Mileage not what I think it should be..

[rthomas]

Last week I did a short trip (350 mi) that I've done many times before, the truck seems to run good, it has about 500 mi. on a oil change and a new 6637 a/f. I averaged 16.8, in the past I've done as well as 18.4 on the same trip, I always take this trip during non traffic hours and for the most part at the same speed of 64 mph/2000rpm on cruise.

 

[79jasper]

That's about what I get.
94 f350 4x4 zf 4.10 sclb flatbed dually.
I have a 6637. Straight pipe.
Everything else is stock.
But I don't drive real easy, and don't do a lot of highway driving.

 

[rthomas]

I've never been been very happy with the economy, last fall I towed my 23' TT to the east coast and back and only averaged 9.8 over 6600 miles. Now that I think about it my best mileage may have been with 10% WMO, I've been out for a bit so this was on straight #2.

 

[OLDBULL8]

My MPG is way down from 16 -18 to around 9 now. Changed fuel filter (see fuel filter thread). Got the KN air filter, gonna clean that today. Only got 182K on the clock. Traveled to Alaska, 15K miles RT and got 11.5 towing a 30" 5er. Think I'll sell my PSD and keep my 92 IDI with the GV U/O.

 

[OLDBULL8]

What is that 6637 filter?

 

[lindstromjd]

What is that 6637 filter?

It's a Napa part # 6637 filter. There are "equivalent" filters with different part numbers that are just as good or better, but it's called that because that's what the mod was designed with. It's huge, and the best filter you can put on a powerstroke. All it takes to put one on your engine is a 3" 45* tube and some hose clamps.

 

[79jasper]

I definitely wouldn't say "best," just better.

 

[lindstromjd]

I definitely wouldn't say "best," just better.

Personally, I wouldn't run a K+N under any circumstances. They let too much dirt in for the sake of "air flow". I'll just amend my statement to say "ONE of the best after-market filters you can use".

 

[79jasper]

I hate k&n.
I was leaning more towards the AIS.
And powercore filters.

The ais sells for $300.
I just bought a factory airbox and filter from an 08 f250 6.4, for $50.
Powercore filter, About 5" outlet.

The only downside I have, is I won't hear the turbo like with the 6637.

 

[rthomas]

I wonder how good a power core filter would do compared to the 6637, I think a chipped 7.3 could use a little more, mine will get to the first click on the filter minder the first time i stand on it.