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Speed v. Range - analysis using ABRP

smokie

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Location
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There is frequently discussion here on ekeing out range at the expense of speed. Over a long mainly motorway journey I wondered how much difference it would make.

As it's impossible to do the same journey twice in identical conditions, I plotted a route from my home town to Edinburgh using everyones favourite planning guide, ABRP, varying only the speed parameter. The table below shows the result.

For each speed the Departure SoC assumption was 90% and I didn't have live traffic turned on, or any of the other features which could impact the outcome.

So the time isn't massively different - 20 minutes quicker at 75mph v. 65mph, but you could easily lose that advantage in a minor traffic jam.

I think 75mph uses roughly 16% more charge than 65mph. Which on the new fangled Tesla chargers would equate to about £6 extra, if my sums are right. on the same assumption the whole journey would be about £54 at 65 mph and £60 at 75mph. (Yes there are savings to be made, eg. start at 100%, charge at cheaper places, but this is really a comparison of speed v. range rather than a costing exercise).

Someone has posted elsewhere that 65mph is can be a somewhat awkward speed on the motorways, my own view is simply that I like to feel I am "making more progress" than it feels like I'm making at 65 mph.

I realise this isn't scientific and that folks will find plenty of flaws in the logic but it's the only way I could think of comparing. I guess also a different route may give a different outcome but I'm not that familiar with ABRP and I couldn't find the settings data to reset the mileage if the departure point wasn't my current location (though admittedly I didn't try too hard!!). Obviously non-motorway routes don't have the same scope for varying your speed, nor would they often enable fairly constant maintenance of a speed.

Anyway, here it is, enjoy!! :)


Wokingham to Edinburgh
Assumes 90% at departure
65mph70mph75mph
Mileage398400400
Door to door inc charge time8h 8m7h 47m7h 48m
Charging time1h 3m1h 15m1h 15m
Driving time7h 4m6h 32m6h 32m
Stop 1 miles104110110
Stop 1 % charging32 - 6522 - 6922- 69
Stop 2 miles959292
Stop 2 % charging10 - 7510 - 8110 - 82
Stop 3 miles112112112
Stop 3 % charging10 - 5810 - 6010 - 61
Miles to Destination878787
Remaining % charge101011
 
Thanks for this, very interesting.

I've just done something similar for a 100 mile one way journey I often take along the M4, most of which is 70 with the odd bit of 50.

I lost 5% SOC over the 100 miles doing 70mph instead of 65mph at 20deg.

I lost 15% SOC over the 100 miles doing 70mph instead of 65mph at 5deg - approx. 7% is temperature losses when doing a direct comparison.

As you say not scientific but if true proves temperature has more of an impact than speed, but added together (colder temp + higher speed) can have a more drastic effect on range.
 
Temperature - that's a very good point. I guess I should diarise to revisit this thread in December and see what difference it makes.
 
Temperature - that's a very good point. I guess I should diarise to revisit this thread in December and see what difference it makes.
You can change the outside temp in ABRP - your can even set the vehicle cabin temp. It's just a guestimate but better than making it up ourselves 😂👍🏻
 
You can change the outside temp in ABRP - your can even set the vehicle cabin temp. It's just a guestimate but better than making it up ourselves 😂👍🏻
Agreed, let someone else make it up. :ROFLMAO:
 
There is frequently discussion here on ekeing out range at the expense of speed. Over a long mainly motorway journey I wondered how much difference it would make.

As it's impossible to do the same journey twice in identical conditions, I plotted a route from my home town to Edinburgh using everyones favourite planning guide, ABRP, varying only the speed parameter. The table below shows the result.
I'm afraid to say that ABRP is NOT my favourite planning guide/tool. It's range for the MG5 seems to make no sense to me when I have tried to plan journeys. This can be seen in a recent post where it predicted a SOC fall from 100% to 19% after travelling just 124 miles, this for a LR.
Clicking link below will take direct to the post #23 within the thread.

