you know this might sound like a stupid question but will the ranger ecm support a turbo. I know for one that the MAF sensor isnt the recommended way to go , perferably a map sensor system but then you need to be able to have the ecm read pressure in the intake instead of just vacuum. Your going to need at least a 2 bar map sensor. What Im getting at is make sure that the electronics will support what you want to do or else your spending a couple of grand for an aftermarket ecm and harness.
As far as better fuel mileage, I doubt it, I have a twin setup on my s10 sbc, when I switched from N/a I had to get larger injectors (26lb to 55lb) and she really sucks it down under boost now. Stay out of the pedal and not so bad, but whats the point of the turbos if you dont use them.
And I hope you have some cash set aside cause putting a turbo isnt as easy and cheap as your thinking. I used the cheap twin kit $1000 then the intercooler, piping , silicones, oil system, custom headers, fuel pump, injectors, ecm , wiring harness and little incidentals and your talking easy $4000 +. For much less than that you could swap in a n/a SBF and be above the 3.0 trubo hp. Believe me I thought about a turbo but doesnt seem cost effective. Any gas money your saving is going right in to the turbo system.