hey guys, i got my new powerstroke last week and put a k&n intake on it as well as 2 1/2inch coil spacers. Since then ive LOST about 3 mpg. Is this normal for an air intake to lose mpgs? or could it be the coil spacers messing up the aerodynamics of the truck?

 

The K&N does not filter as well and you get NO benefit from it. These trucks need to get to 500 hp or so before you can benefit from extra air.

I'll track down a study done that showed the poor K&N performance against a OEM General Motors filtration system. It is very applicable to Fords also since the Donaldson (OEM) Ford filter is one of the best at filtering. It is just a PIA to change, but there are tricks to make it easier and most don't need to change it for 50,000 miles or more. Ford states it will hold 3 lbs of dirt.

There are a few people that will say they got a little better mpg w/ an air intake. Many, many more people that are saying it offers no benefit and will probably let more dirt pass through.

Here is the link:
http://www.nicoclub.com/articles.php?id=180100

 

dang that sucks! looks like ill probably be putting my airbox back on. wut a pain :/
Thanks for the info mark!

 

Yup.

Unless you're into SERIOUS off-roading, put your truck back down; you've already got enough ground clearance that you can go under it on a creeper without jackstands. Screw the "cool" factor. When you get 'em standing higher that stock, you've totally messed up the intended handling characteristics. Also, they're much more prone to rollover with a higher CG, and they generally wear tires much faster.

If you're a new F250 owner, you should know up front that CHEAP tires are $150 each, and it's easy to go well over $200 per tire. Kinda makes you want to make 'em last a little longer.

Plus, diesel here just hit $4.19...... getting good mileage is becoming a serious concern.

 

it could be a little of both. the maf coul be getting thrown off by the filter or even the oil on the element could have damaged the sensor. stock filters are the best option for this truck like bismic said. the k&n filter does flow more air, but for a turbo application, more air means more dust due to lack of filtration. there are some very good aftermarket filters which filter almost the same as the stock box, but the stock filter can hold up to 5 pounds of dirt and no aftermarket can.

 

K&N is junk i sent mine back for a full refund after running there system for about 10K miles................it dusted my turbo real good............so i immeadiatly put the stocker back on, flow plenty of air for me and filters well to!

 

An air intake that flows more can not cost you MPG, its your coil spacers for sure.

 

You had me untill "they generaly wear tires much faster". \

I'll agree if you just slap the lift in there and don't get the alignment checked.

Other than that there will be no ill effects on tire wear due to a lifted suspension .

And yeah, don't expect a lifted truck to handle the same as a stocker!!!!

 

you figured this out how?

 

K&N filters use oil on their elements and the maf sensor does not like oil which can equal worse mileage!!

 

[QUOTE=unrulee]......I'll agree if you just slap the lift in there and don't get the alignment checked. ......QUOTE]

Agreed. The original poster, though, mentioned "coil spacers".... leading me to suspect he stuck 'em in and called it a done deal.

Camber, caster and toe all need to be reset with a change in ride height on a control-arm front end. If it's not done, tire wear will be adversely affected.

 

Excess oxygen gives a more complete burn, so if he truly has more flow it should be more efficient and not less. Also the engine uses less effort to pull air into the engine when there is less restriction.

With my original statement I am giving the OP some credit that he did not come on here complaining about a 3 MPG loss and wasnt smart enough to see the check engine light come on becuase its gummed up a sensor or forget to mention huge changes in drivability from the same as well. The OP also said 1 week, a filter would literally have to be dripping oil to foul the sensor in one week. Lifts are known to foul aerodynamics and someone elses hypothesis about a misalignment fit the bill given the info provided.

 

more air is lean, which means truck runs hotter, which means bordering on detonation/piston melting. diesels dont have to work to pull in air. they will do it no matter what you do, ever tried to stop a runaway????

 

Heat is good, heat is what makes the engine run and run efficiently at that, I dont think a diesel can be too lean, there around 80:1 A/F ratio at idle.

Just because a diesel is unthrottled does not mean that there is no energy expended to pump air in and out of the engine.

 

Welcome to the forum! There's a lot of very good people in here, some of whom you've already heard from.

If this is your first diesel, everything is different now... If this is a subsequent diesel but your first Powerstroke, many things are different now.

Do a lot of reading and ask questions BEFORE you drop another dime on mods... For the most part, we've made the mistakes already for you.

Blessings-

Brian
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