I have a 2001 F350 CC dually and just hit 204k. This truck used to get around 14-16 mpg. Slowly Ive noticed it get worse and worse. Now it is to the point that its really bad. If I drive the truck hard, I'm getting about 8mpg, and if I completely baby it im lucky to get 11. It has 4.10s with 33's. Terminator T500 HPOP, DP tuner, 5" MBRP exhaust, wicked wheel, AFE Big boost filter. Any suggestions where to start looking? Ive already checked the EBPV tube and I don't have any leaks....

 

Do you have some sort of scan tool to monitor things such as EBP, EOT, ICP, IPR, MAP, etc...?

I am sure Tugly will jump in here and help you out. He has helped a lot of people better their fuel mileage with just making sure their truck is in good running order.

How many miles are on the injectors?

 

You might want to disconnect the ebp sensor. Then unscrew it and clean it out of all the soot. This sensor may even need to be changed out. It is a fairly simple routine, included in this is the cleaning of the tube that goes from the sensor to the exhaust manifold.

Here is a Youtube link for you.

 

No I don't have any scan tools, and I believe they are original injectors.

 

Another possibility is boost leaks. You need to look up a boost leak tester (trey spooner has a video on YouTube about boost leak testers). Between boost and EBP, that's probably where your mileage went. Injectors are definitely a good thing to check as well, but more expensive.

 

Okay. You may want to look into getting some sort of scan tool to watch those parameters. Our Infinity monitor will work well for that and it can datalog as well so you can record the info and reference back to it later.

At 204K the original injectors could be getting "tired". How do they sound when accelerating before the engine oil is up to temp? Do not just go and replace them hoping to solve your issue. You will not be a happy camper if your originals turn out to be perfectly fine.

 

Thanks for the kind intro, Justin.

Like Justin mentioned, a scan tool of some sort is a huge help (like AutoEnginuity, DP's Infinity, Scan Gauge, Aeroforce Interceptor, or similar) . I can point out the last link in my signature, but that alone doesn't get you there. To avoid being made a fool by the MPG ghoul, you need the right tool... and a visit to AE school.

Just like feedin' the birds... I'm spreadin' the corn.

 

Just giving credit where it is due.

 

Like they all said. I would do the EBP clean out. It doesn't really cost you anything, unless you break something.

Here is Trey's Boost Leak Detector video.

 

Something silly that I did that cost me 2 mpg for a while is one of my autolocking hubs was frozen in the locked position. If you've got a 4x4, obviously. Easy, quick, free check. The best kind!

Other than that, EBP sensor + tube and looking for loose or torn boots in the IC system and plenums are good rocks to look under just like these guys suggest.

 

You have DP tuner, so do you have a boost gauge? That might hint at boost leaks. Can you run in stock and get 17psi or so?

 

before or after the intercooler?

 

Good point. I'm measuring it before the intercooler. I think I get close to 20psi in DP stock come to think of it.

 

Here is a pretty good thread I started a long time ago. Thanks to the contribution of many members, it has grown into a pretty comprehensive list of MPG drains.

https://www.ford-trucks.com/forums/1...-low-mpgs.html

 

Wow, great thread Trey. I rode with Rob the other day and he was averaging 19 in his long bed. He's got twice the commute that I do at cruising speeds,so that helps, but my 14.5-15.5 averages (I do drive it hard and in town) are not great. Hutch mod to rid of air, new ICP, up pipes, and a billet wheel, and I think I'll get quite a bit back... HPOP and sticks are probably very tired too.