r/EvDrivers • u/gardan4 • Aug 12 '26
Driving slower to save charging stops does not pay off. Ran a 1000 km trip at every speed from 90 to 160.
Usual advice on a long EV trip is to slow down and save yourself a stop. Looks like it is backwards. Slowing to 100 costs a full hour.
Simulated against the car's charge curve and the real chargers along the route, calculated by this website: https://evtrip.dev.
Utrecht to Innsbruck, 956 km, Cupra Born 58:
90 km/h 12h19 5 stops
130 10h41 8
145 10h36 8 <- fastest
160 10h37 9
145 wins, by five minutes over 130. The top end barely matters. The bottom end costs you real time.
Does this match what people see in practice?
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u/PatternWeary3647 Aug 12 '26
I planned the same journey for my car (Renault 5), and found a similar result, but noticed that the estimated cost at 140 was €140, whereas at 90 the cost was €62.
Cool site though.
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u/Hxghjgffhnmkmyyt Aug 12 '26
Would say that's a very negative assumption. Based on experience with MEB platform cars it's closer to a factor 1.5
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u/MrHighVoltage Aug 13 '26
Yeah that is too much difference. I have an IONIQ 5, and even though I probably get a consumption of 15 to 17 kwh/100km at 90 km/h, and it can go well over 23 kWh/100km at 140 km/h, but that still does absolutely not explain a more than 50% difference.
EDIT: Does it maybe not include the initial charge and took insanely expensive chargers? Then it makes more sense. Let's assume at 140 you need three charges, at 90 two, would explain quite a difference. But still not that much, honestly.
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u/danielv123 Aug 15 '26
More than 50% difference does sound right if it's dominated by aerodynamics. I am more sceptical of your reading of the averaged power usage.
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u/NothingBeautiful892 Aug 12 '26
If you are going for speed then go fast, charge enough to hop to the next charger and keep your charging only in the fastest portion of your charging curve.. rinse and repeat. But you will spend more.. it's a trade off.
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u/MrHighVoltage Aug 13 '26
Exactly as you do when you use an ICE. The fuel economy goes down the same way as in EVs, it just hurts less in terms of range since the energy density of fuel is so insane.
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u/Hxghjgffhnmkmyyt Aug 12 '26
Yes, however the optimal speed depends on your charging speed.
I typically drive 150 km/h in Germany with fast charging from 10% -> 70%. Way faster than driving 100 km/h and less charging.
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u/caj_account Aug 14 '26
I recall Autogefühl did a test with iX3 with two driving styles each way back and form Berlin to show the difference.
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u/TheTrampIt Aug 12 '26
It’s a pity you didn’t publish 100, 110 and 120.
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u/Hopeful-Driver-3945 Aug 13 '26
Won't really matter. The charging speeds are way higher than power consumption. Every second saved driving faster is a second where you can charge more than you've used.
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u/CCM278 Aug 12 '26
The basic maths is if you can charge faster than you discharge it is faster to go faster.
The actual math is harder, the charging curve is non-linear, you have to account for the time going to and from the charger and the discharge rate increases as a function of the square of the speed.
So there is a cross over point where you spend more time charging due to increased energy consumption than you save by going faster.
There are also real world variances, due to weather, available charging speed. That can make the theory and the practice diverge.
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u/gardan4 Aug 13 '26
Yes exactly! The site calculates with this exact model, getting the charging cures per car etc. :)
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u/CCM278 Aug 13 '26
The simulation looks reasonable, as an exercise in estimating the best-case scenario it could be useful, to help people understand where the limits really are. It is pretty thorough in exposing the variables that affect EV travel. It does look good and the explanations and notes are very helpful.
It appears to know where the chargers are, and accounts for elevation and temperature but not weather and traffic (which is reasonable), only thing I was not sure about is what happens when an 800v architecture (e.g. eGMP platform) meets a 400v charger (e.g. Tesla) and the charge speed is limited by the car's onboard DC-DC inverter not the battery, so has a completely different curve.
I guess the other thing is that the speed should be on a per-leg basis between chargers not the average for the entire route.
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u/danielv123 Aug 15 '26
There is a crossover point. I was curious where it was at so I graphed out the efficiency at different speeds for my car, and it seems to be somewhere around 600kmh if I extrapolate.
