to fly reported less than 500ml (1/2 US quart) per 50 hours of operation with its' new UL260i engine.