Auto Meter 9100 ecometer MPG gauge
 

http://www.pfyc.com/mm5/graphics/new/gn2120.jpg

OK, I've had my ecometer since 24-June-09 and have now gone through four tank-fillups, so it's time for a review.

1) of its four operating modes (MPG-inst, MPG-avg, MPH, RPM), only the MPG-avg seems truly useful (displayed values on the other three modes "jump" around too much to be really usefull).

2) it has a single calibration setting (EFF=XXX) which seemingly affects only the MPG-inst and MPG-avg readings. It comes preset with EFF=100, but can be adjusted anywhere between 60-and-140...and, although the EFF-number entered/displayed is an integer, I'm suspecting that it actually represents a decimal-place efficiency value, ie: 100 = 100% = 1.00, etc.

3) the OEM preset EFF=100 produced MPG-avg readings that were too high:

tank#1 0.893 = (1.00)*(34.1mpg/38.2MPG)

tank#2 0.861 = (1.00)*(32.1mpg/37.3MPG)

tank#3 0.935 = (1.00)*(34.5mpg/36.9MPG)

...so, I tweeked the setting down to EFF=90, which yielded a closer correlation between the tank-fillup mpg value and the ecometers' MPG value:

tank#4 0.887 = (0.90)*(33.8mpg/34.3MPG)

...so-o-o-o-o, apparently, the Pontiac (Toyota) 1.8L (2ZR-FE) engine needs an EFF=0.88-0.90 setting. Next tank-fillup should confirm this.

...although not provided in the owners/instruction manual, here's the basic "calibration" formula:

EFF(new)/EFF(old) = mpg(tank)/MPG(meter)

...so:

EFF(new) = EFF(old)*[ mpg(tank)/MPG(meter) ]

where:
EFF(new) = new calibration number derived from tank-fillup vs. MPG-avg value and old EFF nuimber.
EFF(old) = the calibration number the ecometer had during the test period.
mpg(tank) = value from tank-fillup, ie: mpg = miles/gallons.
MPG(meter) = value from ecomoter MPG-avg display.

4) there are no corrections for distance (MPH) or fuel (GALLONS) values, just the single EFF=XXX value; simple, but not easily "correctable" for multiple changes (tires/wheel sizes, etc.).

5) both the RPM and MPH readings are 3-digits: (a) in 1,000's of rpms, ie: 1.42, so accuracy only to 10's of rpms; and, (b) 64.9 mph...but, both constantly "jump" around by 3 values in the last place, making it a guessing game as to what the actual value is.

...more to come.

Sounds interesting. I wonder where yo got it from.

I'm looking for a cheaper alternative to the Scangauge but I don't want to get into soldering and wiring. It would be much nicer to just plug into the ODB-II port. I really don't want anything other than average MPG.

edit:
I can already plug my Vagcom cable in with my laptop and get some readings, but I can't find anything giving me mpg readings. (cheap vagcom ebay cable, not the real thing)

...ordered it on-line from Big Boys Custom Toys LLC, Enfield, CT...cost $74.50 USD including shipping & handling.

...I'm almost at the point of NOT recommending this device, because, so far, only the MPG-avg mode seems to work acceptably. The other three modes (MPG-inst, MPH and RPM) all "jump" around continuously, never settlling down on a fixed number, almost regardless of what the car/engine is doing.

...I don't know if the problem is with the unit or the car interface (2009 Pontiac Vibe 1.8L with CAN-OBD-II) and little help comes from Auto Meter (they were VERY prompt in responding before the sale, but are now disturbingly silent after the sale). I'm trying to find out if others are having similar problems either with the unit of with the unit installed on Pontiac Vibes and Toyota Matrixs and Corollas.

...the good news, however, is that once "calibrated" the MPG-avg reading displayed at the end of a tankfull of gas is quite close to the actual tank-fillup value.

...what vehicle are you thinking about installing it on?

Old Tele man -

I can see the MPG jumping all over the place, but the RPM and MPH should reflect what's happening on your dashboard.

It's too bad. A pretty product that doesn't seem to deliver the goods.

CarloSW2

...while driving with cruise-control set at 65 mph, on flat/smooth highway, both the RPM and MPH displays continuously "jump/drift" up/down, ie:

65 mph (speedometer) = 64.4 - 65.0 - 65.6 mph on meter
2700 rpm (tachometer) = 2.68 - 2.70 - 2.72 rpm on meter

...the road is perfectly flat, there were no other cars either in front or beside me (I drive to work VERY early in the morning). And, I cannot detect ANY actual up/down changes in either speed or engine rpm (seat-of-pants or dash gauges), but the ecometer continuously cycles up/down by about 0.6 mph and 0.2 rpm.