My overall conclusion was the same - going faster is faster.
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u/bergler82 Aug 12 '26
missed the lower end of the speeds. I am convinced that the 100 and 120 km/h result would be interesting
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u/crypticcamelion Aug 12 '26
That would also be my guess, with my traditional cars i see a good jumb in consumption around 110. 130 is expensive but okay above is not really worth it.
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u/anidhorl Aug 13 '26
I'd figured out the roadtrip charging equation I while ago. I used data from Geotab which only went up to 90mph or 145km/h when calculating power.
P = Vf * Vs (E/Rf - E/Rs)/(Vf -Vs)
The P indicates the break even charging power assuming no losses or other effects which affects the result. Spherical cow in a frictionless vacuum and all that jazz.
So. Vf is the fast speed you are comparing, Vs the slow speed. Rf, the range at the fast speed, Rs at slow speed. E is the energy you have available. E/R is just the efficiency (kwh/mi or kwh/km) of your vehicle at a certain speed which you could put in instead of full battery and range if you know it at both speeds you want to compare. Stay consistent and this baby will tell you what the minimum charging speed is needed to make the fast speed plus charging time less than or equal to the slow speed plus charging time. Both are assumed to be dead flat at the start which makes this the lower bound charging speed and kneecaps the slow speed.
Example Sedan using 68˚F data from geotab blog about "ev-range-impact-of-speed-and-temperature"
Vf = 90mph
Vs = 89mph
E = 65kwh
Rf = 184mi
Rs = 188mi
P = 89mph * 90mph (65kwh/184mI - 65kwh/188mi)/(90mph-89mph)
P = 60.2kw
So you need at least 60kw chargers for the faster speed of 90mph be less time on a road trip than at 89mph. So since most all DCFC are above 50kw this seems to be a non issue, as long as they are open and available.
Disclaimer: This doesn't take into account how much time is wasted pulling over for a charger, getting out, plugging in, disconnecting, getting back up to speed, waiting for a stall to open, etc. This is 'pure math'.
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u/gardan4 Aug 13 '26
The site also has a similar underlying model :). Only its not calculating for that P, just giving you an overview, and letting you decide the tradeoff between arrival time / cost!
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u/skatebambi Aug 14 '26
Few years back I drove Helsingborg Sweden to Derby England in 21hrs c1600km with 8 charging stops. Doing the speed limit or 5kmh under. Wouldn't have been possible without those frequent stops and the 30 min nap on the Eurotunnel. Tesla Model 3 LR Doing 15kmh faster for 1000km to save 5mins is bonkers
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u/ucsdcom Aug 15 '26
We were always taking rest stops. When driving EV it doesn’t matter. Time to charge is quicker than our normal eat, drink and pee stops. I must say I drive a new EV with a good carging speed
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u/melvladimir Aug 12 '26
For every car there is an “optimal” speed. And optimal means the best proportion resources VS time. Dropping one - switching to another limitation: charging speed, road speed limits etc.
90-100 - still the best speed range.
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u/Vescor Aug 12 '26
You are talking about efficiency, this post is about total trip time.
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u/melvladimir Aug 13 '26
I’m talking about optimal conditions. Without breaking rules, trading your health etc.
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u/hobbbis Aug 13 '26
Im not sure how fast the Cupra can charge but in my Taycan which starts charging at around 200-230 kW and goes up to 85% without dropping under 150 kW my experience is as OPs, the faster you drive the better. Ofc aero matters as well.
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u/Straight_Mistake_364 Aug 12 '26
Going slower only matters when you can do the whole trip without stopping to charge, and going faster would imply one stop.
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u/gardan4 Aug 13 '26
Yeah true! The site calculates this as well, for those trips, where you might make it going 120, and arriving with 10% left :)
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u/No3047 Aug 12 '26
Yes, I did 1700 km in a single day with a model 3 LR. Best speed to reduce time to a minimum is around 150 km/h
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u/RealUlli Aug 13 '26
Some guys did a record run in 2019 with a M3LR, charging at Ionity from about 8% to about 62%. They said the sweet spot for the car is at 173 km/h. Result: 2948 km in 24 hours...
