Before tinkering you should develop a baseline. Record all the money you spend on the truck over time. you might be surprised how expensive it really is to drive 8 miles every day.
I would consider getting a bike and riding to school most days and keep the truck for the longer trips. If you can find a cheep camper and a few friends to split costs I could see it being a blast for random road trips and going to festivals etc.
A big dually is never going to be an efficient around town vehicle but they do have their place!
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