Display Update rate?

The rate at which the display updates can be adjusted to as fast as every 1/3 second. 

For vehicles with CAN, Ford, and J1850 VPM protocol, the display updates at a default rate of once every 1 second. For vehicles with 9141 & KWP 2000 protocol, the update rate can range from 1.2 to 2.2 seconds. The 9141 protocol is very inefficient and poorly designed, and the update rate is a function of the specific implementation details of the vehicle. Fortunately for all, 9141 was phased out of existence from 2004 to 2007. R.I.P.   9141 and KWP2000 are generally exclusively found in pre-2008, Non-USA vehicles, for example, Toyota, Nissan, Honda, BMW, etc. 

The performance of the KWP/9141 interface can be improved with the UltraGauge KWP/9141 optimizer made available on versions dated 10/19/10 and later. See the user manual for more information

Alternatively, the refresh rate for 9141 can be increased by avoiding placing Engine Specific gauges all on the same page. Engine specific gauges are all the gauges on the Gauge Selection Menu preceding the "MAF 2" Gauge.
The fewer engine specific gauges on a page, the faster the update rate.

In 2008, all vehicles sold in the USA are mandated to use the very fast and efficient CAN protocol, which can handle an increase refresh rate.

To learn which protocol your vehicle supports: Vehicle Gauge Availability Estimator