ALL POSTS - GOM - Range Meter - Distance To Empty meter

[climber]

In general, how close do you push the battery to zero when driving? How accurate is the GOM? Any general rules of thumb regarding how close to the end of the charge do you run?

for instance, fully charged my GOM says 86 miles. if you were planning a trip, would you count on 86 miles exactly round trip or would you ensure a buffer just in case? 20 mile buffer? 10? is there a built in buffer?

Thanks much!

Jeff

 

[miimura]

I just had an unusually high mileage day (for me), so I will share the numbers.

I did an extended charge and the GOM showed 110 miles. I reset Trip A and went about my day.
At the end of the day the trip meter said 108 miles and I still had 4 fuel bars left on the gauge and I think the GOM said I had 33 miles. However, now that I think about it, I don't think that's right. Each fuel bar is approximately 2kWh, so I had roughly 8kWh left. At 3.3mi/kWh, my efficiency for that day, it would only go about 26 miles. I'm probably remembering the number wrong. In any case, I was able to travel more than what the GOM said and I made my own buffer by doing the extended charge because I knew it would be a 100 mile day. I could have done the same distance on a standard charge, but doing the extended charge made it so I didn't have to even think about running out.

For trip planning you need to get a feel for the efficiency that you get in your car in various situations then plan accordingly. Also, you should check for charging stations just short of your destination so that you have a backup in case you don't get exactly the range you had planned for. Plugshare.com is a good site to use for this. I have also used the GPS NAV at times, even when I didn't need the driving directions. It shows the miles to destination, so it's a convenient way to check your progress along the way. If you are driving on the freeway and think you will be short on range, you can slow down and it will improve your efficiency. Each 5 miles per hour above 60 mph makes a significant difference.

 

[EVBill]

I'm sure everyone is different, my preference is to not plan on going below 10mi on the GOM. There is no built in buffer that I'm aware of. The GOM is based on the average of your previous driving. So the more consistent you are in your driving the more accurate the GOM will be. If your planning a trip that will cut it close on your range you should consider what your planned driving is compare to your norm. Higher average speed in general will be less range than the GOM says, lower average speed will give you more range than the GOM. More people in the car than normal will be less range. Use of fan and A/C deducts about 5% range. Use of defroster on cold mornings deducts roughly 10% range on the GOM. Best thing to do is simply get familiar with your driving habits and what affects they have on range, and if you are going to cut it close on a trip be familiar with charging stations on your route in case you use more range than expected.

 

[bruin nut]

I too had a long drive the other day. On the way back home, I had a chance to do some opportunity charging while having lunch. My drive back home was 81 miles, and the GOM had a range of 85 miles. Most of my trip was on the freeway, and my speeds ranged from stop-and-go to 72 mph. I'd say may average speed was around 50 mph. By the time I pulled into my driveway, I had 19 miles left on the GOM. That's good. I'd rather have a GOM that underestimates than the other way around.

 

[Sun2Drive]

In my experience, the GOM is on the conservative side, so I get more miles out of a charge than the GOM says at the start of my trip. However, if you change your driving habits change abruptly (e.g., your spouse drives for the day with a lead foot and the heater cranked up more than you do normally), then the GOM could very well fall short.

As others have posted, you can adjust your driving and make up the difference though (e.g., drive slower). There are two tricks I've learned to figure out how much to adjust my driving:
1. Use the navigator to see how many miles you have to go and compare it to the GOM miles, and adjust accordingly.
2. Monitor if you're using GOM miles faster or slower than your actual driving. The way I do this is to take the last digit from adding up the last digit of the GOM and the last digit of the odometer every few minutes and see the trend. For example: GOM is x5 and odometer is xxx2 (last digit of total is 7), a few minutes later GOM is x2 and odometer is xxx4 (last digit of total is 6), and a few minutes later the GOM is x9 and the odometer is xxx6 (last digit of total is 5). In this example, you've 'lost' 2 miles of range over the course of these readings (from 7 to 5) because your GOM is dropping faster than you're clocking miles on the odometer.