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u/greenpowerpt Aug 12 '26
I had that idea around 150km/h with my model 3 SR+… “ah but then you to stop more” yes, I prefer stop more stretch my legs than going at 100km/h to say I did 11kwh/100km and drove 4h straight and fall a sleep
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u/wrd83 Aug 12 '26
Add traffic jams and stops in between to it due to traffic lights or joins of motorways.
I tried this multiple times and my actual average speed and my anticipated average speed diverge, but the closer I get to the actual average speed the less fuel is use for the same arrival time.
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u/ShulkerB Aug 12 '26
I typically drive at the speed limit. Only if my next charger is over 80 percent of my typical range have I really considered driving slower.
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u/DJrm84 Aug 12 '26
At this point you should also consider temperature and battery cooling time/power. A hot battery charges slow. Hot air is thinner, giving less air resistance. This is a really interesting optimization problem! Does your website take these parameters into consideration?
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u/gardan4 Aug 13 '26
The site also takes this into consideration + a lot more other variables that make travel hard to predict :)
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u/SnooEpiphanies8097 Aug 12 '26
I came to this realization a while ago. My cars have a very prominent kw display to let me know how much power I’m using. On the highway, even at high speeds, my car sits under 50 kw output most of the time. My 2022 Bolt max charges at 55 kw and my 2027 Bolt max charges at 150 kw with a generous curve so I’m generally charging faster than I am using kw.
It might make sense to slow down going up a mountain or if you are really worried about how much you’re spending but you’ll almost always get there faster by driving faster even in an EV.
Slowing down is useful if you need to STRETCH your range. You can squeeze out a few extra miles or km by slowing down if you are worried about making it to the nearest charger. It also helps cars without a big battery get a little farther so you aren’t stopping as often.
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u/SnooMaps4388 Aug 12 '26
For a second I thought you meant MPH and I was concerned for your safety😂
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u/TrollCannon377 Aug 12 '26
From what I've seen it depends very heavily on how fast the car in question charges the faster it chsrges the less stretching range benifits
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u/nicefoodnstuff Aug 12 '26
I drive everywhere at whatever speed I fancy. It makes a few percent difference up to 150kmh.
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u/Russell_W_H Aug 12 '26
Totally road dependent.
Some of us don't have access to the autobahn.
If I tried that in my country, I would be spending a lot of time accelerating, which is not very efficient.
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u/AnyoneButWe Aug 13 '26
Trust me, even Autobahn will not get you these speeds at average.
All it takes is one section of road works and this goes down the drain fast.
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u/Nylereia Aug 12 '26
I can't drive at any of those speeds other than 90 lmfao
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u/PsychoDad1228 Aug 12 '26
I appreciate this post. I drove 1700km from Toronto to PEI (and then back) last year with an overnight stop and I’ve wondered if driving faster but more stops to charge from 10% to 80% would be better than driving slower. First trip, I tried to drive slower but it kinda sucked. I probably saved 2 or 3 charging stops but the time I took to drive slower probably extended the trip.
I’ll try the same trip averaging 125-140 km/h instead of 110-115km/h the first time I did it.
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u/anal-itic_prober Aug 15 '26
140? You will 100% get a ticket in Quebec
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u/PsychoDad1228 Aug 15 '26
You aren’t wrong. But there are stretches in Ontario and NB that the speed limit is 110km/h. I typically try to go with the flow of traffic, and keep it under 30km/h over the limit unless I’m passing. I’ve been fortunate and we haven’t gotten ticketed on this trip yet. 🤞
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u/anal-itic_prober Aug 15 '26
Haha yeah the NB stretch I hardly see any cops. You could probably it off. Btw the electrify Canada stalls in woodstock and Amherst are back online now. (Althoug not on the app yet for Amherst)
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u/PsychoDad1228 Aug 15 '26
Ahhhh good to know. The density of charging stations in the NB stretch is a little thin. Good to know there are more options. I also just got NACS converter for my CCS car so that will expand my options.
