Newb, gas mileage and exhaust questions

[sizematterz]

Heyeveryone, im new here, my names Clint, i drive a 99 f250 psd crew cab, with a 10" lift and 39.5" iroks, with all my hopes and dreams in it, but my questions are about my wifes 00 explorer sport 4x4 4.0 sohc.

My main and first question, it came from the factory with 4.10 gears, soo how much would my MPG drop if i added 33's or 35's

2nd, would 33's hurt any of my power? i use this for towing our boat

3rd, adding a k/n intake, sct chip and dual exhaust would add me how much hp?

thanks

 

[dreamr]

If it came stock with a 4.10 a 4.56 would feel similar with the 33's.

Mine on 33's with 3.73 was worthless for climbing a hill let alone pulling things. With the 4.56 we are back in buisiness..

As to the engine mods. The manufacturers would lead you to believe that your list adds a good 30-50 ponies
In reality you may see 10-15 depending on the quality of the tune you could get a bit more.
K&N Intake may provide 2 or 3 hp in real life. they claim 12-15
True duals would hurt your performance, but a good exhaust sytem will add another 3-5 hp. The chip will add the rest but more importantly will smooth out you shift points making it feel much more powerful .