richardkf wrote:
KenJennings wrote:
Flying J wrote:
Jeep sees about 100% stop and go traffic, and has been consistantly at about 20 MPG (both hand calc and by the EVIC) since new. Had the F 31 recall and EGR repair done about 60 miles ago and the EVIC is now reporting 17.1! I reset it after I left the dealer.
... Or maybe the EVIC is lying to me.
Anyone else had this issue with F 31? (GD5092 - did your MPG come back?)
...
The EVIC is always lying to me. I calculate mpg by hand with each fill up and the EVIC averages at least 2 mpg higher than reality. I do 90% highway driving and I get the same 21 mpg (real mpg) after the tranny flash that I was getting before the flash. But, now shifting isn't so violent.
The EVIC is not average miles per gallon per tank, it's average miles per gallon from the time you start the CRD. It makes sense that it is a few miles higher than average. If you do mixed stop&go and some highway cruising, you're going to a lower per-tank miles per gallon calculation when you do it manually, and a higher average miles per gallon average on the EVIC since it is basically just for "this trip"
Every time my CRD started the computer picks up where it left off with the MPG estimate. It does not reset itself. It seems to be a continuous "average". The dealer reset the computer twice for TSB flashes and the mileage calculation was reset to the starting point of 16mpg.
The computer does not appear to me to be giving an average or any sort of analysis related to fuel consumption. It seems to be awarding points that it deceptively presents as MPG for what it considers "good" driving style.
When I got the CRD an F350 (turbo diesel) driver told me his driving style for high mpg is to shoot for the lowest rpms that a gear will allow -- the theory being that lower RPMs means less fuel burned. The EVIC liked this this behavior a lot. I was driving around the highway at 59 mph in OD (and 1625 rpms on the tach) embarassed, but getting EVIC scores around 26 to 28. However, every calculation at fill up told me I was only getting about 21mpg +/-1mpg.
Then I hear from actual CRD owners that it works best in the power band from 1800 to 2000 rpms. So, I've been driving around like that for a couple months. So, now I can drive about 65 to 70 on the highway and not get ugly stares. The EVIC isn't so appreciative now and hands out scores from 22 to 24. But, when I hand calculate mileage at fill up I'm still not doing any better than before. Still right around 21mpg, plus or minus.
So, I can't figure out what the people are doing who say they're regularly getting 24, 26, 28 mpg. I can't duplicate it. Maybe they're just reading the computer and thinking its truthful. (I have no extraneous junk colelction in the vehicle. Most of the time the CRD is carrying me and a laptop. So, its not like I'm having problems due to toting around excess weight)
If DC can't get the computer to show real tank MPG, I think they should have it show a 30 second calculation of fuel use extrapolated for some distance. (My father-in-law's car does this.) Maybe just a smiley or frowning face instead. At least then the fill ups wouldn't be so depressing.
_________________
Thanks,
Ken Jennings
2006 KJ Limited 4x4 CRD, Option Pkg G, Lt. Khaki, Built 1 Feb 2006
Tow Package for myself, EVIC TPM
Side Curtain Airbags for my daughter
http://www.kenjennings.cc/crd/dieselexp.html