Has anyone had any luck improving the fuel mileage of an older fullsize truck. in my case a ram specifically. this truck is setup as a tow vehicle (4.10 gears, helper springs, long bed, full bed cap), and Im currently getting apprx 13 ish mpg per tankful (varies depending on various things. it also has a 36gallon gas tank. Any tips on what I should/should not do? it has 170k miles on it so i dont want to do anything to hurt it. im worried that doing the N coast, then back into D may hurt the trans... anyone have input for that? same with shutting the motor off when coasting... I dont want to cause more repair bills than I save in gas if you follow. i will be using an ultragauge on it in a few days that should help me somewhat in seeing what does/does not improve the mileage.