Yesterday while driving I did a little comparison of my torque pro volt gauge with a plug in volt meter in my glove box. Now there are 2 voltage gauges in the torque pro . One is CM volts ( I assume control module) and the other is AD volts. I assume the AD volts are more uncontrolled because the voltage was between 14V to 15.5 volts. The CM voltage was always at 13.4-13.5 throughout the 30 minute drive. Also plugging in the volt meter in the glove before start I had 12.5V . The volt meter would also read .2 volts higher then the torque pro.
Next was water temp which I was surprised on how fast it warmed up. I would say within 2-3 minutes it was at 140*F and in 6-8 minutes it was at 195*F. It ran at 195*F +/- 2*F in all conditions and outside temp was 65*F.
Last was the AFR which was at 14.76 during my parkway ride at 55mph with CC on.
It was a great sunny day and the golf was great.

 

I always read the CM voltage on my Torque Pro. 12.5 V before start is a nearly fully charged battery voltage.

My coolant temps also ran around 195 F on flat roads but, increase quite rapidly as I start climbing one of the local canyon roads. In a matter of 2-4 minutes of mid-range RPM driving I am over 225F. AFR of 14.x is perfect for cruising.

I had one issue with my Torque Pro and its adapter, thus far. When I was doing a 200 mile drive in my XKR over varying altitudes, up and over 7000 feet, I had a warning light pop up on my dash while the ELM327 adapter was plugged into the OBDII port. Finally, I stopped the car, shut the engine, removed the ELM327, restarted it and the warning disappeared. Seems like the ELM327 caused some interference there.

 

IIRC, the 5.0 engine was specifically designed for fast warm-up - I think it's because the oil cooler is a water/oil heat exchanger rather than using airflow, so it can actually act as an oil heater during the warm-up phase.

 

Funny thing about the measured voltages, I noticed something similar with my Land Rover, +0.2V difference between Torque and the measurement at the battery terminals. Both with the ignition on 12.6V / 12.8V, and with the engine running 14.2V / 14.4V

I guess there is a bit of voltage drop down the cables to the modules.

 

The 5.0 cars might have a more accurate reading, since the battery monitor sits right on the terminals.