Another GOM Lie

[Murse-In-Airy]

Beating this dead horse all the way to decomposition. But the questions keep popping up, so here’s another data point.

Yesterday I had the opportunity to make a little road trip. Total of 412 miles. There’s a free DCFC on the route so no problem.

I left home with 100% SOC and the GOM showing a range of 245 miles on my AWD ER. EPA range rating should be 270 miles at 100%. The horror. My car is broken. I’ve got over 5000 miles on it in 7 months of ownership. How has it not learned how far I can go. This is BS. /s

My first leg to the DCFC was 107 miles and I used 36% battery. Trip meter shows 3.3 miles/kwh. Which calculates out to pretty accurate. 36% of my 88 kwh battery is 31.6 kwh. 107 miles divided by 31.6 gets me 3.38 miles/kwh. Good on Ford. My GOM even went from 245 to 149 miles remaining. So I “Lost” 96 miles of range going 107 miles of actual driving. Reasonably accurate.

But here’s where the fun begins in my little math nerd brain. The GOM shows 149 miles remaining on 64% battery. But if I went 107 miles on 36%, then my 100% GOM should have been 297 miles and at 64% it should show 190 miles remaining. I say this only to drive home the point that the GOM is overly conservative (AKA It LIES). So for everyone still concerned about their GOM… it LIES. My GOM has almost never shown more than 250 miles range even though in the real world, on a 40 degree morning, driving 2 lane county roads at 60 MPH with lots of slow downs for small towns, I should get 297 miles.

But kicked it back up to 80% and continued on my merry way. Further legs show similar results. With a total on that day of averaging 3.52 miles/kwh. Total 412 miles driven, 117 Kwh of electricity used. So with it all said and done, real range for this drive should have been 309 miles. But my car showed 245 at the start of the day. And now, sitting at work, I show 75 miles of range at 36% SOC. That calculates out to 208 miles at 100%.

Oh you silly GOM. When will you learn? Alternately, oh you silly people, when will you stop paying attention to the GOM?

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[Marcel]

Beautiful picture

PS recalculate this part...My GOM even went from 245 to 149 miles remaining. So I “Lost” 106 miles of range going 107 miles of actual driving. Pretty accurate. Or I might think you're lying

 

[Murse-In-Airy]

Beautiful picture

PS recalculate this part...My GOM even went from 245 to 149 miles remaining. So I “Lost” 106 miles of range going 107 miles of actual driving. Pretty accurate. Or I might think you're lying

Thank You, too much multitasking here.

 

[RockwallRick]

I don’t pay that much attention to it, but ours has been showing around 260 miles at 90% charge which seems to be pretty accurate.

 

[JoeDimwit]

Beating this dead horse all the way to decomposition. But the questions keep popping up, so here’s another data point.

Yesterday I had the opportunity to make a little road trip. Total of 412 miles. There’s a free DCFC on the route so no problem.

I left home with 100% SOC and the GOM showing a range of 245 miles on my AWD ER. EPA range rating should be 270 miles at 100%. The horror. My car is broken. I’ve got over 5000 miles on it in 7 months of ownership. How has it not learned how far I can go. This is BS. /s

My first leg to the DCFC was 107 miles and I used 36% battery. Trip meter shows 3.3 miles/kwh. Which calculates out to pretty accurate. 36% of my 88 kwh battery is 31.6 kwh. 107 miles divided by 31.6 gets me 3.38 miles/kwh. Good on Ford. My GOM even went from 245 to 149 miles remaining. So I “Lost” 96 miles of range going 107 miles of actual driving. Reasonably accurate.

But here’s where the fun begins in my little math nerd brain. The GOM shows 149 miles remaining on 64% battery. But if I went 107 miles on 36%, then my 100% GOM should have been 297 miles and at 64% it should show 190 miles remaining. I say this only to drive home the point that the GOM is overly conservative (AKA It LIES). So for everyone still concerned about their GOM… it LIES. My GOM has almost never shown more than 250 miles range even though in the real world, on a 40 degree morning, driving 2 lane county roads at 60 MPH with lots of slow downs for small towns, I should get 297 miles.

But kicked it back up to 80% and continued on my merry way. Further legs show similar results. With a total on that day of averaging 3.52 miles/kwh. Total 412 miles driven, 117 Kwh of electricity used. So with it all said and done, real range for this drive should have been 309 miles. But my car showed 245 at the start of the day. And now, sitting at work, I show 75 miles of range at 36% SOC. That calculates out to 208 miles at 100%.

Oh you silly GOM. When will you learn? Alternately, oh you silly people, when will you stop paying attention to the GOM?

The issue is that we need to trust something. There are too many rounding errors in the system Ford is using. Some days, I can take the car off the charger after it completes charging to 90%, and drive 3-4 miles before it drops to 89%. While on other days, I can let it charge to 90%, take it off the charger after it completes, and it drops to 89% after less than 1 mile (often around 1/4-1/2 mile). So clearly that 90% it charged to has some variance in it.

