Exhaust what gives the best in performance and MPG

[cfav508]

Ok so i have this new (to me) 06 v8 explorer. I want to do mods to it for MPG. I have done all the searches and read all the mods. Top 3 are CAI ( a true cold air intake not one that sits in the engine well sucking down hot air) a chip and exhaust.

This thread will be focused on the exhaust.
what is better a cat back dual system or a single system. I know it comes down to back pressure but i have seen where if you take too much away the engine has to work harder hence giving you worse MPG. So my question is what is the best approach?

 

[Sams01XplrSprt]

I got single in and dual out 40 series flowmasters on my 01 sport. A lot of people told me I would lose back pressure and etc. But I like how it sounds eventually I wanna go true dual. I am also lucky cause i still got my spare tire underneth my sport. A lot of my friends wanna put duals like how i got and they cant cause of the spare tire. But its up to u if u wanna go dual or single.