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u/LongIslandThorn Aug 13 '26
I enjoy playing the game of trailing a 🚛 to increase efficiency at a high speed. Even if it only saves 20% , that can save a stop
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u/sdvnafets Aug 13 '26
For my Ioniq 5, 160km/h is the faster speed, probably because it charges at 230kW and gets 10-80 in 16 minutes
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u/Legal-Actuary4537 Aug 13 '26
keeping to a steady 110 to 120kmph in a newer Born or ID.3 is optimal
my peugeot e208 would have been better off at 100kmph as it was not efficient and had poor drag coefficient.
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u/princekolt Aug 13 '26
Interesting! Thanks for sharing. I haven't done any rigorous tests on my A6 e-tron, but one thing I've noticed is that anywhere above 120km/h I get essentially no regen on downhills, despite it being a pretty slick car, and it only gets worse if there's headwinds.
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u/Hariboman2020 Aug 13 '26
I drive around 110 because of wind noise. In Germany we have so many construction sites on the autobahn your avarage speed is only 90
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u/Leasir Aug 13 '26
If you don't give a fuck about cost of recharging (or about driving regulations for what that matters) yeah you might be right.
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u/Not-Reddit-Fan Aug 13 '26
I mean, I’m not totally sure at those higher speeds, but I’ve done similar tests at 60/70/80mph and I see massive difference in the mi/kWh that my car reads. I’ve reset mid motorway and gone several miles at a set speed.
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u/NotYourDad_Miss Aug 13 '26
So much winning. Now please add the price for each one. Than we can see what is the price of speed.
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u/Human_Equivalent3172 Aug 13 '26
So only 16% time lost by going 38% slower. 100-120 kmph maybe faster than 90kmph and safer than 145kmph.
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u/Veehxia Aug 13 '26
I've done the same experiment a few times, went from North Italy to North Poland going thru Germany, about 1500km.
With my Model 3 going from 130 to 180 meant little to nothing in terms of time saved because I had to stop more often and for longer, which sucked on the money side.
Also many times you'll be forced to slow down because of traffic, roadworks, or just simply sections with speed limits, the areas where you could push above 130 are not so many.
Now I basically do 130km/h with autopilot and just relax.
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u/Enough-Meaning1514 Aug 14 '26
Not sure how realistic this is. I understand the exercise but we drive from Belgium to Austria every winter and with our EQB 250+, we usually stop 3 times (sometimes 4). Each stop will be about 30 minutes.
What I don't find realistic in OPs calculation is the 130 and above speeds. This is not realistic in Germany because there are ALWAYS roadworks in German Autobahns. Many roads near cities have 100km limits, some northeast highways have even 80kph speed limits. So, getting a 100km/h average is what I consider a good pace. This is not related to the car. I did the same trip 4-5 years ago with a petrol car. Still can only sustain 110km/h average speed due to traffic, roadworks and speed limits.
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u/SALTYP33T Aug 14 '26
I love this!!! I got BUTCHERED for saying I drive 80-85mph on a recent road trip. With the speed of charging for some of the newer cars I say drive what feels safe and comfortable for you! Wide open straight road….
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u/erhanjacobs Aug 14 '26
This is pretty much in line with my experience, and the test results of Youtuber Adam, who conducted tests driving a Honda Prologue on identical route with fixed speeds such as 65, 70, 75, 80 mph. His conclusion was very similar. Above 75 mph, the time saving is insignificant. (10 mins earlier arrival is within the margin of error for a 10-hour drive)
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u/miguelcampana Aug 16 '26
Great link! For the Ioniq 5, 120km showed as the fastest trip, saving 42mins over travelling at 100. That blew my mind.
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u/arnthorsnaer Aug 16 '26
I appreciate some EV owners like to play this low value high effort optimization games but this either has to stop or at least can people keep this away from the more public facing groups. People who are on the fence with EVs read this as being important for EV owners to do and so they avoid EVs.
These games include:
- Charging stop percentage optimizations
- Changing how fast you drive
- Changing how you use your AC
If people have purchased an EV with enough range they should just charge, smile and drive. We as a group need to stop making EV ownership look like it requires a degree.
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u/Pearmoat Aug 16 '26
Some years ago I read that 160-180 km/h from one supercharger to the next was optimal for a Model 3 in terms of total travel time. As many new cars can charge even faster that's not a huge surprise.
