Instant MPG dancing

[corncobs]

Question for you all; have you ever seen the instant MPG bar graph "dancing" and jumping like in the video attached.

I noticed ( actually my wife since she is driving) that after the last fill up the instant bar is jumping around like crazy usually it's pretty stable when going a flat stretch of road.

Any ideas? Could it be the gas quality I got? Strangely they only had 86 oct for regular and the station was in the middle of nowhere.

 

http://i1274.photobucket.com/albums/y424/corncobs/E022008E-28C8-42A1-B674-DCC8B82E8317-14836-00000A2EFA7D19C1_zps32023bb2.mp4

 

Not sure if the link works so let's see.

 

None of the links seem to be working for a video only if you sign in to photobucket.

Edited May 6, 2013 by corncobs

[brcd131]

I saw that many times on my 4000 mile trip. Not sure what caused it, but it seemed to come and go so hard to diagnose.

[DeeCee]

I too have seen it on ocassion, usually at highway speeds over 60 mph. Seems to come and go.

[acdii]

Always!

[gadgetguy]

I believe it to be normal when the computer is constantly adjusting based on the load. I notice it more when the car is on a fairly flat stretch of road and it's not accelerating or decelerating hard.

[corncobs]

Jus finished our second day and I hate to say it but i believe its somehow related to the gas I got at this stupid in the middle of nowhere gas station.

We stopped at rest stops in between and the dancing was still there after shutting the car off and back on again. I refilled just before Springfield MO and the dancing is gone / back to normal very slight dancing.

 

I have no explaination why but it seems that my FFH didn't like the 86 oct crap; oh and the FE is better too with the new tank.

[hybridbear]

Question for you all; have you ever seen the instant MPG bar graph "dancing" and jumping like in the video attached.

I noticed ( actually my wife since she is driving) that after the last fill up the instant bar is jumping around like crazy usually it's pretty stable when going a flat stretch of road.

Any ideas? Could it be the gas quality I got? Strangely they only had 86 oct for regular and the station was in the middle of nowhere.

 

http://i1274.photobucket.com/albums/y424/corncobs/E022008E-28C8-42A1-B674-DCC8B82E8317-14836-00000A2EFA7D19C1_zps32023bb2.mp4

 

Not sure if the link works so let's see.

 

None of the links seem to be working for a video only if you sign in to photobucket.

Where was the gas station?

 

Jus finished our second day and I hate to say it but i believe its somehow related to the gas I got at this stupid in the middle of nowhere gas station.

We stopped at rest stops in between and the dancing was still there after shutting the car off and back on again. I refilled just before Springfield MO and the dancing is gone / back to normal very slight dancing.

 

I have no explaination why but it seems that my FFH didn't like the 86 oct crap; oh and the FE is better too with the new tank.

We saw this too once on our road trip to California in January after filling up somewhere near the Oklahoma, Kansas, Texas borders. The majority of that tank acted like that and our MPGs were lower. Once we got through that tank it went back to normal

[hybridbear]

Fill up # 15 on my Fuelly. Guymon, OK. That MPG was lower than expected. The final leg from Kansas City back to Mpls was much higher. It seems like we got bad gas in Oklahoma

[corncobs]

Took me a while but I found the location.

 

Alanreed Travel Center

13100 Interstate 40, Exit 135

Alanreed, TX 79002

 

It's half way between Amarillo TX and the Oklahoma border. It was an odd place since we couldn't go back on the interstate where we exited.

[hybridbear]

That's not too far from where we saw the same thing. We got off I-40 in Tucumcari and started angling north toward Kansas and that's how we ended up in Guymon, OK for gas. I wonder if that part of the country has a different blend or something that caused this.

 

Have any of the Texas owners seen anything like this buying gas in this region?

[Charrua]

I think the gas conspiracy theorists might have it wrong. If the fuel usage were actually going up and down as fast as the indicator shows I think you'd feel it. I could be wrong, but my guess is it's a software glitch in the display.

 

I've seen it 2 or 3 times in the last couple of weeks.

 

Tomorrow we set out on a 2500 mile road trip. I'll try to keep an eye on it and see how often it happens.

[acdii]

Well if the display is jumping it would be difficult to feather, so that could account for the lower returns. In theory.

[corncobs]

I think the gas conspiracy theorists might have it wrong. If the fuel usage were actually going up and down as fast as the indicator shows I think you'd feel it. I could be wrong, but my guess is it's a software glitch in the display.

 

I've seen it 2 or 3 times in the last couple of weeks.

 

Tomorrow we set out on a 2500 mile road trip. I'll try to keep an eye on it and see how often it happens.

Not sure if you were able to see the video but the dancing I saw wasn't just a little bit like I consider normal.

But what I video taped was easily +/- 5 MPG if not more; it was the only time I saw this while on this 5000 miles trip.

Especially odd since ECC was set the 75 MPH and the road mostly flat.

[hybridbear]

When we saw it we also couldn't hear anything to indicate a variation in engine RPM, but the instant MPG was jumping and that tank had significantly worse mileage than expected as can be seen in my Fuelly stats

[Charrua]

Alright. Just got back from what ended up being a 2900 mile road trip. The dancing (about 5 MPG) occurred twice and lasted for a number of hours. Both times the tank was less than 1/2 full when it started . It continued until I refueled, which also means I shut off the ignition.

