Tow plane types/mods for high density altitude glider towing

On Friday, August 23, 2019 at 9:30:29 AM UTC-7, son_of_flubber wrote:
On Thursday, August 22, 2019 at 11:50:40 AM UTC-4, 2G wrote:

I only consume 1/2 gallon to launch my ASH31Mi motorglider to 3kft (the same was true for the 26e and DG400, and most every other self-launcher that I can think of, well maybe not the Space Shuttle). So, for a 4 hour flight my "burn rate" is 1 pint per hour.

Self-launch gliders are obviously appealing, but I'm curious about their limitations wrt density altitude and turbulence.

What is your climb rate in your typical density altitude?

Do you ever launch in turbulent conditions with lots of sink?

What density altitude leads you to cancel your flight?

What is the highest density altitude that you have launched in?

My ASH26Mi climbs at about 450 ft/m at 9000 ft density altitude. A little better than a Pawnee towing me. At sea level it is close to 900 ft/min. I routinely launch at 9000 density (typical for a noon launch at Truckee) and have done as high as 9999 (that's the limit of the electronic sign at the end of Runway 20).