 

[mark_rivers19]

The Guess O Meter ( GOM) is very conservative.
Last thursday, it was a cold morning and i started with a FULL normal charge with 81 on the GOM.
driving around LA, mostly freeway 405 and 5 with moderate traffic.
"Using the carpool lane ( thanks white sticker!) and cruise control and doing 65-75mph when possible.
i drive the RAV4EV the same way i drive my other ICE cars, so nothing special here.

at the end of the day i did a 79 mile commute ( trip A always starts at 0)
and i have 19 miles on my GOM.

 

[rav4buyer]

Ultimately it all depends on how you are driving relative to your previous trip. If you are driving faster, you will have less mileage than GOM shows, if you are driving slower, you will have more mileage than GOM. The closer the GOM gets to the zero, however, the more accurate it will get. It is just applying a mileage per KWH, but if the KWH keeps getting closer to zero the mileage will obviously reduce as well in proportion. You will never have 15 miles left when you are on LO at highway speeds.

What I normally do to make sure I have enough battery to get home, is check my mile distance to home on my Nav vs. the GOM. I normally give myself about a 1-3 mile buffer between the two. I always check it the closer I get to home as the GOM gets more accurate to make sure I keep that buffer. If I don't for some reason, I will slow down until I get it again. This is a pretty fool proof way of making sure you get home. If you have a one to two mile buffer you will always have enough juice to get home even if you make wrong turn.

 

[Dsinned]

A few other driving activities can also contribute to the "buffer" . . .

1. If it is daylight, turn off your DRLs.
2. Unless you are using your NAV, turn off the Infotainment system.
3. Use "B" as much as possible instead of manual braking.

You can also do a simple "brain teaser" by multiplying the value for your driving efficiency average, times the remaining no. of lit GoM bar segments, times 2. For example, say your indicated average efficiency is 3.0mi/kWh and you have 2 bars left. 3 x 2 x 2 = 12, so you should have a minimum of 12 miles range remaining. If your average is only 2.5mi/kWh, then you would have 2.5 x 2 x 2, or 10 miles range remaining. Cross check the GoM with the results of your arithmetic each time. They should agree fairly closely, but if not, go with the lower of the two just to be conservative. After you get down to one bar, I believe the GoM no longer display your range, but displays a warning message instead. At this point, you still should have a few more miles of range remaining. Try not to miss when that second to last bar extinquishes, and note your mileage right then. Do the calculation one last time, and do not exceed that no. of miles or risk running out of charge!

 

[climber]

This is superb information thanks to all, extremely helpful.

 

[fooljoe]

I completely ignore the GOM, as there's no way to map its prediction to a known miles/kwh figure. Refer to Tony's range chart for a realistic mapping of the bars you see to range with a given efficiency/speed, and/or use the range estimator in RavCharge to predict your range at a given efficiency for your current state of charge.

 

[n3ckf]

I was very unsure of the GOM when i go my Rav4EV 6 months ago. What i did was i kept a log. Since i drive a lot of the same places, this is very useful. So i know what the "GOM range" it takes to go from my house to work for instance, and it varies between 13 and 17. (based on what my *previous* driving was) etc.

For longer drives or unusual drives (driving over Carson Pass to SOuth Lake Tahoe from my house in the mountains) i will calculate it both ways (what i think the GOM will say and using Tony's range chart).

The most accurate way i've found is:
- calculate the actual range to the target using Google Maps. THis will give you distance-on-ground correctly.
- add offsets for any really big hill climbs and for the *diffference* in elevation between your start and target. (using Tony's chart and the average miles/kwh from your car (or use 3.5 if you dont know).

That will give you an actual number of miles of range "needed".

Then when you're driving it, notice the difference betwen GOM range and GPS range on your Nav. I keep that distance in my head while driving. You will see it go down when you're going uphill and up when you're going downhill. For instance when i drove over Carson Pass, i had a differnce of about 26 miles (positive) when i left my house at 3300' but it was down to about 6 miles when i got to the pass (8000'). By the time i got to Lake Tahoe, the difference was back up to 28 miles (because going downhill is pretty free and Lake Tahoe is 2000' below Carson Pass).

This trip was particularly worrying because there are NO public charging locations anywhere other than at the ends. But it turns out it was easy. The overall distance was easy, its just the mountain being in the way that made it a bit scary so i did all those calcs...

