That magnet deal is pure BS. Even if you accepted that it increased gas mileaeg 3% (and I don't) that's well within the margin of error of any test you could possibly run.

THINK about it! 10% of 20 MPG is 2 MPG. Therefore an improvement of 3% at 20 MPG would equal roughly 2/3 of 1 MPG!!! There's no way anyone can test for that. FORGET IT.

Those magnet things have been sold to unsuspecting, gullible drivers for 50+ years. I've seen them in car mags for decades. At age 56, i've seen a lot of this junk come and go. The only reason people think they improve gas mileage is because they change their driving habits after they're installed...for a while. Then they go back and drive as they always did.

Repeat after me: they DON'T work. They will NEVER work. There is NO WAY they can work.

If you want to do something productive with your $6, buy a big latte and a cookie and get some energy from the sugar and caffeine.

 

as an update this IS the device i was thinking of.

http://www.fitchfuelcatalyst.com/

click on the published review they have all the stuff that backs them up.

i particularly like this one http://www.fitchfuelcatalyst.com/doc...astructure.pdf

here is the one for our cars 96-06 it ant cheep $250 but that is probably because it actualy works. http://www.fitchfuelcatalyst.com/cfm...E7F52CD63E78FE
from their faq
Q. How long does the Catalyst last? 250,000 operating miles or 5,000 operating hours The FFC is a maintenance-free device.

 

I don't trust their numbers. First thing that pops up is in a lab test they only did 2 tests. They didn't even record the operating environment the vehicle was run in. Even our ISO standards here at work mandate that for our tests we record the temperature and humidity and we're just a pump company. Those tests show nothing of the sort and both of those aspects affect the efficiency of an engine.

But hey... whatever. You can find all sorts of things these days that claim to improve your mileage. The simple fact is that if they actually worked, they would be on your vehicle from the factory, period, the end.

 

So I got my truck back and the dealer said he could not find anything wrong. However, he did tell me that I do have an aftermarket exhaust - which explains why the truck sounds like a '72 Chevelle. Now I know a less restrictive exhaust in theory should improve the gas mileage, but is there a possibility that it's hindering it?

Also the tires are p265/75 r15 and this is stock according to what it reads inside the door jam. Is this unusual for a stock 2004?

Any more ideas?

 

I don't buy a word of it. Not one. I don't believe the reviews.

How hard is it to spell BS???????????????????

But go right ahead and waste all the money you want to on this stuff. You could probably do the same thing by pouring some octane booster into the tank.