0.00545 which unless I've messed it up is 15deg below the arbitrary 20deg, factoring an increase of 0.6% per degree below 20degC. At least, the Garmin said it was 5 deg C.
The 0.005 value in the guide is really only relevant for aero testing when you want to compare different setups. I was using 0.003117 for Conti Supersonics, but I don't think you're on anything quite as minimal as that?
Yeah, I was <0.17. What are you using for Crr?
This is good for calculating Rho.