 

[mark_rivers19]

I completely ignore the GOM, as there's no way to map its prediction to a known miles/kwh figure. Refer to Tony's range chart for a realistic mapping of the bars you see to range with a given efficiency/speed, and/or use the range estimator in RavCharge to predict your range at a given efficiency for your current state of charge.

i completely agree!
a drive from my house to downtown LA is 28 miles one way.
Normally , you multiply it by 2 and that's it.

However, from house to LA downtown with a trip meter 28-30 miles, i'm consuming 20 miles on the GOM ( maybe it's the flat road)
Going back from LA to house with a trip meter 28-30 miles as well, i'm consuming 35 miles on the GOM.

 

[cossie1600]

I noticed the car is only showing about 82 miles on the range after a full 80% charge. I normally get 92. I assume this is from the lower temperature we have here in the bay area? Or is my car not charging to 80%?

thanks

 

[mark_rivers19]

I noticed the car is only showing about 82 miles on the range after a full 80% charge. I normally get 92. I assume this is from the lower temperature we have here in the bay area? Or is my car not charging to 80%?

thanks

You're fine, always reset your trip A meter.
That's more reliable info.
your current GOM is based on how you were driving the last few days.
You could have been doing less than 2mile/kw that's why it's showing only 82.

it's probably the the hilly situation in your area

 

[fooljoe]

I noticed the car is only showing about 82 miles on the range after a full 80% charge. I normally get 92. I assume this is from the lower temperature we have here in the bay area? Or is my car not charging to 80%?

Could be the temperature, could be your recent driving, probably not anything different about how your car charged. The short answer is nobody knows for sure! That's why it's called the Guess-o-Meter.

 

[rav4buyer]

Check Ravcharge to see how many KWH you have charged in your battery. If it's 35KWH (or whatever level you have set it to) then you have a full 80% SOC.

 

[mark_rivers19]

Left the house yesterday with 84. ( Full standard charge)
came home with a total of 79 miles ( trip A) driven and 19 miles left on the GOM.
No charging in between.

 

[mikegerard]

The GOM is extremely conservative when heat is used.

Last week it was about 45 degrees here. GOM at normal charge showed 66 (my normal "normal" is around 100 - 110). I drove about 72 miles with heat on and normal conditions (mostly highway at 65). At the end of the day I had 18 left on the GOM.

I guess too conservative is better then telling you that you can get somewhere when you can't. But I think I'm going to just start ignoring it in the winter.

Mike

 

[mark_rivers19]

Some additional observations:

After 2 weeks of carefully logging my miles driven, and i tried to keep my normal/ usual route here in LA county ( which includes a drive at the grapevine LA/Kern county line) and the crazy 405/5/10/210 experience.

1.Based on my trip A meter, i can do 100 miles easy on a normal charge regardless of what the GOM post. My lowest GOM full normal charge is 81 and my highest is 103.

2. I always charge at night whether i have 80 or 18 on my GOM.
Having said that,i have noticed that charging with more than 50 on the GOM Usually gives me the lower "full charge" reading ( 81,83,85 and 86).
Charging with less than 20 ( yellow fuel light is ON) gives me the higher reading on the GOM
( 99, 101,105 , 110).


I'm on a TOU-EV plan with SCE so all charging times were made after 12AM.
Temperature at those hours are between 45-55 F.

 

[Dianne]

I agree. Using your trip meter, and paying attention to the RANGE mileage but not taking it too seriously is the key.
IN any given second or minute or freeway or whatever's in front of you, the car has no way to know what's next in your behavior so it's using your last few trips as an average. Mine fluctuates wildly. I can often go 111-117 miles on a single charge even though I often started out with a 96-100 average onscreen when I first unplug. That's w/o using the extended range. That said, when I am in a hurry and can drive 80+ etc, I can also knock that waaaaaay down to 80 pretty D-quick!

The game I play often is this: I set the trip meter to 0 at the start of my travels and remember where I started. It's often off by at least 10% and I try to work it up to being wrong by 15% or even 20%.

I bought my car on August 1, and didn't start driving it regularly till the 5th. It was down for a minor rear bumper repair for 3 days. I already have 8,000 miles on 'er and while I am not as experienced with this technological analysis as many of you smart guys/gals for certain, my personal experience is to just assume I can get 115 miles on a full charge (regular, not extended) when I behave myself and don't drive fast (75+) or accelerate wildly... and coast as much as I can.

Dianne