I just picked up a 2002 in December, 95k miles. I've only put 250 miles on it, but the computer is telling me I'm at 11.5 mpg. I have put in about 20 gals too. I figure I need more miles to get accurate, but I thought the diesel did better than that. Is the computer right?

Most driving has been city, and it is winter diesel here in CO I expect. Air filter is new, fuel filter is new, tires are properly inflated.

Any thoughts for the new guy?
Thanks!

 

The only way to know for sure is to hand calculate the mpgs...you can calibrate your overhead console to the hand calculations to see how you compare...but you should also get in the habit of resetting the overhead console with new fill ups as well.

Does your Ex have stock sized tires on it? Meaning 265/75/R16's?...if not...your speedo will be off and your mileage will be too...whether hand calculated or via overhead console...

BTW...mpgs are a very subjective thing...first internet liar never stands a chance in the mpg wars!

Joe.

 

Hey Joe, yes, stock tires. I'll definitely be tracking manually also, just seems a bit low. I picked this up stictly for towing needs, family of 6 and a toy hauler so I understood what I was getting into.
Everything I read said the diesel got better mpg than the v10, but that doesn't seem that much better. I'll repost after another 1000 miles or so.

 

Honestly it does seem low for a 7.3L. Have you checked the air filter?

Also check out the 7.3 forum those guys may have some good ideas for you.

One thing to check is the 4x4 hubs...you may have one that is stuck in the locked position causing extra friction on the system...you can reach behind each front wheel and see if you can free spin the half shafts behind the wheels...they should spin free...if not...you have a stuck hub causing drag which will definitely lower mpgs...just a thought. The 4x4 hubs on these can be problematic with their vacuum activation for locking and unlocking. If you have a stuck hub...see this link and select auto lock hub lubrication Welcome to guzzle's Ford PSD Maintenance Web Page

Good luck,
Joe.

 

Thanks Joe, air filter is new. I did take your advice and checked the 4x4 hubs, they spin freely but that was a good suggestion!

I'll post back on this in a few months. I suspect dirty injectors or possibly clogged up exhaust. Will see if I get some improvement once we get off the winter diesel too.

 

what is your axle gear ratio? axle code is on the door tag

 

Get a bottle of Diesel Kleen and get on the interstate and run it! It will clean itself out after a few times. There was a post out there about a week or so about fuel additives. I belive in them, been giving my sd and ex a shot when ever I fuel them up. I know I posted before I put close to 500 miles on my 99 sd everyweek, not so much on the ex. I usually one of three things in the tank. Outboard motor oil, new transmission fluid or Diesel Kleen. Have been doing this for at least 2 years and had now problems. Good luck and let us know what you do.

 

Hey DJ, Axle code is C1.

5150, def going to go with some Diesel Kleen too.

 

KMUL, where are you at?

 

Do ya mind me asking what how much ya paid for it???

C1 is the 3.73 Limited Slip. so you should be on the higher end of the MPG scale as opposed to those with 4.10 or 4.30 for example... I haven't done a second fillup as I just bought my Ex 2 weekends ago. but did initial fillup and reset lie-o-meter... says I am getting around 16mpg (conservative driving).. Verified my vehicle speed with GPS too; all local driving... I have the 3.73 rears too. You definitely have something going on... I am located near Colorado Springs. If you wanna come by we can hook up my Genisys scantool and see if any stored codes... can also check exhaust back pressure, can also check boost. etc...
I would check and see if you have a leak in the valley where the turbo and fuel filter are... if you are leaking diesel there it will drip down the weep holes and around the tranny bellhousing where it joins the engine...
an air leak in the intake preventing full boost could affect your mileage too. Def consider getting a set of gauges.. EGT, boost and Trans temp... 11.5 mpg pulling a trailer would be a reasonable mileage.....
.

 

I live in CO.

DJ, I just might take you up on that. I live in Parker, and I come down to ColoSpgs frequently, I have family there. I bot it from a dealer for $15k. I thought I've been driving conservative, so it sounds like something is up. The dealer said they checked it all out before selling it to me, and they did have to fix a few minor things.

Would a restricted tailpipe cause bad gas mileage? When I bot it, the somebody had obviously backed into something and hit the tailpipe, it was bent almost into the rear wheel. They bent it back, but I can still see a "kink" in it, but I didn't think it was that bad.

 

All 7.3L PSD's came with 3.73 rear diffs, unless they are dually's. So all 7.3L Excursions are 3.73's from the factory.

Agreed. And all good advice regarding possible issues.

Stewart

 

4000 km of driving ( holyday ) in Norway and Sweden , with smal camping trailer ( 750 kg ) . speed limit in N and s is 90 km/h highway .
Milage 17 mpg
arne s
www.fartssperre.no

 

Are u converting to Euro or US gallon?? Didn't know they sold Excursions in Europe... Or did you have it imported?

 

a "kink" should not make a big difference but the stock exhaust does have a lot of restriction..(not as bad as my 4700). One of the first and best mods most folks will recommend is adding a 4" downpipe and exhaust... U can check mine out if you come down. If you are not mechanically inclined and want to pay someone to do it or any other work, my rate is $40 hr. (advice is always free).. I am Mr. Mom so its what I do to cover the bills...