Last year, Ford introduced a new capless direct filling system on the Explorer and has since started spreading it to other models including the new Lincoln MKS, the Ford Flex and the Escape. The system has a number of advantages including the convenience of not having to mess around with the cap. The most important function of the capless system is a reduction in evaporative emissions during fueling. Unfortunately with gas prices on the rise, so are thefts of fuel. More and more drivers are coming out to their vehicles in the morning to that some thieving punk has siphoned the gas out of the tank. As a result sales of locking caps are on the rise at parts stores around the country. Too bad these items won't work for the Ford capless system. Hopefully, Ford will see fit to start applying locking doors to more its vehicles to go with the direct fill system.
Update: Ford's Alan Hall has informed me that that a locking cap is available for the direct fill system from Ford dealers. The locking cap will of course negate the convenience factor of not messing with a cap. The tank also has other measures to deter theft making it comparable to a standard setup with a lockless capped system. It does not however, affect the improved sealing that reduces evaporative emissions maintaining the most important functional aspect of the system.