Read this for basic knowledge. http://www.clearnav.net/Technical/Va...pneumatics.pdf

If you plumb all three lines, then you can try both approaches and see which works better FOR YOU ON YOUR GLIDER. Your results will depend on the location and accuracy of your static ports and glider type, so anecdotal opinions may not be conclusive.

I have a V7 and I love it. A more interesting question to me is 'what do I display?" I set the analog pointer to display average. That forces me to listen to the beep and keep my eyes off the panel. I keep the backup vario turned off. The average lift indication is a very good indicator of when to stay and when to leave a thermal. It objectively confirms my bad old habits of taking too long to center and staying in a thermal for too long.

What is the real value of displaying short term lift on an audible variometer? For me it would only be a reinforcement of bad old habits developed with non-audible variometers.

I'd like to see the Soaring Safety Foundation take a hammer to all of the old non-audible variometers. That would be a great cost-effective boon to soaring safety (and boost the price of used B40s).

I expect that my V7 will pay for itself by reducing my re-light tows and my average tow height.