Increase digits of precision for output variables

I have executed several operations that give me an output variable that doesn't match the values I see by inspection of my plots. For example, executing FindLevel to locate the zero crossing of a derivative yields V_LevelX= 1.00037e+006. On the plot I can see this value is actually 1000372.81. I need these extra digits of precision. Is there a way to obtain output variables from operations in Igor without having the result truncated so severely?
Output variables are created as double-precision floating point. FindLevel uses default general formatting (%g) which displays your particular value as 1.00037e+006.

There is no way to change FindLevel's default formatting, but you can print V_LevelX yourself, like this:
Printf "%.15g\r", V_LevelX  // 15 digits of precision

Print/D V_LevelX