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Increased diesel mileage

I have a 2007 HD and have added a K&M air intake and a hyper tech tuner set to level 2. I have seen about a 5% increase in mileage. Several folks have told me that the banks full exhaust , air intake and tuner would increase the fuel economy even more. The total package would run $3000.00 which if the increase in mileage is true would pay for itself in 2 years. The question is does Banks really deliver the increased mileage ?

Keep Dreaming…

You need to find the discussion from a few months back where the Ford diesel owner had to replace his motor (on his dime, well $10,000+, I think) after putting that stuff on and frying the motor. DON’T DO IT!

Banks is a reputable company so if I were you, I would want to ask them to get a direct answer to your question. Banks has advertised in Motorhome magazine for some time so you might want to post your question in Motorhome’s technical forum too.

It was a Banks IQ system that fried the other diesel. Read all about it:

Google “Banks IQ problems” and you get only the above example. After reading the posts, it does not seem clear beyond doubt that the Banks IQ system was proven to be at fault although cause and effect is a red hot issue here; impossible to shake off.

Is that the K&N oiled filter? If so I strongly recommend removing it now and replacing it with a NON-Oiled filter. That said, the original filter is quite sufficient and is not reducing your mileage.

Trying to get more power or better mileage by playing with the intake or exhaust, seldom provides any real gains and often causes problems. The auto manufacturers have long (like back in the 50’s, figured out that a good low restriction intake and exhaust is cheap to put on a car.

If you want to get better mileage, you could try a smaller vehicle and more careful driving.

It’s true that most normally aspirated gas powered vehicles don’t get much from air filters and exhausts these days. But turbo diesels are a different animal. They respond freakishly well to even mild modifications. For a full Banks kit, it wouldn’t be unusual to see gains of well over 100 HP and 150-200 lb-ft. of torque. I’ve seen many a unsuspecting Mustang/Camaro get smoked (literally and figuratively) by a diesel 1 ton pickup.

I tried to find that thread, but I couldn’t locate it. If anyone else can find it, please post a link.

EDIT: Nevermind. I see texases beat me to the punch below.

Even if you ignore the cause-and-effect issue, there is the issue of voiding the warranty and having to deal with finger-pointing if something goes wrong. A vehicle as young as a 2007 model might still have applicable warranties. Aftermarket equipment like this gives the automaker the excuse it needs to refuse to honor the warranty.

Agreed. We can’t necessarily apply what we know about naturally aspirated gas burning engines to turbo diesels. However, I would still wait until all warranties have expired before modifying any vehicle with aftermarket parts.

Since diesels don’t have a throttle as the dominant flow restrictor the other restrictions have more effect on the overall system.

Kind of like resistors in series: changing a 1 ohm resistor doesn’t affect things much if there’s also a 100 ohm in series.

To the OP: not a good idea these days to second guess the engine maker, IMHO