Unusually accurate GOM?

[timbop]

Wonder if it depends on how variable your driving is. Here in Phoenix, my GOM will give me 30 extra miles compared to EPA rating in moderate weather which is accurate for me. Then I took the car on a long drive for the first time. It was overestimating the range. On the way back home it was more accurate. Now it's showing me at 330 on a full charge again.

I think it is driving variability. I'm not even convinced it has any kind of learning other than just basic average mi/kWh. But, I've only had it for 2500 miles, and haven't been experimenting enough yet.

This is definitely a significant factor, as is changing weather. I don't have complete examples of what the GOM read, but since I've been working from home most of the time I have 2 kinds of trips: going to pick up takeout, and driving 2+ hours roundtrip on the highway. When doing its calculations the car has no idea which drive I am about to do, and the variable weather doesn't help.

Here's a concrete example of my driving efficiency on exactly the same 160 mile drive on exactly the same highways at the same speed setting on cruise control almost all of the way. Since it is a mix of expressways, residential roads, and state highway with traffic lights the average speed is about 60 mph:

1. Two weekends ago it was gorgeous and sunny with temps in the upper 60's to low 70's. GOM showed around 240 miles on 90% charge for projected 266 miles at 100% and 3 mi/kwh. I actually got 3.5 mi/kwh for a true 100% range of 308. That's a 15% difference.
2. Last weekend it was colder so I left before noon with temps in the mid 40's and it projected around 200 miles at 90% for a range of 222 miles and 2.5 mi/kwh. For the trip down I got 3.1 mi/kwh, so a delta of 24%. I returned that night when temps dropped into the 30's and I did only get 2.5 mi/kwh, but I didn't pay attention to what the GOM read before the return trip so can't say how accurate it was.

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[Murse-In-Airy]

I’m pretty sure my GOM can’t predict my range because my driving is unpredictable. Most days I drive 8 miles to work. Then next day I drive 8 miles back home. Some days I’m happy to set the cruise to 58 MPH. Some days I’m running late and do 80 MPH on the rural road with no traffic at 5 AM. Some days I need to pick a kid up from school, take them to the orthodontist, then return them to school so I do 80 miles that day. Some days my work location gets shifted and without warning I’m driving 240 miles to get to the new site. I’m bluecruising at 65 MPH (no hurry to get there) for 240 miles. Then when I get off work the next day, I’d really like to get back home so it’s 75-80 MPH the whole way, seeing how many people I can safely pass. Add the bipolar tendencies of Mother Nature in Northern NY, and my GOM just has to be about ready to give up on me.

 

[dtbaker61]

There are plenty of examples from forum members with GOM readings that are way off the mark. No question about it. I am just curious how many of us have vehicles with fairly accurate GOM readings most times. ...

I would guess that if your drives are usually a loop from-to home which eliminates one-way elevation changes, and temp approaches 'standard', with speeds approaching 'normal' mix of stop/go and highway.... then the GOM will be spot on.

Its the one-way trips with elevation change, or significant temp changes that seem to freak out the GOM.

One way around this might be if we could adjust the 'trailing average' duration to adjust to current conditions a little tighter. Rather than use your entire History.... what if the GOM used the average consumption over the last 25 or 50 miles to predict remaining range with remaining kWhr.... This would effectively 'sense and adjust' to recent driving conditions a little tighter I think.

 

[timbop]

I would guess that if your drives are usually a loop from-to home which eliminates one-way elevation changes, and temp approaches 'standard', with speeds approaching 'normal' mix of stop/go and highway.... then the GOM will be spot on.

Its the one-way trips with elevation change, or significant temp changes that seem to freak out the GOM.

One way around this might be if we could adjust the 'trailing average' duration to adjust to current conditions a little tighter. Rather than use your entire History.... what if the GOM used the average consumption over the last 25 or 50 miles to predict remaining range with remaining kWhr.... This would effectively 'sense and adjust' to recent driving conditions a little tighter I think.

At least for my example above, we can virtually eliminate altitude changes - my house is roughly 75 feet above sea level and I went to the shore so ended 5 or 10 feet above sea level. altititude does change on the route, but not by a whole lot (varying between 130 feet and 10). Here's the analysis by ABRP:

 

[SnBGC]

Wonder if it depends on how variable your driving is. Here in Phoenix, my GOM will give me 30 extra miles compared to EPA rating in moderate weather which is accurate for me. Then I took the car on a long drive for the first time. It was overestimating the range.

I am sure that has an impact. I think my driving style and habits are fairly consistent day to day.

I would guess that if your drives are usually a loop from-to home which eliminates one-way elevation changes, and temp approaches 'standard', with speeds approaching 'normal' mix of stop/go and highway.... then the GOM will be spot on.

Its the one-way trips with elevation change, or significant temp changes that seem to freak out the GOM.

One way around this might be if we could adjust the 'trailing average' duration to adjust to current conditions a little tighter. Rather than use your entire History.... what if the GOM used the average consumption over the last 25 or 50 miles to predict remaining range with remaining kWhr.... This would effectively 'sense and adjust' to recent driving conditions a little tighter I think.

It is about 21-22 miles to the office. Around 43 miles round trip. The other 100 plus miles traveled in any given day is around the greater Phoenix area. Sometimes just driving from Glendale to Scottsdale to Queen Creek just to see 3 different jobsites is enough to add a ton of miles all by itself. It's crazy how fast the miles add up just by driving around this place. Most of it is freeways....

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