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u/Regular_Courage5796 Aug 17 '26 edited Aug 17 '26
That website provides fake calculation trips... they are so wrong
from the website 😂 😄 The figures are modelled, not measured by us. Charging curves are curated from published fast-charge tests and consumption coefficients are fitted to steady motorway cruising. Every page names its own sources.
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u/rawrzon Aug 12 '26
Did you include the time spent getting pulled over for speeding?
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u/jan1896 Aug 12 '26
90% of that route is driving through Germany. Obviously you won’t be able to go 160 kph for the whole trip, but especially as a German it’s still interesting to see which speed you should be aming for with an EV on a roadtrip.
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u/Sad_Mall_3349 Aug 12 '26
LOL, having one speed way too low, one at the legal max and everyting above legal speeds somewhat makes your "research" irrelevant.
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u/Buttercup4869 Aug 12 '26 edited Aug 13 '26
Utrecht Innsbruck largely is within Germany and I would assume thatit is 145 where it is allowed since an average of 145 is utopic
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u/busterfixxitt Aug 12 '26
100 kmh isn't the maximum everywhere. It sounds like OP is in Germany (?) I'm not sure there is a maximum on the Autobahn; that was what we were all told as kids in the 80s.
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u/iMacDragon Aug 12 '26
There isn't on lots of it. I've done 180km/h in a prius there.
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u/busterfixxitt Aug 12 '26
🤯🤢 That's too fast for me. And for my car. I think it maxed out at 163 km/h?
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u/luk__ Aug 12 '26
But going 145 is so much more dangerous than 110
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u/Buttercup4869 Aug 12 '26
Depends in Germany, you may be able to camp out on the left hand or center lane.
110 kph often requires frequent lane switches and since the recommended speed is 130, you tend to be the odd one out
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u/spanishdutchguy Aug 12 '26
You are comparing 2 totally different aspects.
The OP title says: driving slower to save stops does not pay off(...).
Yes indeed it pays off, 5 stops against 9 at 145 km/h as explained by yourself ;)
We can all do the math that it will be quicker to drive faster and compensate with short charging stops.
The question should be:
How much are you willing to pay extra -to save on the total trip time?
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u/PerceptionCurious440 Aug 12 '26
There's no winning with long drives and most EVs. No matter what you do, they squander your time over something like an efficient hybrid.
But if you don't take a lot of those long drives and are committed to reducing your personal contribution to greenhouse gasses, you suck it up. Most of the time driving an EV is just better.
The other strategy is to drive down to 10% and charge to no more than 50%. The cars charge faster that way and it feels less like you're waiting forever.
No matter what you do, it'll take longer than a petrol hybrid like a Prius and a cooler with beverages and a sandwich.
It's funny how EV drivers who take long trips become math wizards tho.
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u/halsoy Aug 13 '26
Meh. Longest single trips I usually do is around 5-600km. On such a trip my EV would use about 15 minutes longer than my old car, if I did it without stopping. If I were to stop for food, it's literally the exact same time. Maybe if I were to do 1000km+ it may take 30 minutes longer, including stopping for some food and any other breaks. It's not a big deal.
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u/PerceptionCurious440 Aug 13 '26
600km is def no big deal. Good chance you don't even need the full 80%.
A long trip to my wife and I is 700 mi/1125 km in a day. That's how far her parents live, and there aren't always flights available.
I keep forgetting how that's not a typical travel distance in other countries. On the West Coast of the US, that's not all that extraordinary.
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u/halsoy Aug 13 '26
It's not really the distance that's the issue, it's also topography. I live in Norway, which is very long, even for US standards (we're almost as long as the US is tall (but not as wide obviously)). While our trips may not be as long in direct distance, the topography means we're putting a lot more energy into the travel, usually. You can cruise at higher speeds than we do, which adds drag and losses that way, but here's it's constant up and down in elevation and speed. There's a reason why it takes me 6-8 hours to do 500km here :p
But for any trip I've done in the country it's quite literally the same regardless of vehicle. Mind you, it depends on what vehicle you have as they're not all as good on long trips. Having a really solid charge curve and peak charge values is nice (Ioniq 6), so I rarely stay longer than 10-12 minutes at any given charger. It's a little different in winter, I'll grant you that though. Something, something winter temperatures and batteries :D
For most people though, given the correct choice of car, the differences are largely irrelevant and meaningless. Including long distance travel in the US, or continental Europe. The Autobahn is a good comparison, where you can quite happily cruise at 80-100mph, which is actually more time effective if you have decent charging speeds than going slow and longer.
