I know what you're going to say, I like the sound so I have a heavier foot.

But I've honestly tried to drive very conservatively and still swear my mileage is 1-2 mpg worse.

Has anybody experienced this with an aftermarket intake?

Thanks for your input!

My guess is that you like the sound so you get on the throttle more, thus using more gas.

Ha! I guess I should mention it's the complete intake, not the drop in filter.

And I read this thing would be loud... but holy crap, it's LOUD!

On a serious note, have your MAF sensor checked/cleaned. It may have been affected with the install.

My guess would be... "More air = more fuel"

Your computer has adjusted the amount of fuel to keep the air:fuel ratio where it needs to be. I'm not sure how long it takes to dial itself in after a change, but I would think it could do it pretty quickly. Sometimes I wish that I had more air (living at 6500' elevation), but I do like my mileage up here better than closer to sea level!

This will be my first winter with my truck. I'm afraid it's going to drink like a college freshman once the really cold air hits.

That's a good thought, I'll have to check it. Thanks!

I've never heard of better mileage because of altitude. I live at 6,000 ft myself and don't notice anything but power loss and 1/4 mile times a full second slower!

The general rule of thumb is that you lose 3% power per 1000' in elevation gain. That reduction in power is the result of decreasing fuel quantities to match the decreasing oxygen content in the air. The stoichiometric ratio for gasoline is about 14.7:1... lower the available oxygen, the fuel has to be reduced to keep that ratio where it needs to be. That's why you have to re-jet carburetors for different elevations... you're controlling the amount of fuel delivered to the combustion chamber.

I definitely get better mileage at altitude, but definitely have less power... about 18% less power than at sea level. Most engine builders in our area use a "correction factor" of about 20%. I am also able to run 85-octane with no issues.

So that Pikes Peak hill climb car sitting at the starting line (~9,000 feet) with 1000hp can only produce 850hp at the finish line! But there's less air so, technically, you need less hp to push your vehicle through the air!! ;-)

I can agree, lots of people forget how hard it is to move an object (car/truck) through (air) at high speed. Each parsec of air has a atmosphere of density when you move faster and faster the density or resistance increases (air is not weightless) so more power is needed, if the air is thinner and has less resistance (high elevation) then yeah it should be a little easier to navigate.... think of the raw power of a tornado...its only wind but it can push a car over, toss it through the air, or blow a house off its foundation... even at 60-85MPH i can feel a great amount of resistance from the air.

~INTERESTING STUFF!

Shadow is definitely on to something. I have had CAI's on all my cars and everytime the tube goes on, the MPGs go down. Dipping the MAF in rubbing alcohol definitely helps but as others have said, you are now sucking in way more air. Your engine recognizes this and is attempting to achieve the same air:fuel ratio that it is programmed to have with the stock intake. More air = more fuel.

CAI can get you hydrolock though

I have a buddy with the CAI on a V6 and his is LOUD when he punches on it. I can only imagine how loud it is on a V8. He also doesn't get any better gas mileage and we're here in the sunny, flat-ass state of Florida. Although he does accelerate much faster than I do, but I've got a V8, so every ounce of fuel saved helps

Thanks for all the input. I think some of the oil from the filter made it's way to the MAF sensor.

Right after I installed the intake, I took the thing to the drag strip. (There was also a guy with an XJ on full width's and 40" tires there, so I wasn't the only douchebag with a lifted SUV running the 1/4 mile) It was tons of fun but I think all the passes at WOT ended up causing my problems.

After cleaning the MAF, I gained about 2.5 mpg's back. I still think it's about 1/2mpg off what it was stock, but I can live with it.

You're friend with a V6 4Runner accelerates faster than your V8 4Runner? I find that hard to believe. Not with just a CAI anyway

I think he just means his friend has a heavier foot than he does.

At the dragstrip here, the V6 about a second slower in the 1/4 mile.