What are you towing?
The quick answer is 150hp will work pretty well for the clean and light gliders, and even the training gliders most of the time. Several 150's - 160's towing at sea level. A single place glass glider will be happy behind a 150, but not so much a 2-33 or 2 pax Blanik on a really warm day. It'll do it for sure, but the margin is thin. For a data point, I'm towing here in CO with a Jensen STC'd 180hp PA-18, but that's a different beast. 9k+ DA most of the year (field is at 7k) and even on the cold days performance is meek. Where are you? Are summers warm? What is typical DA? Is there steady wind? With a heavy 2-33 behind you, 5 knots of wind on the nose makes a HUGE difference. Towing off grass or pavement? If grass, is it cut regularly? Towing year round (ie: cold winters, hot summers)?
Keep an eye on engine cooling. Long durations at high AOA, full power and slow speeds can be damaging. Also think about reinforcing the tail brace if you are going to tow regularly. Dodge sells a nice little kit.[/QUOTE
great questions.....Summertime density altitude is usually about 1500 feet deep Southeast. Wind usually 5 knots or more...Grass and it usually cut and fairly smooth. About 3000 feet. Hoping to tow trainer such as 2 seat Blanik