I don't see anything other than some other possible issue as far as the muffler swap and decrease in mileage goes. How are you calculating your mileage? Winter gas?

And to all the old men driving like ladies.. my foot is always on the pedal. Half the people that ride with me ask why I have to drive like I stole it all the time. Not speeding, just love to get up to speed a bit quicker than most. And love the way it pulls too much to drive it any slower.

Still don't understand those who buy trucks, with a v8... only to complain about the gas mileage.... buy a honda

 

we dont need any more of them pos's of the road!

 

Hahaha, you sound a lot like me! Although, I have a hard time NOT driving at least a little over the limit.

 

My FX4 gets great gas mileage when I drive it, the wife has a lead foot cuz she likes hearing the intake and exhaust, that she originally asked "what the hell do you need that for?" .....
PS she drives a '10 civic hahahaha

back OT i saw a small gain in MPG after installing my 14" magnaflow

 

HILLARIOUS

I'm looking to get my truck 'flowin and I anticipate the same kind of response from my wife. Especially once she sees how much $$ it's going to cost

But like your wife, she'll be all over it after she hears it for the first time

 

hide the reciept and lie to her she goin say she cudda bought more shoes and clothes with that money!!

 

Just got 17.50 mpg. No complaints.

 

I was at 16.8mpg avg, 15.2 city 20.4 highway on stock wheels, leveled & exhaust, custom tuned 87 oct. After the 20s & 33" Toyos I average 14.8, 13.7 city 17 highway. Sum beeches are heavy .

 

Hand calculated? Just curious.