Mileage

[Kawboy]

I own a 1999 F-250 Super duty with the 7.3 Turbo Diedel. It gets 8.5 MPG when towing a 12,000 pound trailer and only 14.5 MPG when solo driving. I don't make jack rabbit starts and very seldom do I drive over 60 MPH when solo driving. It is a stock vehicle without any special computer chips or Banks system. Other than an expensive banks system or computer chip that I am averse to using what can I do to get better mileage?

[mrjohnwayne]

better air intake and straight pipe the stock exhaust.

[Kawboy]

John Wane,

It has the K&N air filter. As to straight pipes, I tried a more open system on my old 1993 7.5L gas engine and it screwed up the mileage and power, something to do with how the computer reacted to it. Although when I added Doug Thorley Headers it improved in both horsepower and mileage. Being on a fixed income those headers or a Banks system is not in my budget. So I guess that I will just have to live with it.

[mrjohnwayne]

Sorry let me clarify. When I said air intake I meant the whole system, air box and all. The 99 models (especialy early 99's) where a very crappy design. You can get a new Sever Duty AIS (air intake system) from ford for about 250 which will not only flow much better but also offer better filtration. Trust me if you live in a dusty area this will help a ton. If it is to pricey you can do what I did for now. Get a piece of 4 inch exhaust pipe(preferably stainless) about 4 inches long (most exhaust shops will just give it to you), a 4.5 inch hose clamp, and a 6637 filter from NAPA. You can remove the stock filter and air box and replace with the 6637 filter using the 4"pipe as a coupler. If your interested I'll send you pictures of what it looks like.

Now for the exhaust. Trust me if you straight pipe it you will be happy. Not only will it increase mileage it will help in the power department. It won't be a big gain in power but it will help. The 1st powerstroke I owned (2002 7.3 Crew Cab Long Bed Dually 2WD) I deleted the cat and the muffler and gained approx 60 miles to a tank of diesel. I could get 18 MPG on highway. Diesels are much differnt in the way they run compared to a gas motor with 02 sensrs and computer controlled everything. The more air you can get in and out the more efficient it will run.

[Kawboy]

John,

You certainly sound like an Hombre that has it all together as far as Ford Turbo Diesels go. I will definitely look into the 6637 NAPA filter.

As to the removal of of the Catalytic converter goes, Washington State definitely frowns on the removal of such items, and that is where our truck is registered. Besides, I doubt that my wife would put up with the noise of a straight through exhaust.

We do spend a lot of time in and around Del Rio Texas most winters, but this year we won't be going there till maybe March if we do go south this year. Where at in Texas are Y'all from? We weren't born in Texas, but we got there as fast as we could. Sure do like that Hill country for cruising on my Kawasaki 454 LTD Motorcycle. Especially up around Camp Wood and Vanderpool where the "Three Sisters" scenic highways are and the Lone Star Motorcycle Museum is.

Thanks a bunch for the input.

Hal Thomson,
The Geezy Rider

[mrjohnwayne]

Born and raised about an hour north of houston. Been living in the DFW area for about 2 years now. I agree about the hill country especially around the austin area. Beautiful.

I'm not sure about washington but it is worth some looking into cause most diesels arn't required to run cat's or muffler.

As far as the cat goes you can get a delete pipe and remove the cat, then whenever it comes time to have it inspected/ renewed you can put the old cat back in place. You know best though. If you can get away with it it will help you out.

Sound actually isnt to loud if you keep the stock 3.5" exhaust.

I'll snap some pictures of my setup this weekend and post em up for you to see.

[Kawboy]

John,

Thanks for the rapid reply. I will definitely look into the states requirements. Right now I am in an area that doesn't require testing but should I move to another area, (and we are thinking of doing just that) I may be required to test. What are your thoughts about just removing the Catalytic converter and leaving the muffler installed? And yes I can readily understand your stating that the bigger tail pipe would be quiter than a small pipe. And though I do not want to put you out, I would definitely appreciate it if you would post some photo's.

The Geezy Rider

[mrjohnwayne]

It'll help out if you remove just the cat. I do recommend this, if you leave the muffler then I'd change it to a high flow muffler. Most paces like MBRP, Magnaflow Etc.. offer this at a reasonable price by itself. I'll snap some pictures off but it will be next week before I post them. Leaving in a bout 20 minutes on a road trip but I'll have them when I get back.