ScanGuage on Honda Accord Hybrid
#21
03-17-2005, 04:29 PM
I've noticed that even in gear with my foot off the gas pedal, it still never shows less than 0.2 GPH (gallons per hour), but I could swear Hondas shut the injectors off entirely whenever you're in gear, off the gas pedal, and above 1200rpm or something. Maybe switch yours to show GPH and see if it still shows a significant GPH reading, because of all cars, the hybrids should be the ones most likely to have a zero GPH reading when coasting down from 40+mph.
#22
03-18-2005, 02:02 PM
Maybe I'm misunderstanding you, but how could the injectors be turned off if the engine is still running? They supply the gas to the cylinders. I do monitor the GPH guage when driving. And as I coast to a stop it steadily goes down and registers zero when the engine shuts down. What still puzzles me is the MPG guage on the Scanguage. As I slow down the instantaneous MPG readings go down, yet if I switch to the trip guage on the Scanguage and watch the average MPG reading it goes up. How can one go up and the other down? Am I missing something?
Rich
Rich
#23
03-18-2005, 05:06 PM
The inertia of the vehicle keeps the engine spinning. You could take the key out and throw it out the window and the engine would keep turning for as long as the car is in gear. Let's back up for a moment though. Let's say at steady-state, it shows 50mpg for you. When you lift off the gas and coast to a stop, are you saying that the SG instant MPG goes down to 45, 30, 20, 10, etc until you come to a stop? Or are you saying it jumps to 150mpg then decends to 130, 110, 80, 50, 30, until you come to a stop?
#24
03-18-2005, 09:43 PM
I have tried to reiterate that currently the ScanGauge will not work well for calculating mpg on hybrid cars because of several conditions unique to hybrids. This does not negate its use for calculating mpg for non-hybrid cars mpg, or any of the other things the gauge can do though.
The scangauge does not pull the mpg data from a directly from a certain part of the cars computers. Instead it does a generic calculation based on several variables. I don't know all the variables or the calulation itself, but needless to say, I would think the calulation would expect the engine to be using gas when the car is being propeled forward and the engine is turning.
The fact that hybrid cars can do things like coast down a hill with the car on, without using gas, messes with the assumed constants of the mpg equation.
For non-hybrids the gauge seems to do well fo calulating mpg.
But I'd skip it for calulating mileage in a hybrid. In a hybrid I'd use it for all the other features. As noted in people's previous posts, the gauges other readouts work fine on hybrids. I even used it to read an error code and reset the check engine light on my Insight.
The scangauge does not pull the mpg data from a directly from a certain part of the cars computers. Instead it does a generic calculation based on several variables. I don't know all the variables or the calulation itself, but needless to say, I would think the calulation would expect the engine to be using gas when the car is being propeled forward and the engine is turning.
The fact that hybrid cars can do things like coast down a hill with the car on, without using gas, messes with the assumed constants of the mpg equation.
For non-hybrids the gauge seems to do well fo calulating mpg.
But I'd skip it for calulating mileage in a hybrid. In a hybrid I'd use it for all the other features. As noted in people's previous posts, the gauges other readouts work fine on hybrids. I even used it to read an error code and reset the check engine light on my Insight.
Last edited by ericbecky; 03-18-2005 at 09:48 PM.
#25
03-19-2005, 03:45 PM
I understand that the SG does not work for MPG on my hybrid and I don't intend to use it for that. I'm guessing that it is giving me MPG as if the car was gasoline only. I did do some further testing today and it does spike momentarily when I disable the cruise and coast and then heads down. However, even though I was on a flat road and used the cruise set to 50 MPH, each time I disabled the cruise it spiked to different values ranging from 130 MPH to 65 MPH. It's becoming obvious I'm not going to make any sense out of this and am getting too fixated on it. :-) I do like the SG for all the other info it gives me.
Eric, do you know if the hybrid model SG Ron is working on will work with all hybrids?
Rich
Eric, do you know if the hybrid model SG Ron is working on will work with all hybrids?
Rich
#26
03-20-2005, 08:01 AM
I'm not sure what his plans are. I know when I pointed out one of the anomolies he called me back in about 4 hours saying he already adjusted the calculation to correct for it. He bench tested it but wanted to try it on a real car.
To be able to extract car specific codes he needs access to a car. He said it some cases he buys a car, tests it a while, and then resells the car. Unfortunately this probably isn't practical for most hybrids right now, since hybrids are in such short supply. I hope some hybrid owners in the Phoenix area help Ron by giving him access to their cars to test the modifications he is creating.
To be able to extract car specific codes he needs access to a car. He said it some cases he buys a car, tests it a while, and then resells the car. Unfortunately this probably isn't practical for most hybrids right now, since hybrids are in such short supply. I hope some hybrid owners in the Phoenix area help Ron by giving him access to their cars to test the modifications he is creating.
Last edited by ericbecky; 03-23-2005 at 07:09 PM.
#27
03-26-2005, 10:36 AM
Originally Posted by mikemc
I've been using a ScanGuage with my Honda Accord Hybrid the last several weeks. Attached is an Excel file of just a few days of data I recorded with it. With the cold weather, some of the fuel savings features such as "auto stop" don't kick in until I'm almost done with my 6 mile drive to/from work. With the ScanGuage, I can see the instantaneous mileage, fuel flow rate, and other metrics. With regard to the instantaneous mileage, small variations in throttle position can result in major differences in mileage. With regard to the fuel flow rate, in 10 degree F weather the idle fuel flow starts out at about 1.2 gallons per hour. Once the engine is fully warmed up (after about 10-13 minutes of driving), the fuel flow at idle drops to around .2 to .3 gallons per hour. Thus, very short trips in cold weather result in poor mileage. On the one day with relatively warm weather (60 degree F) shown in my data, my mileage shot up significantly.