I don’t worry about my range like I did in March, when this was all still very new to me, but my brain gets grumpy when straightforward math doesn’t work out cleanly. Like I’m almost OCD about that. With the arrival of cooler weather,my brain is itching to understand how the car will react when the ambient temperature is 30°, or 0°, or -15°. Once I have good observed data, I’ll be fine with it.

I do understand that there are too many variables involved for Ford to give us terribly accurate estimates, that’s why I will do my own math so I can see how my variables affect my outcomes.

 

[Murse-In-Airy]

Best news is that in my F-150 at 23 miles per gallon and 3.39 per gallon, this same trip would have cost me just over $60 in gasoline. Instead it cost me $0.00. Thank You EvolveNY.
And in a “REAL” Mustang I wouldn’t have been able to fit all 4 rims in the trunk. So Thank You Ford for making this Mustang a fun car that fit my needs.

 

[JeffGo]

My Audi A4 (ICE) also did not get 485 miles on a tank of premium, which is what its GOM always claimed. So there's that.

 

[DYohn]

It's posts like this that make me give thanks for not suffering from even a trace of OCD.

 

[SEMacheE]

I have never seen over 233 miles at 90% charge on my car. Currently, at 90% it shows just 215 miles. I have 8,400 miles on it in 4 months so plenty of driving for the car to figure things out.. I don't understand how many owners are seeing such high numbers but I can never get to 270. That said, I don't pay much attention to the numbers, I just drive and enjoy.

 

[Murse-In-Airy]

It's posts like this that make me give thanks for not suffering from even a trace of OCD.

Agreed. I wish more people would quit being so uptight about the numbers and enjoy the drive. That’s why I shared.

 

[JamieGeek]

I have never seen over 233 miles at 90% charge on my car. Currently, at 90% it shows just 215 miles. I have 8,400 miles on it in 4 months so plenty of driving for the car to figure things out.. I don't understand how many owners are seeing such high numbers but I can never get to 270. That said, I don't pay much attention to the numbers, I just drive and enjoy.

My CA Rt1 consistently shows 300+ miles on 90% charge.

Over the summer that was fairly accurate as we took it on a few 200 mile trips arriving with around 40% charge remaining. Of course its getting colder here in MI so I doubt I'll be seeing such figures again until Mayish.

 

[Sin_Chase]

The issue is that we need to trust something. There are too many rounding errors in the system Ford is using. Some days, I can take the car off the charger after it completes charging to 90%, and drive 3-4 miles before it drops to 89%. While on other days, I can let it charge to 90%, take it off the charger after it completes, and it drops to 89% after less than 1 mile (often around 1/4-1/2 mile). So clearly that 90% it charged to has some variance in it.

I don’t worry about my range like I did in March, when this was all still very new to me, but my brain gets grumpy when straightforward math doesn’t work out cleanly. Like I’m almost OCD about that. With the arrival of cooler weather,my brain is itching to understand how the car will react when the ambient temperature is 30°, or 0°, or -15°. Once I have good observed data, I’ll be fine with it.

I do understand that there are too many variables involved for Ford to give us terribly accurate estimates, that’s why I will do my own math so I can see how my variables affect my outcomes.

90% SoC display could be anything between 90.0% and 90.9%. So almost almost an entire 1% of variance in actual SoC compared to displayed number.

This isn't unusual!

I'll be applying my motorbike thought process to the mach-e range estimates. That is my motorbikes will show how much fuel is in the tank and its down to me to evaluate what range I have based on my prior experience.

 

[JoeDimwit]

90% SoC display could be anything between 90.0% and 90.9%. So almost almost an entire 1% of variance in actual SoC compared to displayed number.

This isn't unusual!

I'll be applying my motorbike thought process to the mach-e range estimates. That is my motorbikes will show how much fuel is in the tank and its down to me to evaluate what range I have based on my prior experience.

I realize it’s not unusual. I just wish I knew where they change the number displayed.because, then I would be dealing with a potential variance of 1% rather than the potential 2% variance I have now. The method they are using doesn’t matter, I just wish I knew, rather than assumed, what that method is.

 

[Sin_Chase]

I realize it’s not unusual. I just wish I knew where they change the number displayed.because, then I would be dealing with a potential variance of 1% rather than the potential 2% variance I have now. The method they are using doesn’t matter, I just wish I knew, rather than assumed, what that method is.

There are so many variances because that's the nature of SoC.

If I put 50 litres of fuel in a fuel tank I know that's 50 litres in. The float measurements taken can be relatively accurate as it's a physical liquid in a known volume container.

SoC is calculated with far more variables and there has to be some degree of best guessing. It would be interesting to know what method Ford uses for SoC calculation but no matter what it is there will always be some variance, guessing or corrective factors depending on environment and other influences. Its likely why the SoC % does not show decimals, because its pointless!

It's safer if you treat SoC for what it is, an estimation rather than a known value.

 

[HuntingPudel]

I don’t pay attention to the GoM in my Fusion. It lise, horribly, and the wrong way. I know on a hot day it will make about 18 miles. It constantly tells me if will do 26 (the other day it told me 34) when it can only make 16-18. I will treat my MME’s GoM the same way, with complete disdain.

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