Originally Posted by
flyinkiwi
Our day was way in excess of ISA, being 1037 hPa and 6 degrees C, and the aircraft was only getting around 650fpm in the climb from an airfield elevation of 180' AMSL.
The weight of the Tielert diesel and propeller system takes an additional 200kg bite out of the useful load, meaning that weight and balance, and C of G calculations are absolutely vital. With half fuel and just me and an instructor onboard we had to place an 11kg weight in the rear baggage compartment to bring us back within the loading limit as we had exceeded the forward of C of G limit.
So all in all, saves some money on fuel but in the process turns the C172 into a two seater that needs ballast with just two on board, doesn't climb all that well, and the cruise speeds aren't all that flash either. Not a wonderful trade off in my books.
To top that all off, it's a bloody expensive conversion. I struggle to see how such a conversion would make economic sense to most owners.
You have to be doing a huge swag of hours to make any worthwhile savings. Even then I understand the engine operating costs eat up a lot of the savings. The fuel might be cheap but the engines aren't cheap to maintain/overhaul.