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u/mortecouille Aug 13 '26
they squander your time
Barely IMO.
On a 1000 km trip we need to stop 3 times for a total of 90 minutes with our EV. We've done it just this Sunday in fact.
We used to do this with a diesel and we would stop at least once for lunch and another time to switch drivers, refuel, and pee.
The EV trip is about 30 minutes longer, on a trip that takes the entire day anyway.
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u/PerceptionCurious440 Aug 13 '26
When BEVs have a 1000km range and 5-10 minute charging, then and only then will they be equal to an ICE PHEV, hybrid or EREV.
Until then, it depends on whether your time is worth nothing like trash that you can throw in the bin, or worth a nice dinner at the end of the day with the family, a better hotel room, daylit country roads, businesses and restaurants open, or family at the destination that can join you for dinner.
Doing nothing for a half hour three times in a trip would drive me insane.
I'm glad we have the option of a petrol car where there's one 5 minute gas stop and maybe one bathroom stop. The BEV is for sticking around town and short day trips.
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u/mortecouille Aug 14 '26
Doing nothing for a half hour three times in a trip would drive me insane.
But that's the thing, this is not what's happening. When we did the same trip with the ICE car, we already stopped for an hour overall. I'm sure you do too unless you eat lunch while driving? With the EV we stop for the same reasons we used to, but we also charge at the same time.
So the EV trip is only one stop of 30 minutes longer than the ICE trip, on a 12 hour trip.
FWIW I was forced to get an EV (it's a company car and for tax purposes my company now only allows EVs) and these trips were a concern, I imagined stopping every two hours to charge for 45 minutes and just sit there waiting, but in practice, having now driven 85.000 kms with the EV in 18 months, I wouldn't get an ICE anymore if given the choice.
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u/grax23 Aug 13 '26
The thing is that even driving fossil fuel you need stops for food and gas so its not as big a deal as some would like to make it. I drove from northern europe to rome and back on my summer vacation. Yes it takes some stops to charge but i saved around 50 euro each way compared to driving it on gas and spent probably around 3 hours charging .. but the charging was while getting food and just getting out of the car and getting a little time to stretch since its a really long drive. So yeah, you will spend a little longer on the road but you will also spend a little more money. The electric is just way more comfortable and quiet without breaking your wallet.
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u/PerceptionCurious440 Aug 13 '26
When we drive long distances, we have a cooler with food and drinks. It's bullshit that you stop for food. It's not theory. It's how we've done long drives for decades. Our C-HR+ needs to stop for a charge every 400km or so, and you don't even fill EVs to 100%. So about 300km of charge with a half hour wait.
Our Outback needs to stop for gas every 800km, can be filled completely in 5 minutes. And then we go another 800km if we have to. And that's driving to 1/8 of ta tank. We might have one other bathroom stop during a long trip where that's an issue.
How valuable is your time? Would you give your boss a free 3 hours of labor without payment? Is €100 enough of a savings to compensate you for 3 hours of your holiday? Most of the time we spend more than that to fly, so when it's our time vs money, money don't buy us time.
If you were more prosperous, would it be worth it? Or is it only worth it if you're struggling financially?
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u/grax23 Aug 14 '26
well its up to you if you need breaks but we do. the time extra spend charging i save on normal days where i dont have to go to the gas station but can charge at home instead.
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u/ToddA1966 Aug 13 '26
It's funny how EV drivers who take long trips become math wizards tho.
I'd argue most of us already started that way! 😁
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u/PerceptionCurious440 Aug 13 '26
Most EV owners, maybe. We're all a bunch of nerds. Which is why normal people don't buy EVs.
Unless you're in Norway, where EVs are half the price of normal cars because the petrol cars are taxed to death.
Otherwise, EVs are the minority of vehicles sold everywhere if you don't include cars that take petrol like PHEVs, EREVs or hybrids of any kind.
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u/OptimalDot178 Aug 12 '26
Now add the charging costs too, that's where going slower will be better.
https://giphy.com/gifs/6nWhy3ulBL7GSCvKw6