I have a 1989 F-250 with the 460 and 5 speed in it, I'm looking to see if anyone can tell me what kind of mpg gain I would see if I cut the Cat off?

 

ZERO unless its clogged

 

Unless its completely plugged up and truck is running bad I don't think you'll notice any mpg gain by removing it. I've heard some poeple gut them and put them back in.

 

Thanks for the info, I was also wondering what all would be involved in by passing all the smog pump and everything and what kind of a mpg gain I might see there or any other tips to gain mpg for the 460 you all might have. thanks!

 

Headers and a free flowing exhaust will help. What gears and transmission do you have?

 

Sorry, seen it was a 5 speed. What gears are in it? Check all your brakes to make sure they are not dragging. Change all fluids with a good tune up and k&n drop in air filter, not an aftermarket FIPK kit they sell. From what all I know, that's the best you'll be able to do. What are you getting for mileage now?

 

Remove the pump and use a shorter serpentine belt or install an idler pulley in place of the pump.

You won't see any gains unless the air pump is partially seized.

3.55 gears, larger tires, slow down.

 

I agree with what's been stated. I saw my MPGs double when I cut my cat out... 5.5 to 11 mpg. It was plugged, and you'll notice the drop in power and the inability to reach 55 mph if it's plugged.

A good tune up, stock sized tires, keeping the speed low, and properly setup up gears, lubed bearings, and properly set brakes will be the best improvements you'll see for no big outlay in cash.

 

Thanks everyone for your input, right now its getting about 11-13 hwy it looks like, I've only had the pick up for a few weeks now, I'm not sure on what the gearing is.

 

You are getting the HIGHER end of milage, I wouldn't touch a thing

 

best I can get out of my 460 in a 4x4 cab n chassis dually zf 5 speed 4:10 gears is about 10mpg

 

wow, lucky you!

my '97 f-super duty w/460 gets at best 6, and routinluy gets around 3 towing a trailer. you wouldnt think you could flow that much fluid through an injector

 

Yeah, that's about as good as you're going to get. I wouldn't spend too much money or effort trying to get any better.

 

Holy crap! There's something seriously wrong with your truck if you're getting 3 MPG, even towing a huge trailer. Sounds like you have a massive fuel leak or other problems.

 

he's not running a pickup and when he says towing a trailer,his combined gross would probably scare you and i.
5.13 gearing.if he's lucky,4.88's......but he doesn't sound lucky lol.surprising really that all the f-super duty (f450's) didn't all just get the diesel engine.

when it comes to pickups,your largest economy gains will be working on aerodynamics.not focusing on the engine.especially with the 460,where there isn't much to be gained anyway.i still have much to do myself.
http://ecomodder.com/