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Since aerodynamic drag is the largest force acting against a car at highway speeds, why don't electric cars have an anemometer to tell what the speed is through the air? This would certainly increase the accuracy of range calculations.
A 20mph tailwind would give many extra miles while a 20mph headwind will take away a ton of miles.
A simple wind speed turbine in the grille would probably be enough for the calculations.
I doubt it would improve estimates significantly. If you're driving at a constant speed in the same direction, the estimates based on the energy consumed over the last X seconds would be more than enough to get a good estimate. If you're driving at widely varying speeds and/or directions, the wind speed meter would be useless.
I do think this could help. With my Roadster I frequently drive 110 miles to Knoxville along the same route and average a consistent 235 W/Mile. But one day, a day my wife joined me, there was a strong headwind and rain and I average 285 W/Mile a 20% increase. With the cruise control I can keep the speed constant and there is little traffic along the route so I am convinced it is the weather that made such a difference. We were really sweating making back home. There are no charging stations along the route.
In fact it doesn't provide any more information than what's already available -- the power being consumed at a given speed. If you have a tail wind, it'll be less -- which the computer can see and will factor into its range calculations.
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One thing the car could take into account is the weather. If the car could access a weather database, it could be able to assess the driving conditions and adjust the estimates accordingly. This might be most effective when setting a specific destination on the GPS, because then the car would know how much wind it would receive from which direction and at what speed. It could know the approximate temperature of the road along the entire route. It could know where the road would be wet and where it would be dry. And so on.
I mean no offense to your wife, but could it also have been the extra weight in the car?Originally Posted by dhrivnak
Sooooo many ways to have worded that better ...
Lots of retyping before I posted, but yeah....
Not likely at highway speeds. You might get slightly more rolling resistance, but the mere 90 lbswill be insignificant compared to the 2700 lb vehicle not to mention the much heavier driver (right?). The weight might matter a little bit for acceleration, but at a constant speed it won't matter at all.
At high speeds the aerodynamic drag becomes a really big factor, so I could see how a headwind could significantly affect your range. Even a big crosswind.
Also I've done road trips with my wife in the car, and the spreadsheet still matched our performance very well (slightly conservative in fact).
Next time you see the Wh/mile that high, slow down a little. Your return trip will be a lot less tense.
Please teach us the way....
The world loves to be deceived.
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