triangletom
Active member
TL;DR: Determining the maximum range of the BMW CE-04 is complicated but is fundamentally determined by your average travel speed and the weather.
This data was collected in November and December in North Carolina, and is heavily skewed toward fall and winter weather and long windy country roads (45/55mph). I only included data from rides with enough data to suggest a trend: I chose an arbitrary cut-off of 15km (9.6 mi), meaning I only have 21 rides to include. While I expect the range to improve significantly as it warms up, as of December 27th, here are my numbers:
Best range: 79.9mi (128.6km) at 53'F (12'C) with an adjusted average travel speed* of 38mph (61km/h)
Worst range: 49.5mi (80km) at 41'F (5'C) with an adjusted average travel speed* of 63mph (101km/h)
Lifetime average range: 64.5mi (104km) at 47'F (8'C) with an adjusted average travel speed* of 45mph (72km/h)
* Adjusted Average Travel Speed: My attempt to arrive algorithmically at a number that resembles the typical travelling fast on each road. This drops the first 10% and final 10% of data points to avoid including parking lots and pulling into my neighborhood, and any speeds under 20mph, as these are significantly slower than my local speed limits, and thus reflect deceleration for stops signs and turns. For example, most of the roads for my "worst" example (62mph) had a 65mph speed limit, but some were 45mph and 70mph.
Realistically in North Carolina, you can depend on a range of 75 mi if you are predominantly travelling on city roads or 45mi if you are hugging 70mph highways. My travel is mostly a mix of 35mph/45mph/55mph two-lane roads, which is why I get 65 mi:
There is a huge "down and to the right" trend. You can see it a little more clearly with this graphic:
I have to collect more data toward both speed extremes, but you can see a trend here that your average speed has a huge impact on range. Mode selection does not have as much of an impact on the range as I had initially suspected: if you are using regen to coast to a stop instead of using the brakes, it doesn't matter what mode you've selected, although Dynamic does make me feel like a hooligan on the road.
I did a bit of research on power consumption for speed, and it seems to follow this formula:
power consumption = 0.5 * density_of_air * velocity^3 * drag coefficient * surface area
The power consumption required to overcome wind resistance has a cubic relationship with velocity. You don't notice this as much in an ICE vehicle because it's consuming fuel even when it's not moving. While I haven't seen a drag coefficient number published for the BMW CE04, I'm willing to bet the CE 04 drag coefficient is not stellar.
One thing I've found very surprising is how much weather impacts the maximum range of the BMW CE-04. In a nutshell, my observations so far suggest:
- Rain can result in up to a 10% range reduction
- Freezing temperatures can result in a 33% range reduction (comparing performance between 20'F and 68'F).
Here is what I have so far for range vs temperature:
There is a pretty clear "up and to the right" trend. With more data, I expect this to become more of a curve, with a steeper drop-off appearing near the freezing temperature range, and leveling-off around 70'F. If it helps to see a trend graph, check out this one:
In closing, I feel like most BMW CE 04 owners in the US can safely rely on a range of about 62 miles (100km), unless they live in cities, where they are more likely to see a range of 72 mi (115km). If you are riding in freezing temperatures (which few Americans seem to), cut those numbers by 1/3rd.
You may notice that there isn't a lot of data for rides above 60mph: I don't live near those sorts of roads, and in general don't find >60mph highways to be relaxing. That said, I have one sample so far which included riding up to 71.5mph (115km/h) on I-540. I didn't love the BMW CE 04 in that environment, at least not when compared against a GS. I'm not sure if this is due to the wheel size or the aerodynamics. I still endeavor to collect more data across a wider selection of situations.
For those of you who want to see the raw data and come to your own conclusions: https://docs.google.com/spreadsheets/d/1l68NlBvK7G-YCM0eEJhHALTxE-_L65FxzcsRL3CHbXo/edit#gid=0
I'll post updated graphs once I reach 1000mi (1600km).
This data was collected in November and December in North Carolina, and is heavily skewed toward fall and winter weather and long windy country roads (45/55mph). I only included data from rides with enough data to suggest a trend: I chose an arbitrary cut-off of 15km (9.6 mi), meaning I only have 21 rides to include. While I expect the range to improve significantly as it warms up, as of December 27th, here are my numbers:
Best range: 79.9mi (128.6km) at 53'F (12'C) with an adjusted average travel speed* of 38mph (61km/h)
Worst range: 49.5mi (80km) at 41'F (5'C) with an adjusted average travel speed* of 63mph (101km/h)
Lifetime average range: 64.5mi (104km) at 47'F (8'C) with an adjusted average travel speed* of 45mph (72km/h)
* Adjusted Average Travel Speed: My attempt to arrive algorithmically at a number that resembles the typical travelling fast on each road. This drops the first 10% and final 10% of data points to avoid including parking lots and pulling into my neighborhood, and any speeds under 20mph, as these are significantly slower than my local speed limits, and thus reflect deceleration for stops signs and turns. For example, most of the roads for my "worst" example (62mph) had a 65mph speed limit, but some were 45mph and 70mph.
Realistically in North Carolina, you can depend on a range of 75 mi if you are predominantly travelling on city roads or 45mi if you are hugging 70mph highways. My travel is mostly a mix of 35mph/45mph/55mph two-lane roads, which is why I get 65 mi:
There is a huge "down and to the right" trend. You can see it a little more clearly with this graphic:
I have to collect more data toward both speed extremes, but you can see a trend here that your average speed has a huge impact on range. Mode selection does not have as much of an impact on the range as I had initially suspected: if you are using regen to coast to a stop instead of using the brakes, it doesn't matter what mode you've selected, although Dynamic does make me feel like a hooligan on the road.
I did a bit of research on power consumption for speed, and it seems to follow this formula:
power consumption = 0.5 * density_of_air * velocity^3 * drag coefficient * surface area
The power consumption required to overcome wind resistance has a cubic relationship with velocity. You don't notice this as much in an ICE vehicle because it's consuming fuel even when it's not moving. While I haven't seen a drag coefficient number published for the BMW CE04, I'm willing to bet the CE 04 drag coefficient is not stellar.
One thing I've found very surprising is how much weather impacts the maximum range of the BMW CE-04. In a nutshell, my observations so far suggest:
- Rain can result in up to a 10% range reduction
- Freezing temperatures can result in a 33% range reduction (comparing performance between 20'F and 68'F).
Here is what I have so far for range vs temperature:
There is a pretty clear "up and to the right" trend. With more data, I expect this to become more of a curve, with a steeper drop-off appearing near the freezing temperature range, and leveling-off around 70'F. If it helps to see a trend graph, check out this one:
In closing, I feel like most BMW CE 04 owners in the US can safely rely on a range of about 62 miles (100km), unless they live in cities, where they are more likely to see a range of 72 mi (115km). If you are riding in freezing temperatures (which few Americans seem to), cut those numbers by 1/3rd.
You may notice that there isn't a lot of data for rides above 60mph: I don't live near those sorts of roads, and in general don't find >60mph highways to be relaxing. That said, I have one sample so far which included riding up to 71.5mph (115km/h) on I-540. I didn't love the BMW CE 04 in that environment, at least not when compared against a GS. I'm not sure if this is due to the wheel size or the aerodynamics. I still endeavor to collect more data across a wider selection of situations.
For those of you who want to see the raw data and come to your own conclusions: https://docs.google.com/spreadsheets/d/1l68NlBvK7G-YCM0eEJhHALTxE-_L65FxzcsRL3CHbXo/edit#gid=0
I'll post updated graphs once I reach 1000mi (1600km).
