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Discussion Starter · #1 ·
I'm sure someone out there has tried to dial in the stats. I'm always in eco mode, but I'm open to hearing what you've found to be true in any mode. On a flat surface and a constant velocity, what MPH gives the best fuel economy? or is it battery economy, IDK.....


Thoughts? Experiments? Data?
 

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2019 NIRO PHEV EX
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There are many variables in mpg as you I'll sure already know. You mention terrain- outside temp (time of year), driving conditions, driving style etc can affect mpg.

Speaking for myself a speed of 35 to 45 miles an hour with a slow steady conservative driving style - anticipating stops and letting it coast to a stop or applying gentle brake pressure and then accelerating in a controlled conservative manner are more important than speed.

I live in an area with mostly nice people and this style of driving is acceptable and doesn't cause problems as long as there are two lanes on your side of the road. Also Speed Limit is 25 mph in residential areas 45 to 55 on semi rural roads and mostly 65 on the interstate. There is no reason for hurried driving in our area unless you are in some sort of race to go from red light to red light.

We own a 2019 Niro PHEV EX model. On expressways I use the Smart Cruise Control and also use it on the rural roads with 45 to 55 mph speed limits.
 

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Discussion Starter · #3 ·
I understand some of the variables. But let's control all of them.

Let's assume that the vehicle has been maintained, tires are inflated properly, normal tread, newly paved road, zero wind, flat road, battery at 80% and warmed up, 70°F, and consistent speed.

Given the scenario and you can drive it any speed to go the furthest, what speed will do that?
 

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For a car with an ICE, it will be the slowest speed that you can engage the top gear and not be lugging the engine. For most cars, that's going to be in the range of 40-45 MPH.

For a BEV, there is of course no transmission (except for the Taycan), so no need to get it into the highest gear. Now you are looking at what is most efficient setting. This will depend on the aerodynamic drag of the car, it's mechanical configuration (gear ratios used), and efficiency of the control electronics. But in the end, you'll likely find with a BEV the most efficient speed will be slower than for an ICE powered car. Since the electric motor has full torque from zero RPM, it doesn't need to rev up for power to move the car. The most efficient speed is likely 20 MPH or lower. But who wants to drive that slow? :D
 

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2020 Niro HEV EX+
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I do not have a BEV but I think all the variables that apply to gas engine car will apply to the BEV.
Fuel economy will exponentially decrease (range decrease) because of wind resistance with all other factors being what they are (such as you provided).
For a gas engine, easy acceleration and not exceeding 50mph will probably obtain max results.
I think the same will hold true for the BEV
Your BEV should show max range with city driving where light acceleration and max speeds are 25 - 30mph - added benefit of regenerative braking.
 

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You are probably aware that cold weather will affect a BEV vehicle range by up to 40% but I will mention it just in case you aren't aware of it. If you live in an area that experiences below 0 degree temps do not be surprised by a loss of up to a 1/3 of your normal range. There is nothing wrong with your vehicle when this happens!



 

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Discussion Starter · #8 ·
You are probably aware that cold weather will affect a BEV vehicle range by up to 40% but I will mention it just in case you aren't aware of it. If you live in an area that experiences below 0 degree temps do not be surprised by a loss of up to a 1/3 of your normal range. There is nothing wrong with your vehicle when this happens!
You are probably aware that cold weather will affect a BEV vehicle range by up to 40% but I will mention it just in case you aren't aware of it. If you live in an area that experiences below 0 degree temps do not be surprised by a loss of up to a 1/3 of your normal range. There is nothing wrong with your vehicle when this happens!



That leads me to another thought, but I was hoping to have the previous answer dialed in first.

Whatever the most efficient speed is at a warm temperature, would that be the most efficient speed at a sub zero temp as well?
 

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2018 Niro EX Touring Graphite Edition
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I just bought a 21 Niro EV in September. We also have an 18 Niro EX HEV. I haven't figured out the best speed yet for the EV since around here it's traffic and red lights. I do have about a 20 mile stretch of road that I can squeeze out almost 65mpg in ideal conditions with the HEV. I haven't tried the BEV there yet. I do use the eco+ setting now which switches regen to Level 2. I used to one foot drive it at Level 3 but no more. I've recently went to Level 1 to see if that loosens up the drivetrain a bit more as I feel going from Level 3 to Level 2 seems to and use the paddles as appropriate. Vehicle speed(drag), (HEV) the amount of fuel in the gas tank, wind direction and speed, tire pressure, ambient temperature, duration of your trip, rate of acceleration, rate and duration of deceleration, religiously avoiding coming to a full stop, and in the EV it appears the preset regen setting you've set all affect your miles per kw. Anything over four miles per kw, over five is golden three definitely not so much. Just as in the HEV the trip length plays a role as you can watch the mileage improve as your trip progresses. Much less so in the EV than the HEV but it is there. In September warmth 5+mi/kw city easy, now a chilly November this year and I'm happy to get four.
 
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