I couldn't believe my luck! Two and a half weeks ago my lift pump died so the dealer hauled it in a changed it out for one of the new in-tank pumps. Got the truck back a couple of days later and reset the overhead then checked it again a couple hundred kilometers later only to notice that my feul economy seemed to have improved significantly! (or so said the computer) I figured that couldn't possibly be correct so reset the confuser again when I filled up next. Again the overhead says that my economy has improved from the pre-lift pump failure! I'm about half way through that fill up and it's looking like the computer is right, I've gained approximately 2.5 MPG since the LP was replaced

Anybody else with a wcky truck like mine or did DC treat me special??

 

Have you tried hand calculating it? My race box screws with my overhead, especially on the higher settings....

 

Waiting for the next fill do do my hand calc's, but just in knowing what I was previously having for mileage at the half tank mark, it looks like it's a 2.5MPG increase no matter which way I cut it. I talked to the service manager about it yesterday and he didn't seem surpised about it. Said that the pumps in the tank are providing a more consistent feed to the system as a whole. Kind of made sense, but still, with that increase I'm all grins! Especially if it holds true.

One other item that he mentioned to me is that they're seeing a lot of strange problems with these trucks with no apparent rhyme or reason. I've dealt with this guy for about six years now, and I know that he calls them as he sees them.

By the way, just to make sure I'm getting a clean baseline I've had the 'Zilla off since I got it back. Hoping to compare apples to apples!

Ken

 

Did they reflash the computer when they replaced the pump?

There are reports that some of the computer reflashes make the overhead read higher but do not change the actual (calculated) milage.

 

Could you elaborate on this?

100 Proof

 

The updated pump requires an ecm flash.....don't know why , but its part of the "update".