How high can you go in a normally aspirated

[kevin]

Hmmm... I am confused. I said I was getting a groundspeed of 110 knots. With an average permanent headwind (joke) of 10 knots, that would be 120 kts, which is very close to the 138 mph that Ernie says is book at 15,000'. Are the rest of you saying you get better than book performance? You are lucky folks...

The normals do just fine at 12 - 13, I flew mine there all the time. Getting to 15 took a while, and I got slower ground speeds than I would like, but yes indeed, it was more efficient. Above 15 I think would be impractical.

I guess the only point I am trying to make is that there is a BIG difference in performance between 10-12 and 15+.

Just my opinion, y'all seem to have faster airplanes than mine was...

Kevin