If you are still logging data, I'd be interested to know a couple of things.
Your 1st excel sheet looks like data collected over short trips before the hybrid features kick in, with coolant temp around 180.
I'm wondering what scan gauge data looks like during the car warmup, and at the precise moment when the car computer says, ok, let's go hybrid. Does SG display anything notable when the hybrid displays come to life? I'd be very curious to know what the data looks like at warmup and pre-hybrid, the moment of hybrid activation, and during a longer run after warmup.
I know, all I have to do is buy one of my own...:=)...
Lewis
#28
03-26-2005, 05:13 PM
Lewis,
As I had mentioned in my previous post, the ScanGauge shows high fuel consumption as the engine warms up. Once fully warmed up, the fuel consumption drops to around .2 to .3 gallons per hour at idle.
-When cylinder inactivation kicks in, the mileage shown by MPG indicator on the ScanGauge tends to jump perhaps 25 to 60 percent.
-When autostop kicks in, fuel consumption drops to 0 GPH (because the gas engine is off)
-As the vehicle slows and the batteries are charging, fuel consumption doesn't drop below .2 GPH and the instantaneous MPG shown is sometimes over 100MPG.
-When accelerating, instantaneous mileage is low (sometimes sub 10MPG).
As the car warms up, some hybrid functionality starts kicking in before other functionality, so there is not exactly any one moment when the car "goes hybrid". When hybrid functionality kicks in, whatever guages you have displayed on the ScanGauges still display. There is no little message that pops up or anything saying that the car has gone into hybrid mode.
My typical mileage is just 6 miles to and from work, though I did take it for a longer highway drive last weekend. According to the instrument panel, I drove a round trip of 82.0 miles at 35.2 MPG. According to the ScanGuage, I drove 80 miles at 36.2 MPG and burned 2.2 gallons of fuel.
So the ScanGuage and the Accord Hybrid's instrument panel were fairly close, though not exactly matching. This was a highway drive to a shopping mall and I had to spend 15-20 minutes driving slowly around the mall parking lot to find a place to park which lowered my mileage somewhat.
I have a StreetPilot 2610 GPS in the car so I'm planning on seeing the trip distance it records when I get a chance for comparison purposes, since the GPS is highly accurate. Last weekend I had the GPS and the ScanGauge both on the dash and my recollection is that I was getting speed readings along the lines of the following on the highway:
GPS: 60.0 MPH
Accord Hybrid's Analog Speedometer: ~59-60 MPH
ScanGuage: ~58 mph
Thus far, my experience has been that the ScanGauge seems to be fairly accurate on my Hybrid Accord though you can see that there is some variation in numbers.
As I had mentioned in my previous post, the ScanGauge shows high fuel consumption as the engine warms up. Once fully warmed up, the fuel consumption drops to around .2 to .3 gallons per hour at idle.
-When cylinder inactivation kicks in, the mileage shown by MPG indicator on the ScanGauge tends to jump perhaps 25 to 60 percent.
-When autostop kicks in, fuel consumption drops to 0 GPH (because the gas engine is off)
-As the vehicle slows and the batteries are charging, fuel consumption doesn't drop below .2 GPH and the instantaneous MPG shown is sometimes over 100MPG.
-When accelerating, instantaneous mileage is low (sometimes sub 10MPG).
As the car warms up, some hybrid functionality starts kicking in before other functionality, so there is not exactly any one moment when the car "goes hybrid". When hybrid functionality kicks in, whatever guages you have displayed on the ScanGauges still display. There is no little message that pops up or anything saying that the car has gone into hybrid mode.
My typical mileage is just 6 miles to and from work, though I did take it for a longer highway drive last weekend. According to the instrument panel, I drove a round trip of 82.0 miles at 35.2 MPG. According to the ScanGuage, I drove 80 miles at 36.2 MPG and burned 2.2 gallons of fuel.
So the ScanGuage and the Accord Hybrid's instrument panel were fairly close, though not exactly matching. This was a highway drive to a shopping mall and I had to spend 15-20 minutes driving slowly around the mall parking lot to find a place to park which lowered my mileage somewhat.
I have a StreetPilot 2610 GPS in the car so I'm planning on seeing the trip distance it records when I get a chance for comparison purposes, since the GPS is highly accurate. Last weekend I had the GPS and the ScanGauge both on the dash and my recollection is that I was getting speed readings along the lines of the following on the highway:
GPS: 60.0 MPH
Accord Hybrid's Analog Speedometer: ~59-60 MPH
ScanGuage: ~58 mph
Thus far, my experience has been that the ScanGauge seems to be fairly accurate on my Hybrid Accord though you can see that there is some variation in numbers.
Last edited by mikemc; 03-26-2005 at 06:17 PM.
#30
03-26-2005, 06:27 PM
Wanda,
Basically the ScanGauge is a little box that folks can buy for their cars to display information from the on board computer that is built into all cars in recent years. It can show things like how much fuel your car is burning and so forth. It can also provide error codes to you when your check engine light comes on to give you an idea of what might be wrong.
See the following link for info on the ScanGauge:
http://www.scangauge.com/
Basically the ScanGauge is a little box that folks can buy for their cars to display information from the on board computer that is built into all cars in recent years. It can show things like how much fuel your car is burning and so forth. It can also provide error codes to you when your check engine light comes on to give you an idea of what might be wrong.
See the following link for info on the ScanGauge:
http://www.scangauge.com/
