Been getting anywhere from 19.2 mpg on up to 20.1 for the last month or so. I went out of town with my uncle a couple weeks ago and we took both trucks. His is a 03 Ext Cab 4.2 automatic and we had to stop and get gas for his about every 330 miles(he got 16.7) i was still sitting on a little above a quarter tank , finally stopped and filled mine up at 435 miles and it came to 19.4mpg. Im still happy with it

 

That happen when my friend put one in his dodge diesel!


Blocked intake, couldn't breath, causing it blow black smoke all the time and poor, very poor fuel mileage!

 

what tire size are you running?

 

^yeah I would say tire size would matter. Also his looks to be stock size. also he has no lift, so those with big tires and big lifts would suffer in MPG, mine did. i max out at about 17-18 highway (drove all the way to KY and got 17ish) took 3 tanks to get there but I also had a bed full of gear and a cab full of people...

 

275/60/17 BFG Long Trail's

 

I can't bear to read this thread any longer.

 

Just got back from DFW(515 mile round trip) without the tornado and i got 17.8mpg, I lost a little over 1mpg. I have put a little over 2800 miles with the tornado and always got atleast 19mpg. This is the second trip i have taken it off and ive lost anywhere from 1 to 1.5 mpg's.

 

Yeah, how do you think science has made advancements? Just think if everyone still believed in things like the earth was flat.
This isn't nearly as significant but same concept. In science you have a hypothesis. Do your test and if your results dont match your expected outcome you do further testing to (hopefully) explain why. No theory can be proven right, only proven wrong. You can have substantial amounts of data to SUPPORT a theory but you'll never prove one in a scientific sense.

How would I try to explain it?
I'd wonder if the blades aren't forming a trailing vortex. If you think about it, in theory the blades would create a rotational vortex that would not create and evenly spread spinning mass of air. Instead it would cause a "ring" of slightly higher pressure with the core of the air mass having a slightly lower air pressure (hence the name tornado). But then you go down the line to the throttle plate which opens the opposite of a camera shutter with the opening starting around the edge and effectively opens into the middle. Under light throttle like you would have for good mileage you'd have that throttle plate cracked with that slim opening on the edge (right where you'd expect the area of slightly higher pressure to be). Having a cyclone effect make it all the way to the cylinders is pretty hard to accept for plenty of reasons discussed all over the forum but this does seem to be a bit more reasonable for the 5% increase your seeing in mpg.

One easy way to check would be to put in a vacuum guage and monitor that. You would compare the manifold vacuum values while also watching a few PIDs of importance on the evo. You would need to watch the MAF, engine load, RPM and throttle position display. Drive on the same road, same day under conditions almost exactly the same. Match up the RPM, engine load and throttle position. Then write down the vacuum reading at that moment. I would expect that that vacuum be lower giving the engine more air without increasing the fuel. A slightly lean mixture would be the result but I doubt it would be enough to cause damage. The engine doesn't run perfectly at stoic anyway and given enough run time the computer would make an adjustment adding the correct amount of fuel.

But just in case you feel like your getting freakish mileage, consider this. Right now your getting the same mileage as me when my truck is loaded up with a 10 ft aluminum john boat and 50+ pounds of fishing gear in the bed and I'm on a smooth road.

 

A lot of these things were popular when gas was $5 a gallon. For less than $20, this little piece of tin was worth the gamble when we were grasping at straws. Some people spent hundreds on the Fitch Fuel Catalyst, and others were trying to run their cars on home-made hydrogen kits. I even saw a kit for conversion to propane. Then there were all those "miracle in a bottle" additives to pour into the gas tank. Remember the nail polish remover & paint thinner that people poured into their tanks? Acetone & Toluene?

Bottom line is: if a guy believes it's working for him, and we think different, just leave him alone and let him be happy. I invested in a tonneau cover thinking it could improve my aerodynamics, but I doubt if I have recovered $500 in fuel savings from that.

 

x2

That is why I got a programmer and vacuum guage. The combo has nearly paid for itself over the last year or so.

 

Just figured id do a small update here, just got done with another long trip. Filled up and got 426 miles when the low fuel light came on so pulled over and it took 21.2 gallons. 20mpg . This was all interstate driving on I-10 running 80-85 mph for about 70 miles (speed limit 80mph), then dropped it down to 70-75 when the speed limit changed. Ive put about 3600 miles on this tornado and always had exceptional mileage.

 

this has to be the all time bull**** thread. how in the hell can you sleep at night. spreading that old west tonic water.

 

Ok buddy, im not sure how you call this a Bull**** thread, along the way ive even posted pictures showing the fuel gauge the odometer and the gas pump. So think what you want to think i will continue posting the results. Your probaly one of the ones that put a 6 inch lift and huge tires and wheels and wonder why your only getting 10mpg.

 

@ his post. I say keep using since you are getting that good of mileage. I would...

 

This is an amazing thread. And I don't mean that in a good way. The laws of physics apparently cease to exist when one of these things is installed. As has already been pointed out the throttle plate is barely even cracked at hwy speeds. Any motion of the air would be stopped and changed when it hits the plate. If you don't understand this place 4 of your fingers in front of your mouth. Now blow and with your other hand feel how much air gets by. Now slightly turn your hand and repeat. Now do it with your hand turned side ways so that your blowing on your index finger. Getting the picture now? Does anyone see how the "spinning" air would be stopped and forced to flow around? Now if thing were located after the throttle plate it may stand a chance of having some affect. Now problem #2 with this retarded thread. Fuel mileage. The only way to properly measure fuel usage would be in a controlled enviorment where temp and bp are the same and by measuring the fuel flowed through the injectors. MPG measured on the hwy are not accurate. A head or tail wind of 5mph or more could have a substantial affect. Not to mention temp, how hard you're on the gas and off, weight in the truck, tire pressure (which temps can play with) traffic, etc.