Overdrive question
#2
Its up to you. According to the sun visor on my truck it states you should turn overdrive off when towing more than 50% of the trucks rated capacity. I never take it out of overdrive. In fact if Ford intended for you to have it off in city driving then you would have to turn it on vice turning it off. Hope this helps.
#4
I Like Tires
Leave it on unless towing like others said. It will net you better city mileage. I can lock my Torque Converter as slow as 35mph and be cruising through town at ~800RPM. I can see 22-27mpg on the instantaneous when cruising between 35 and 40mph.