I can't seem to get over about 15 or 16 in mine...even on long interstate flat runs (its ALL flat around here) at 70 mph. I guess that's what you get when your pickup weighs 8000+ empty.

 

You are correct in saying I have a 3.55 axle ratio, and I also have a close ratio 5 speed manual w/OD tranny.

 

Hey Sounds good.

Im in the market for a new truck the 89 f150 doesnt cut dowing the 18ft trailer and my integra.

But ive been looking about this site and the 99 and up 7.3 liter with a 6 speed seems to be the way to go...

But i was looking at like a 97 5 speed 7.3 liter.

Anyone have any ideas or pro's cons.. thanks alot

Jason

 

After driving diesel pickups (Cummins, PSD, Duramax) for 25 years I have concluded that I have NEVER seen so much horse manure written about fuel mileage as in this thread. Good grief, a PSD pulling 8000 pound trailers getting 25 MPG. That is hysterical. I went over to look at similar threads on Duramax and Cummins motors and found, no surprise, an equal volume of horse droppings.

There isn't a "powerchip" made that does ANYTHING but change the balance of power output, fuel economy, and engine longevity. Can you get better mileage? Sure...but you'll pay for it in engine life. More power? Sure... But there is a trade-off for every little thing you do. If you do not believe it, you are simply deluding yourself. Go ahead...have fun with that. Just make sure you admit it in the ad when you sell the truck because the rest of us who DO know what we're doing want to avoid your truck.

If you believe that anyone on earth knows more about your PSD than Ford or more about your Duramax than GM, you are making an expensive mistake. Do you really think that some wrench shop down in Alabama knows PSD's better than Ford? Then go buy some STP...or Motor Honey...or one of those miracle air cleaners from K&N...but leave your engine alone so when you sell it the next guy doesn't get hosed by your ignorance or foolishness.

Let's have a show of hands: How many people know how many four wheel drive dynomometers there are in Detroit...mounted in anechoic sound chambers...with vibration sensors, full EGT analysis, and full environmental controls? Ever been there when they torture a truck to death? Been to the proving grounds? I thought so.

Too many of you guys have no respect for automotive engineers because you have no idea how vehicles are engineered and built. Too many think that the OEMs are in some vast conspiracy to defraud you and make you burn more fuel because they are in cahoots with Amoco or design your car parts to fail eight minutes and fifty-nine seconds after your warranty expires. Too many think that some nitwit at K&N knows more about air filtration than Ford or Chrysler. Too many scrap a perfectly functioning exhaust system for some cobbled up pile of junk from Flowmaster or, worse, straight pipes. I guess there is a sucker born every minute but my advise to you is DON'T BE ONE OF THEM.

If this makes you angry, that is OK with me. But for the sensible readers out there just looking for good, reliable advise and information, take my advise: Read your owners manual. Follow their guideance. Live long and prosper. And don't imagine for one moment that you'll EVER see 25MPG in a one-ton dually unless it's on a flatbed.

 

wow, this is an old thread.

 

Yeah, it is. But it is what appears when people search for fuel mileage data. Reliable data that they can use to make a purchase decision. I know...I'm looking to help a friend make that decision and tried to get some good data to support a used truck choice when money is tight and his family can't afford mistakes.

FYI...I am a huge diesel fan. Owned them all, love them all.

 

Welcome aboard! There is tons of great info on this site and don't be afaid to ask questions!

 

This is a......... interesting way to introduce yourself.
Welcome to FTE anyway.

 

Fair point. I could have taken time to introduce myself but didn't.

I am just tired of the constant slamming of OEMs by thousands of people that truly do not know much about how they are designed and built. People go to these threads to try to learn how to make good choices and find endless reams of opinion that is presented as if it is fact. Astounding. No concept at all of how cars are made or the incredible talent and dedication of the people that design and engineer them. I guess I just snapped.

Now I'll go back to minding my own business.

 

ElDiaOctavo- curious if you are basically trying to say that those of us that have removed OEM equipment (exhaust, intake) in favor of aftermarket parts for whatever reason (MPG, sound, power, etc). have wasted our money? I agree that the engineers of vehicles know what they are doing, but they also sometimes miss the target just slightly. Take for example the 99-03 7.3L PSD stock intake- they are well known for sealing poorly and allowing dust into the intake and motor, even without any broken ears on the lid and having it lined up and clamped down properly.

 

I joined FTE 5 or so years ago with the intention of learning the ins and outs of fixing my Ford F550.
I learned a TON of information and that experience was very helpful in the decisions that I needed to make about my truck.
I could go on, but in a nutshell, I've been a professional mechanic for 28+ years now, but specializing in VW and Audi only.
I was able to glean an incredible amount of knowledge by simply reading.
Some of it is BS and a lot of times I've had to take the time to remind less experienced "wrenches" of a better way to do things.
.
If you have some good stuff to share, that's what this forum is all about.
We are all ears here if you want to talk, but ranting will quickly put you on the list of people to ignore, if you get my drift.

 

wow mr the 8th day.. you sound just like my dad, "if it made it better they woulda put it on there from the start, dont mess with it!". i agree to an extent but there are many things on a truck that it doesnt "need" and if they didnt want you messing with it, or they knew it shouldnt be messed with, they have their ways to keep you from doing it. i like options, sometimes it hurts sometimes it does good and either way im gettin 14.5 in my 01' F250 4x4 at 75-80 mph through hill country goin to deer camp. gitrdun.

 

I don't think I meant "wasted your money"...just that there is a trade-off that will cost you money and make the vehicle less valuable to the next owner. You alter the OEM configuration at the very great liklihood of causing harm somewhere else. You get no free lunch - more power, less life; more mileage, less power, less life; more power, transmission trouble, worn u-joints, spline damage; lift the body, change vehicle dynamics and CoG, driveline shudder, carrier bearing failures. There is NO free lunch and assuming the OEM missed the mark is, IMO, very risky business. OEM engineers are very sharp cats - way smarter than most people realize.

And I don't consider isolated situations like intake manifolds or spark plug torque issues to be damming. ALL machines have individual quirks and problems...but I would trust the OEM first to devise the correction and follow their lead before I listened to the aftermarket. The OEM is not out to harm you or damage your truck - quite the opposite. If they are guilty of anything it is trying to earn money...just like me...just like K&N. The question is really why is the OEM gets slammed first. It is just wrong...and it is not helpful to new owners and guys shopping for good, reliable used trucks.

 

That's what I thought you meant, just wanted to make sure.

 

I just got 20 mpg on waste vegetable oil on a highway trip in my truck. I was unloaded and kept it at 70 mph.