Advice on aftermarket air filter for '08 F250

Johnp33 · Sep 22, 2012

There is a study available online about the efficiency of different air filter combinations. The very best was a AC Delco filter in a stock housing, the very worst was a KNN. Do not be fooled by the thought that the filter is so much cheaper, the filter is not free, the cleaning and oiling kit is not free.
Personally I would never install any air intake system, If there system is so good they would give a guarantee?

WD40 · Sep 22, 2012

Look up MBRP on Bing or Google.com and find one near you that has a Cat Back Exhaust. Go with a 4in.
Go to some of the PowerStroke Forums and see what others are doing to there 6.4's
Doug

sld · Sep 22, 2012

scrappy isb67 said:
straight out of the box(FACTORY OILED!) installed, drove ~8000 miles and the intake and turbo looked like someone fed it mud, turbodiesels pull too much air for a K&N, they will pull the oil out and then eat the dust that the too dry air filter can't stop.

That is a good point. I have always had gassers.

But I did use a K&N in my supercharged mustang and never had a problem. It only made about 9 lbs of boost though.

scrappy isb67 · Sep 22, 2012

sld said:
That is a good point. I have always had gassers.

But I did use a K&N in my supercharged mustang and never had a problem. It only made about 9 lbs of boost though.

the camero's had similar problems also, the air filter would foul the MAF with oil and cause the engines to run like crap!

94BULLITT · Sep 22, 2012

scrappy isb67 said:
the camero's had similar problems also, the air filter would foul the MAF with oil and cause the engines to run like crap!

A lot of vehicles have problems with the oil of the filter getting on the MAF. Now it is not the big of deal since CRC makes MAF cleaner.

scrappy isb67 · Sep 22, 2012

94BULLITT said:
A lot of vehicles have problems with the oil of the filter getting on the MAF. Now it is not the big of deal since CRC makes MAF cleaner.

sure IS a problem when the oil is in the engine instead of on the filter. it can't stop dirt/dust with its oil in the engine instead of on the filter!

ericher69 · Sep 23, 2012

Johnp33 said:
There is a study available online about the efficiency of different air filter combinations. The very best was a AC Delco filter in a stock housing, the very worst was a KNN. Do not be fooled by the thought that the filter is so much cheaper, the filter is not free, the cleaning and oiling kit is not free.
Personally I would never install any air intake system, If there system is so good they would give a guarantee?

They do (K&N anyway) million mile Guaranty.

http://www.knfilters.com/warranty.htm

Have run K&N in the past with no adverse effects...except for gas mileage; hard to stay off the loud pedal with the awesome sounding intake noise

JJZ 109 · Sep 23, 2012

elginfarm said:
Hi everyone,
I am looking for suggestions on an aftermarket air filter for my 08 F250 with the 6.4L diesel. I am comparing K&M, AFE and others.
Your experiences and advice would be appreciated. I am mostly looking for a boost in MPG.
Thanks, Eldon

Check around on some Ford diesel forums. I found that the general consensus is against K&N.
Although I bought a K&N intake kit for my '97 F Super Duty Powerstroke, I opted to keep the hardware and swap the filter out for a Donaldson paper unit. It's working just fine for my application.