I have a 5 hp Nissan on my T/4 that can propel me at approximately 5 to 5.5 knots. It does fine for sailing in the Puget Sound and the fuel consumption is real low. The motor came with the boat when we bought it and it has the 20" shaft. I installed the tilt up motor mount and still wish I had the 25" shaft (UL for ultra long) just to get the prop lower in the water. If someone walks to the bow the prop can come out of the water. I have two options, buy the 5" extension kit for the lower unit for about $250 plus 2 hours labor to install or save my money and buy the 6 hp ultra long shaft model which comes with a charging system for my house battery for $ 1450. If you look for Nissan outboards you might look at Tohatsu outboards too. As far as I can tell they are the same outboards just with a different brand name.