k&n isn't helping anything either...

Mopar1973Man's Dodge Cummins Articles - BHAF (Big Honkin' Air Filter)

Yeah that's what I have for a filter but I have the k&n 90 that come from the turbo to the filter?!

long as your filter isn't oiled than you're fine...the air tube really doesn't make a difference...it's a looks thing... that factory air tube may be ribbed on the outside, but it is smooth as a baby's butt on the inside.

run your adrenaline on PL1 and it will help fuel economy..

if you have a pulse monitor you can custom tune it as well... I could suggest the best settings in custom tuning for fuel economy, but you really need head studs to safely run that amount of timing.

No it's not oil based. And what's pl1?? And yeah I have custom tunning that I can play with, but idk what to do for fuel Eco?

PL1 = Power Level 1

PL1 is timing only. doesn't add any fuel, just advances the injector timing for better fuel economy.

if you decide to get head studs, you can advance the timing to 10* @ 100% scale with stock injectors and get cooler EGT's, better fuel economy, and more low end torque at the cost of top end power which will be slightly reduced, but the mpg, egt, and torque gains are worth the cost...

downside is it will eventually pop a head gasket if you don't either retorque your head bolts, or get head studs on there...

if you have aftermarket injectors and turbo(s) you will want to run 10* @ 40-60% scale so it will back off timing in the upper RPM range to have better power in the higher rpm range and reduce/eliminate surging.

:pca1:

Crawl under the back of your truck,look at the rear diff, it should have 1 or 2 metal tags...probably very rusty. One of those 2 tags will have your gear ratio. Should say something like 3 73 or 4 10. That same tag will also say what size your axle is.

If you run narrow tires and not driving it like a drag car will help your mileage. Having your front end aligned can also get you 1 or 2 mpg. Keeping your RPMs at around 1800 will keep you in the engines sweet spot. About 1800-1900 is where Cummins makes its peak torque.