Aerotow with Diesel engine?

Some aero-engine and car manufacturers are working on Diesel engines for
use in small aircraft. There are now quite a lot of aircraft types
flying with these engines.

Is there anyone who can say something useful on recent Diesel engines in
glider-towing operation? Practical information (climb ratio, technical
and financial aspects, reliability etc.) would be very welcome. Or a
club where such a towplane is in use or tested.

Thanks for the info,

Olfert
Hornet A7, Netherlands.