I thought I would start a new thread as I can't seem to find anything specific about this so here goes:

I've read several threads on MPG and from what people describe it sounds like your trip counter changes drastically when going from city to highway. Is this true? Does it happen on a daily basis?

The reason I ask is that my '02 MCS stays at 28.6 even after driving for an hour on the highway. It will only fluctuate a half mile either way. I have seen it reach 32.6 but that was after resetting the ECU and going straight to the highway.

My commute is 20 miles one way and is about 1/2 city (with several major hills) & 1/2 highway. A brutal commute to say the least.

Did the early models have a less active monitoring system or could there be other issues? I've keep the car well maintained and it gets better mileage than when I first bought it but all this chatter with seemingly drastic daily changes makes me wonder. Any thoughts?

 

when is the last time you zeroed/reset it?

mine is a running avg and the longer i let it go without reseting, the less "active" it is

scott

 

I think the last reset was maybe six months ago?

 

I reset the "trip counter", "average consumption" and "average speed" with every refill.

The only time the Average Consumption changes a lot is at the beginning of a refill. My average this year is 27.23 MPG 50/50 City/Hwy... '06 MCSc (~200 lbs heavier than the hardtop).

 

From what I've noticed it also takes into account usage when stopped. You figure if the last reset was 6 months ago that's a lot of data to keep the average where it is.

It's going by your average over six months, not the current tank of gas/trip.

 

I get around 28mpg highway....25 mpg city....that's actual, not what the gauge is showing. The gauge seems to always show 2-3 MPG more than the actual calculated MPG.

 

Perhaps I misinterpreted peoples' real-world findings versus the readout on the trip counter. I suppose a 28.6 long-term average is something to be happy about for a daily driver (if the counter is correct). I wasn't really worried; more curious than anything. I'm going to break out the calculator at the next fill up and see what's what.

Thank you all for the input.

 

I see an avg. of 3-4 mpg difference between everyday & road trips (26.5 / 30.1) I really can't call it city / hwy, because my everyday is about 70 miles round trip, mostly hwy.

 

For a 70 mile commute a 3-4 mile fluctuation sounds about right. My assumption of drastic daily fluctuations is most likely my misinterpretation of people's findings.

It looks like my long term average is really close to what your's would be BlownAway. This gives me warn fuzzies inside.