As for custom firmware for the UltraGauge, I am not sure. You would have to look on their website or contact them.ATT. James DeLong. Please have this unit programmed to work with the Cruze Diesel. Thank you.
From my experience and from what @diesel has posted about the Edge CTS, it doesn't function well enough to justify the price of the unit. I personally would stay away from it. The ScanGauge II, from what I can tell, has been custom tailored the most out of any unit to work with the Cruze Diesel.So these are my 3 choices in no order. Sangauge2 ultra gauge em plus. And edge cts/cts2