Havis estimates a squad car idling at an emergency for six hours would use as much as four gallons of gas. They claim the same car using the IdleRight system would use than one-quarter gallon of gas.
Most of the idling is done by officers to keep all the in car gadgets running and to not drain the car battery. The IdleRight product monitors the battery status and starts the vehicle when the level dips too low (( Source - WCFCourier.com. )) . According to the WCF Courier article, Cedar Falls police are installing the system in their fleet. Police Chief Jeff Olson stated that each of the patrol cars has cost the department $321 in idling fuel costs. IdleRight isnt cheap with a cost of $495 per control module with vehicle specific harnesses ranging from $65 to $136.00 (( Pricing quote via Havis-Shields. )) your easily in the $600 range per patrol car equipped with the technology.
Depending on how long you keep your fleet, this may be a very attractive option.