...only the MPG-avg display is "constant," with understandable periodic changes resulting from traffic (truck windstreams), wind, road grade/slope, stoplights, etc.

...and, the MPG-inst display is even worse, with values randomly swinging between 99+mpg and 2mpg popping up under same conditions as for RPM and MPH.

...I'm on my fourth e-mail to Auto Meter asking "what gives?" But since the last two weren't answered, I'm not "...holding my breath...".

Old Tele man -

That sucks. Last year I was doing some data logging with a different OBDII gizmo, and I got pretty regular data :

This data was sampled between 1 and 5 seconds. The sampling depends on how quickly the ECU/PCM returns the request for data. The above boils down to :

HOWEVER, the above data was not gathered with an eye on your observation. It's not continuous, I sorted it for you to see.

If I get the chance, I will attempt to replicate your test conditions, albeit at a lower speed, and see what I get.

CarloSW2

...I work with digital "instrumentation" and am aware there are three obvious areas where problems can arise: (1) sample-rate, or how fast the data are gathered by the cars' mpu, (2) output-rate, how fast the resultant data from the car's mpu are placed onto the CAN-bus, and (3) read-rate, or how fast the ecometer attempts to "read" the data from the CAN-bus...however, the CAN-bus itself is synchronous.

...and, since the "delta" in MPH readings seem to be a 'constant' 0.6-mph value, it could also be a problem with "how" the ecometer 'chip' translates the data that it's gotten from the CAN-bus.

Hi, I have the autometer 9100 and I'm not seeing the jumping around that you are reporting, so you may have a bad one. I have mine on my 08 Ranger.

John

dyerjg -- "Thanks," for the input...so far, you're the only 'user' to report that what I'm seeing isn't "normal." Knowing that it shouldn't be vs. proving it are two different things.

...now, if I can just find someone using one on a 2009 Vibe for specific confirmation (positive or negative). ...again, very little response from Auto Meter, so I'm making sure I've gathered all the facts that I can.

...just did my seventh tank-fillup(s):

tank#5 0.890= (0.90)*(34.3mpg/34.7MPG)
tank#6 0.905= (0.90)*(35.5mpg/35.3MPG)
tank#7 0.930= (0.90)*(36.9mpg/35.7MPG)

which (surprise, surprise) are all well within my acceptable 'tolerance.'

...I really, REALLY, would like to be able to recommend this thing, but just can't get enthused when only 1/4th of the functions work acceptably...although, for 'driver re-training' it's doing a darn good job...just wish the "other" 3/4ths would work well.

do you have a picture of it in your car thinking about buying it but would like to see how it looks in a car/suv/truck

Calibrating the Ecometer
 

I have installed the Ecometer in a 2009 F-150 and the av. MPG reads high, as most seem to do. I have misplaced the instructions on how to 'calibrate' the device. Could anyone post those instructions for me? As I recall, I need to briefly unplug the device from the truck's computer.

Also, just one time, the 'av MPG' seems to have reverted to a lower number. It did not appear to be a 're-set' since the readout did not change (except over a prolonged period of time) making me think that it was still taking an good average reading, but at that suddenly lower number. I had been comparing the Ecometer with the truck's internal av. MPG readout.

Thanks for your help!

...there really isn't a "calibration," just an "efficiency value"--100 is what it comes with from the factory. I had to lower it to 90 for the Vibe.

...the Instruction Manual is needed because it's NOT exactly intuitive as to what must be done to set/reset the "efficiency value"

ecomater MPG gauge
 

O.T.M.,

Thanks for the reply.

I don't have the instruction manual anymore (misplaced) but I think I recall reading that the thing needs to be unplugged from the truck's computer while some sequence of buttons are pushed, after I have calculated the 'factor' that needs to be applied.

Can you post that part of the instructions from the manual?

Thanks.

If your ecometer displays a different average MPG value than your calculated value, you can fine tune the ecometer to match the condition of your vehicle by following these steps:

1) Unplug the ecometer plug from your vehicle's OBD port.

2) While pressing down the left button on the ecometer, push the ecometer plug back into the OBD port on your vehicle.

3) The display will show DSP or EFF depending on the type of sensor the vehicle has.

4) If the display shows EFF proceed to step 6. If DSP is on the display, presss the right button once, the current engine displacement (in liters) should be displayed.

5) Press the left button once.

6) The display will show EFF.

7) Push the right button again and the display will change to a value. The ecometer comes pre-programmed from the factory at 100.