 
I'm afraid to say that ABRP is NOT my favourite planning guide/tool. It's range for the MG5 seems to make no sense to me when I have tried to plan journeys. This can be seen in a recent post where it predicted a SOC fall from 100% to 19% after travelling just 124 miles, this for a LR.
Clicking link below will take direct to the post #23 within the thread.

Yeah - I think ZapMap is better in so many respects but now that ABRP slowly calibrating to my driving based on OBD readings, I'm hoping to see more accuracy when using with realtime data soon.

Speaking of differences in efficiency at various speed/temperatures, this ZS owning YouTube channel (not sure if the dude is a member here, most likely) seems to log every charging stop for every journey and uses it to predict future journeys at a given temperature / weather conditions. You've got to like numbers to appreciate their fastidious nature though 😀

 
Haha well this exercise was the first time I'd used ABRP. I had the impression people here liked it but it didn't grab me when I first loaded it.

As I've previously said, I rarely have to charge away from home anyway but I do have a trip to Edinburgh in August and as a bit surprised how short some of the legs were, Also I think I want to arrive with more than 10% left.
 
Haha well this exercise was the first time I'd used ABRP. I had the impression people here liked it but it didn't grab me when I first loaded it.

As I've previously said, I rarely have to charge away from home anyway but I do have a trip to Edinburgh in August and as a bit surprised how short some of the legs were, Also I think I want to arrive with more than 10% left.
It's not very intuitive - but there are sliders for longer legs / more stops as well as setting a value for desired SOC per leg. I usually set max charge to 83% and arrival SOC at 20%. It's fine once used to it but overall design doesn't feel well thought out.

DCE95E67-40B9-44B5-BA56-EB8855EA8C2A.png
 
I guess I was a bit lazy in not spending time familiarising myself with the app a bit :) more, and maybe I'll do the exercise again with some more tweaking - but essentially I think it has given me some idea of the impact of speed on economy, which was what I'd hoped to achieve.

As I mentioned, on a long journey it'd be better for my mind to be travelling at up to 75mph than 65 especially if the cost is not more than £6 extra and even though the arrival times would be similar.
 
All these calculations puzzle me. When I eventually get my car I will just drive it until it gets to 20% then top up. All the fluffing about will only give you what 10 miles extra? Nobody did all these calculations with ice cars just worked out the MPG once and that was it until you got a new car
 
I guess I was a bit lazy in not spending time familiarising myself with the app a bit :) more, and maybe I'll do the exercise again with some more tweaking - but essentially I think it has given me some idea of the impact of speed on economy, which was what I'd hoped to achieve.

As I mentioned, on a long journey it'd be better for my mind to be travelling at up to 75mph than 65 especially if the cost is not more than £6 extra and even though the arrival times would be similar.
You've not factored in the cost of the speeding fine 🤣

In all seriousness though, it's interesting to see how every 5mph or 10mph impacts range. I see some people will slow down in situations where charger availability isn't great to gain the required range, so knowing the impact allows an informed decision 👍
 
All these calculations puzzle me. When I eventually get my car I will just drive it until it gets to 20% then top up. All the fluffing about will only give you what 10 miles extra? Nobody did all these calculations with ice cars just worked out the MPG once and that was it until you got a new car
There isn't a problem doing that, more so now where more and more motorway charging hubs are appearing. When there are as many EV chargers as there are petrol pumps or every EV has huge sustained charge rates, these conversations will seem incredibly antiquated.

It's only an issue when you turn up with 20% SOC and 5 cars are queuing for one DC unit due to another being broken or unavailable and you're then having to figure out where the next location you can reach with the range you have. Then knowing that 55mph will give you 20% more range than 75mph becomes a factor.

In general though, I drive until I see a cost-free unit and then plug in.
 
Ha yes! Is there an option in ABRP for speeding fines?

Also if a journey was likely to be in range at 65mph but less so at faster speeds I guess I'd it mean the difference between stopping and not stopping on a journey I would be happy to do the 65mph thing.

