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Did my regular trip to my daughters yesterday and thought I'd try an experiment. The journey is 80 miles one way, mainly dual carriageway no queuing in traffic. On the way there with acc on 65mph i got 3.8m/kWh average. On return journey i used acc set at 60mph and got 4.5m/kWh average. I know it's not very scientific but I was very surprised it made that a big difference to the range. It was a bit boring at steady 60mph, but useful to know when I do the journey in winter.
 

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Did my regular trip to my daughters yesterday and thought I'd try an experiment. The journey is 80 miles one way, mainly dual carriageway no queuing in traffic. On the way there with acc on 65mph i got 3.8m/kWh average. On return journey i used acc set at 60mph and got 4.5m/kWh average. I know it's not very scientific but I was very surprised it made that a big difference to the range. It was a bit boring at steady 60mph, but useful to know when I do the journey in winter.

Its not a linear relationship between speed an efficiency... 10% faster or slower doenst mean 10% better or worse. Drag increases massively as you increase speed. Got to just go the speed where you're happiest driving in relation to efficiency. Same also applies to fossil fuel cars ]
 

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Drag=1/2*roe*v-squared. Plus coefficient fudge and frontal area.

So drag is a function of the square of the speed.
 

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Inclines on the route may also have made a difference. Would be interested in the test being done again but in the reverse order, just for comparison. Interesting outcome nevertheless.
 

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I’m on holiday at the moment in the lakes. Our accommodation is at 340m - and the nearest shop (Glenridding) is at about 100. On the way there - I generate enough electricity in the 240m downhill (over 2 miles) to power me the 3 miles along by the lake to the shop :D

it’s a very different story on the way back :D

bit of an extreme story - but lugging 1800kg up even a moderate hill chews up a load of juice.

in my old ICE I used to do Manchester <> Hull many times a year - and often then the prevailing wind direction would make a 5-10% difference.
 

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I'm not crazy, the attack has begun.
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Did my regular trip to my daughters yesterday and thought I'd try an experiment. The journey is 80 miles one way, mainly dual carriageway no queuing in traffic. On the way there with acc on 65mph i got 3.8m/kWh average. On return journey i used acc set at 60mph and got 4.5m/kWh average. I know it's not very scientific but I was very surprised it made that a big difference to the range. It was a bit boring at steady 60mph, but useful to know when I do the journey in winter.
There is +/- 8% variation on any dash reading when one is doing efficiency tests, be it ICE or EVs. So could easily have 'actually' been 4.1% and 4.2% (I'm sure it was better than that but you'll have to do many runs and take some averages).

Nonetheless, yes, take the ratios of the squares of the speeds as the first approximation.

Also, do you know the elevation change? It always figures if the start and end points are different altitudes. I could spot 25m height change over 22 miles on my old commute, but only after several data sets.
 

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You should not care about what the CC is set to, it doesn't matter as much. It matters as much as it has an impact on your average speed.

What you should have observed and if you have a record in the car, you should check, is the average speed for each leg. I know you said that there wasn't much of traffic, but still.

My guess is that the averages will be more closely related to the consumption/efficiency of the car.

(Just as an experiment, my guess is that your 1 leg had an average speed of ~51mph, and your return was at 43mph).
 

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I don't care. I drive with AC, satnav all on, charging my phone, and I love using the ID3 acceleration.
Gotta enjoy it
 

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I have done several trips between Reading and Bristol. Until today I always got more miles heading downhill to Bristol. Today unusually I was driving into quite a head wind so mileage was virtually identical both ways. There are quite a few variables so I have almost stopped worrying about power consumption unless I'm down below 20% charge.
 

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I have done several trips between Reading and Bristol. Until today I always got more miles heading downhill to Bristol. Today unusually I was driving into quite a head wind so mileage was virtually identical both ways. There are quite a few variables so I have almost stopped worrying about power consumption unless I'm down below 20% charge.
Out of interest I looked on a handydandy site for the altitudes of Reading and Bristol. Surprisingly similar over much of the sprawl of each despite Bristol being intuitively on the coast. Both vary between 50m and 90m in height asl over different parts of the two conurbations. So not really downhill overall in either direction.
 

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Out of interest I looked on a handydandy site for the altitudes of Reading and Bristol. Surprisingly similar over much of the sprawl of each despite Bristol being intuitively on the coast. Both vary between 50m and 90m in height asl over different parts of the two conurbations. So not really downhill overall in either direction.
I did that too and was surprised, however there are 3 hills going down where I gain a mile and 2 where I gain half a mile, so going back up in theory should make a difference
 

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The classic argument is that in order to get to the top of those five hills in order to grab some regen you must have been climbing over an extended period without noticing too much. And that reversing the same route would cancel out any such gains as well. At least that's the theory. I suppose that in a purely 'physics' way that is correct but perhaps people tend to push harder up a slight incline to maintain speed but up a steeper hill they might ease the car up rather than force no drop in speed. Basically, it's not as easy as at first sight.
 
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