8) If the ecometer is calculating too low of a MPG value, push the right button and hold to increase the value to read between 100 and 140. After you have selected the new vehicle efficiency value, press the left button which will save this value and return to operating mode.

9) If the ecometer is calculating too high of a MPG value, push the right button and hold until the display shows a value between 60 and 100. The display will first move from 100 to 140 and then start increasing.

10) Re-run the verification procedure (gas-tank fillup and MPG calculation).

Ecomoeter MPG gauge
 

O.T.M.,

Those instructions were exactly what I was looking for.

I am reading too high at this point and will make the adjustment prior to the next fill-up & will let you know in about 500 miles after that.

Thanks for your help!

...hope you have better luck than I did.

...I'm beginning to suspect the problem was due to the Japanese electrons used in the computer (wink,wink).

I just got my ecometer today and i also notice alot of jumping around on the instant MPG and RPM. Also some sort of a delay when i accelerate hard ill see the red bars 2 sec later. as for the avrage mpg ill have 2 wait and see. i have a 2006 toyota tacoma 4cyl

Anything new to report?
 

I'm just hitting this thread to ask if any more positive information has been gathered on this unit. I have been looking into buying one, but I hesitated after reading this thread. Maybe a plain old vacuum gauge would be a better use of my $$. Those are a bit cheaper anyway. The plug-in installation and general 'geek factor' kind of pulled me in this direction.

Oooooh, a shiny thing . . . . . . . :cool:

Try this....I will be getting one. Plugs right in on 96 and newer cars:

Kiwi MPG - Diagnostic Computer Saves Gas, Improve MPG, Fuel Saver, Reset Engine Trouble Codes, Drive Green

...it would really be useful to see a "side-by-side" comparison table on these three units, the Kiwi MPG, the AutoMeter 9100 and the ScanGaugeII.

...as they say, "...every dog has his fleas...," and so do different MPG units.

...anybody seen a published "table" comparing these three MPG units?

autometer
 

I have used autometer on all of my trucks, I love them

So...here is a qwuestion for you all....is 99.9 the highest mpg that can show up on these units, or are they limited to something lower. I WILL NOT get near that with my Geo, but have been getting from 52-61 depending on the conditions and how it is driven. I'd hate to buy something that has a limit of 40 or 50 mpg....anyone know?

AND...
I need to update my sig....the SRT4 has ran a 12.17 at 115 mph still on street tires and 93 octane fuel; the Voyager now gets 26 mpg with only replacemnt of the stock air filter with a three layer home made section of screen mesh; the Geo gets a max of 61 mpg, not 63....AND, I won the Stick Shift Nationals in October to raise my number of NHRA/IHRA Championships to 36, using my mechanics plain jane Neon while I was awaiting parts for the twisted in half input shaft on the SRT4 at the next to last race.

Decelerating in neutral at 140km/h with the engine running I saw a reading of 292mpg in my old Pontiac Vibe.

On flat ground with a steady throttle at freeway speeds I can keep the instant mpg reading from jumping more then .2mpg.

I found that with my winter tires I had to up the EFF number to 93 to keep a relativly accurate reading.

Thanks...that's the info I was wanting.

Since I traded in the Vibe, the ecometer has had a new home on the dash of the Silverado. Still works great but one thing I noticed is that, in the Silverado, the instantanious reading doesn't jump around nearly as much as it did in the Vibe. That can probably be attributed to the fact that (at least with the manual transmission Vibe) the throttle is EXTREMELY sensitive to any change in position. 5spd stick w/4.31 final vs 4spd auto w/ 3.42 final. 2.66 times the displacement...

Still, for what it is and what it does, it works quite well.

Autometer unstable?
 

I have a Factory computer onboard, and even starting my tripcomputer at 50 miles/h with cruise control (electronic), the instant fuel consumption is highly variable, even in an apparently flat pavement.

Only average mpg is representative. The other is illustrative as show you instant changes of pushing the trottle, climb or going down slope.

The fact autometer varies instante mpg means it is GOOD, not bad. If it didn´t varies its real time mpg, should be lying.

Oldbeaver

Jumping fuel flow meter
 

Your meter is very accurate as instantaneous fuel consumption IS variable due to many factors. Only mean mpg tends to be stable in ANY good flow meter.

What are the connections it needs? Is it a OBDII meter? Or is it of more general use? Price?

Oldbeaver

The Auto Meter 9100 plugs into and uses the underdash OBD-II connector.

FWIW, the ScanGaugeII™ meter is MUCH, MUCH smoother in its displays of both instantaneous- and average-MPG values...and-d-d-d, it does NOT drain down the car battery when the car isn't used in a week.