 

At this point I'm thinking it's random.

[acdii]

If someone else has this, see what happens if you stop and restart and see if it goes away, maybe it is a glitch.

[corncobs]

If someone else has this, see what happens if you stop and restart and see if it goes away, maybe it is a glitch.

Good question acdii; I didn't work for me when I had this problem even multiple on/off cycles it would still do the dancing.

[lolder]

Not sure if you were able to see the video but the dancing I saw wasn't just a little bit like I consider normal.

But what I video taped was easily +/- 5 MPG if not more; it was the only time I saw this while on this 5000 miles trip.

Especially odd since ECC was set the 75 MPH and the road mostly flat.

What your video showed was less than +/- 2 and you probably wouldn't feel that if it is true. You're supposed to use 87 octane minimum and this is what you might expect if the spark advance tried to go where it should and the "knock" detector found out the gas wouldn't handle that much advance. I would think it wouldn't oscillate though. Don't buy octane below 87. If you took it into the dealer and complained, I don't think they'd look at it if they knew 86 octane was used. There was just an item in the press today about refinery problems in the Oklahoma, Midwest area causing a price spike. Could there have been a quality problem? If this doesn't happen regularly, I'd expect it to be a gas problem. The instantaneous fuel economy is seldom steady but it shouldn't oscillate like that.

[corncobs]

@ lolder

Thanks for your response and explanation; I kinda figured it was the gas and yes if I remember correctly it said 86 and since I had never seen this before I didn't think much it. The reaction was still very odd and I wanted to share this expierience.

 

It's a lesson I learned and a mistake I won' make again.

[hybridbear]

Good question acdii; I didn't work for me when I had this problem even multiple on/off cycles it would still do the dancing.

When I first noticed it I stopped and turned off the car and restarted but it made no difference until that tank was gone

 

What your video showed was less than +/- 2 and you probably wouldn't feel that if it is true. You're supposed to use 87 octane minimum and this is what you might expect if the spark advance tried to go where it should and the "knock" detector found out the gas wouldn't handle that much advance. I would think it wouldn't oscillate though. Don't buy octane below 87. If you took it into the dealer and complained, I don't think they'd look at it if they knew 86 octane was used. There was just an item in the press today about refinery problems in the Oklahoma, Midwest area causing a price spike. Could there have been a quality problem? If this doesn't happen regularly, I'd expect it to be a gas problem. The instantaneous fuel economy is seldom steady but it shouldn't oscillate like that.

Interesting, on our trip through the mountains we bought 86 octane a few different times but only this 1 tank had the MPG dancing issue. I wonder if it's just different grades of gas in different states. I feel like the gas where we had the dancing was 87 octane because we were in Oklahoma, not up in the mountains.

[acdii]

Cool, question answered, I like that. When I went to Chino last year in my F150 there were a few times I had no choice but to fill with 85 Octane, where I had been running Premium. There was no noticeable difference in performance, only in fuel economy as it dropped a couple MPG. It did take a few tanks of the good stuff before the MPG returned, and that was weeks after the trip. I went through a MPG challenge with Ford on the F150 because they claimed that it should be getting 18 or so and I was seeing 15 and it had a shudder going up a hill, or from a stop with a load in it. They checked it out and said that I have to run premium in it to get the EPA rated miles. That blew my mind since it states in the manual that 87 is the recommended Octane to use. I challenged them on the shuddering since they had no fix, and they added a 75K warranty to it to appease me.

 

Well, I hate to say it, but they WERE right about the octane. When I used Premium, after the second tank I DID get 18 MPG, exactly like I was supposed to, surprise surprise, a full 2 MPG + difference. After I calculated out the difference in costs, it actually cost a little less to run premium over the long run.

 

I think though it was after this that buyers remorse had kicked in full time on dumping the Flex for the F150. Now I am back to having a Flex, run 89 octane in it, get 21 MPG, and am THRILLED with it. In a stupid sort of way, all things happen for a reason, and I think I was meant to get this Flex after all.

 

So Octane can make a big difference on how a specific car can run, so it is possible that the gas is causing the fluctuations. I didn't put much thought into it, but the timing changes make a load of sense and that can mess with the computer, and at the rate these things happen, makes total sense on why the graph jumps like it does.

[brcd131]

I believe it to be normal when the computer is constantly adjusting based on the load. I notice it more when the car is on a fairly flat stretch of road and it's not accelerating or decelerating hard.

I think this is it. I just had it happen again tonight. I'm currently half way into a tank of gas, I buy gas at the same place every time, and the place is a relatively high volume dealer so I doubt that it is a bad batch of gas. The dancing only happened on an 18 mile trip out, but not on the return. When the dancing happened (which was for most of the 18 mile trip), the battery pack amperage fluctuated wildly, both positively and negatively - faster than the dash could show whether the pack was being charged or discharged. The dancing seemed to be proportional to the MPG - low MPG, little dancing; high MPG, large swings. Speed started out at about 55 MPH, and then slowly increased to 65 where I set the cruise for most of the trip.