I usually go in. I have to turn the truck off anyway so that I can hear the employee and vice versa. Usually just as fast or faster. Also, some of the newer drive thrus, especially the McD's doubles, the turns are really sharp and a pia to get around. I think the fuel wasted in line at the bank, the food place, idling at startup for 5 minutes is not worth it. Also traffic lights :-laf