Alright I need help!! So today I plan to buy a superchip flashpaq for my 2003 Fx4 and I've heard all about them but does anybody know if they are actually helpful? I have bigger tires so I want it to re-correct my speedo and I hope I'll get a little better mpg and maybe more horses but is it really worth the $300?

 

It won't give you better MPG and the added HP is not noticeable.

You will notice more firm shifts and regain any lost power from when you added larger wheels.

You decide if it's justifiable.