I'm not sure it's 20% extra Biffo, but I get your point - if you look at stop 2 at 75mph you have used 59 units to do 92 miles. That's 1.56 miles per unit. In the same stage at 65mph you've used 55 units, so 1.67 miles per unit. So about 7% more.

It's all very rough though, and depends how heavy your foot is to reach your desired speed, and what KERS setting, how many passengers, roof racks, weather, traffic etc etc etc.
 
I seem to remember that the optimal speed for fuel efficiency for an ICE car was on average 56mph with consumption increasing surprisingly rapidly once over. I have not seen similar for EV's, does anyone have info on this?
 
The ICE figure may have a different basis behind it, ICE get less efficient if the engine speed is too low. But all objects suffer from more frictional losses the faster they go, so whilst EV motors are marginally more efficient at certain speeds it is totally outweighed by the higher frictional losses, hence for an EV the slower the better. There's the small matters of the realities of wanting to get to your destination and the effect on other road users.
 
Temperature - that's a very good point. I guess I should diarise to revisit this thread in December and see what difference it makes.

My real world findings, standard range and all affected by driving style/speed.
Winter temp at 0c range = 150 miles
Winter at 5-8c range climbs to 170
Summer at ~12c range 220 plus
Summer temp 17c range up to 270 miles (average speed 40mph stuck in traffic for a long time)
 
I seem to remember that the optimal speed for fuel efficiency for an ICE car was on average 56mph with consumption increasing surprisingly rapidly once over. I have not seen similar for EV's, does anyone have info on this?
Yes I became a fifty sixer during my petrol and laterally diesel days - it just seemed right - the cars were (and are) less stressed and required less in the way of brakes etc as well as giving seriously good economy. Now I venture by voltage with relaxation and regeneration and I still use the 50 to 55 speed and find it suits best for my style of driving as well as giving most miles per top up.
 
There is frequently discussion here on ekeing out range at the expense of speed. Over a long mainly motorway journey I wondered how much difference it would make.

As it's impossible to do the same journey twice in identical conditions, I plotted a route from my home town to Edinburgh using everyones favourite planning guide, ABRP, varying only the speed parameter. The table below shows the result.

For each speed the Departure SoC assumption was 90% and I didn't have live traffic turned on, or any of the other features which could impact the outcome.

So the time isn't massively different - 20 minutes quicker at 75mph v. 65mph, but you could easily lose that advantage in a minor traffic jam.

I think 75mph uses roughly 16% more charge than 65mph. Which on the new fangled Tesla chargers would equate to about £6 extra, if my sums are right. on the same assumption the whole journey would be about £54 at 65 mph and £60 at 75mph. (Yes there are savings to be made, eg. start at 100%, charge at cheaper places, but this is really a comparison of speed v. range rather than a costing exercise).

Someone has posted elsewhere that 65mph is can be a somewhat awkward speed on the motorways, my own view is simply that I like to feel I am "making more progress" than it feels like I'm making at 65 mph.

I realise this isn't scientific and that folks will find plenty of flaws in the logic but it's the only way I could think of comparing. I guess also a different route may give a different outcome but I'm not that familiar with ABRP and I couldn't find the settings data to reset the mileage if the departure point wasn't my current location (though admittedly I didn't try too hard!!). Obviously non-motorway routes don't have the same scope for varying your speed, nor would they often enable fairly constant maintenance of a speed.

Anyway, here it is, enjoy!! :)


Wokingham to Edinburgh
Assumes 90% at departure
65mph70mph75mph
Mileage398400400
Door to door inc charge time8h 8m7h 47m7h 48m
Charging time1h 3m1h 15m1h 15m
Driving time7h 4m6h 32m6h 32m
Stop 1 miles104110110
Stop 1 % charging32 - 6522 - 6922- 69
Stop 2 miles959292
Stop 2 % charging10 - 7510 - 8110 - 82
Stop 3 miles112112112
Stop 3 % charging10 - 5810 - 6010 - 61
Miles to Destination878787
Remaining % charge101011
Looks like the speed limit is just fine!
 
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