MPG - Gotta be wrong....

[CONCH]

Our "new to us" LR4 has an issue with codes P2178 & P2180 - banks 1 and 2 running too rich. Goes in the shop tomorrow as I haven't been able to correct the problem with shop manual suggested issues. Anyway, the LR4 is supposed to get 15 mpg city and 19 mpg highway. But my dash is showing low and mid 20's, even tho it is running rich per the computer. So I'm wondering if others actually get better than the advertised mpg around town, or is this another indication that perhaps the ECM is bad?

 

[ftillier]

Mine lies by a few miles per gallon vs. manual calculations. I haven't adjusted it to read true but it's on my list of things to do.

 

[CONCH]

Mine lies by a few miles per gallon vs. manual calculations. I haven't adjusted it to read true but it's on my list of things to do.

Wait! It can be adjusted? So if I do some math after some trips (actual miles driven / actual gallons used) I can "correct" the brain somehow? Hopefully without a GAP.

 

[f1racer328]

Wait! It can be adjusted? So if I do some math after some trips (actual miles driven / actual gallons used) I can "correct" the brain somehow? Hopefully without a GAP.

You need a GAP tool to adjust it, or possibly the Land Rover SDD tool, but I'm not familiar with that one.

Mine was about 15% too optimistic. I use fuelly.com on every single fill up to track expenses and MPG.

 

[scapistron]

That's so high I'd think you're running on half the cylinders.

 

[16FujiDisco]

@f1racer328 +1 for the fuelly app. Been using that for multiple vehicles going on almost 10 years now; when I started on android it was called ‘aCar’

 

[TheCrimsonCrawdad]

Our "new to us" LR4 has an issue with codes P2178 & P2180 - banks 1 and 2 running too rich. Goes in the shop tomorrow as I haven't been able to correct the problem with shop manual suggested issues. Anyway, the LR4 is supposed to get 15 mpg city and 19 mpg highway. But my dash is showing low and mid 20's, even tho it is running rich per the computer. So I'm wondering if others actually get better than the advertised mpg around town, or is this another indication that perhaps the ECM is bad?

What was the ultimate solution for your ‘too rich’ situation?
I can’t figure out ours, although different codes (P2188 & P2190), maybe be similar enough to help me figure it out! TIA

 

[itsaguything]

An imperial gallon is 20% larger then the US gallon... at which point, you have poor mileage ;-)

As opposed to relying on the electronics, do it the old fashioned way paying attention to fuel used, and miles driven. Tell us what the calculator says.

 

[powershift]

Land Rover uses their own algorithm, its not the one everyone uses with a calculator with miles driven and gallons used. Instant MPG is useful when driving down a grade because when it hits 90 or whatever max it shows that is when I turn on the AC for maintenance for free thanks to gravity. The manual says to use it weekly..