I drive a 2000 Expy 4X4, Im getting about 12mpg, I have a K&N filter along with a folwmaster (70) is there any truth to getting better mpg with aftermarket headers or supergharger?

 

No matter what you buy for your rig, it will never recoup your money in milege. The difference between 12 and 15 mpg at $1.50/gal is only $2500 for 100, 000 miles. There are no devices you could purchase to change your milege 3mpg for $2500.
The best way to get better milege in one of these is to avoid jackrabbit starts and maintain correct tire pressure.
There are chips sold here that will increase your hp and torque, but they are not designed to increase your milege. Some do claim an increase in milege, but it will not pay for its self, for they require premium fuel.
Superchargers too increase hp and torque, by as much as 50%, but due to the cost, near $3000 and the required premium fuel it will not pay for its self either.

Tony Warren
Nebraska

 

Also keep in mind that you have accessories bolted to that engine.

The AC compressor unit runs virtually all the time if you have it in any position other than panel or floor... it sucked my mileage down a couple miles per gallon (11-13mpg). I figured that out when I read the owners manual and quit using defrost or defrost/floor exclusively to keep the vehicle warm after the window is unfogged. My mileage went back up to warmer weather numbers (13-16mpg).

That alternator also drags your engine down... especially when you have a large amount of lights or high power stereo. Those large draw items cause that alternator to produce more counter EMF than usual (it's always there as the alternator works). Counter EMF is a magnetic field counter to what you want the alternator to produce to make its power. It makes the alternator work harder thus loading the engine down. Think of it as a parachute that gets bigger as you go faster.

Free flowing exhausts and intakes are great, but not cheap. Chips may be the way to go as they can change shift points and timing which allow you get the most out of an engine tranny/combo using the existing engine setup.

-Kerry

 

The idea behind the aftermarket products claim of increased gas mileage is that the gained power lets the motor do work easier. Work being - accelerating or maintaining speed. The reason that an increase in mpg is never seen is because you have to drive like an old fart out on a sunday drive, which noone ever does with their new found power. So, yes there is truth to getting better mpg. Which allows us to rationalize buying these products that we really want for the WOW factor.

 

cjakn its ok. The money you spent on the K&N is worth the money. If not for the gas and sound the filter price for the truck is out of control. As far as the Flowmaster goes... Did it help get it going faster? Then it was money spent well. To save money on gas, stick to the baiscs. good gas,and good spark. The oil changes will help with the gas but it will help with the motor more and then save you money. As far as the AC goes, it turns on more than any of use will ever know. When you go to start your truck the AC compressor gets power if the you have over 11.5 volts. This stops the compressor from filling up with 135a and locking up. \\ford tech CD\\ The old fart thought is there and will save gas but unlike the old fart, I can't be passed when I know that I can take most cars in the 1/8 and 1/4 mile. As you add more to the engine you will add more to go wrong. It's in all of what you want.