Doug_G did it well, above. Or perhaps the original message could have said 'the addition of a passenger' instead of 'no offense, but ...'
You have to bring flowers home a lot, don't you?
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Doug_G did it well, above. Or perhaps the original message could have said 'the addition of a passenger' instead of 'no offense, but ...'
You have to bring flowers home a lot, don't you?
Nope, the great thing about my wife is I can be direct (even when it comes off as being an a$$) and she's fine with itOriginally Posted by bonnie1194
..not that I was trying to be one in that post mind you, it could have been a male passenger and I would've posited the same. Thanks for the clarification though Doug, that makes sense.
Never. I tell her I love her every day for putting a down payment on a Tesla.
The world loves to be deceived.
Ahhhh ... smart man.
The truly smart range calculator will interact with the route set on the GPS to figure out the terrain looking forward and predict the SOC at your declared destination. If the answer is negative, the car will suggest strategies, including slowing down and intermediate charging points.
You make an interesting point here !
Above about 60mph, the dominant energy drain on the car will be due to aerodynamic drag. Rolling resistance is usually a constant irrelevant of road speed. A small percentage change in the weight of entire vehicle will have little effect on the energy required to push the car along at a steady speed.
However, you mentioned that there was a strong head wind and rain. A 20 mph headwind will be like driving 15-20mph faster and will increase energy drain.
Rain on the road will effect rolling resistance and reduce the friction/grip of the tyres on the road, BUT there will be a significant amount of energy needed to constantly displace the water on the road as well as all the water going around the treads and being flung off behind the tyre and up into the inner wheel arch.
If there is half an inch of water on the road each tyre will be constantly displacing that weight of water multiplied by the contact patch and vehicle speed. This adds up to considerable amount of energy. I don’t have the equations to hand, but from what I remember seeing in studies on this, rain on the road can increase energy usage by 15 to 20% or more, dependant on speed.
So loosely speaking, head wind and rain combined could dramatically increase your energy drain by 30-40%
I've also seen debates on other weather aspects, such as the marginal effect of absorbing all the energy of large rain droplets hitting the car at speed multiplied by its frontal area, and so on.
From someone who has raced bicycles headwind and rain make a HUGE difference. I just don't know how hard it is to 'measure' these phenomena and adjust rain for it. I mean a dead head wind is a lot different than a slight crosswind. A lot of time the crosswind seems worse. I happen to think it is way to many variables, and stupidly complex fluid flow equations (some of which are NOT SOLVABLE) to get any real calculations out. Maybe a warning notification on the dash "Wind/Rain predicted on route range may be affected." that you can turn on or off.
Knoxville, 110 miles away has many EV events I try and support. On that day I was going to Earth Fair to show the car and the event coordinators went out of their way to ensure I could charge on 110V when I arrived and during the event. But having to drive 220 miles is a bit of a stretch for my Roadster under the best of conditions. We checked the radar and new we would have some rain but we also had a BAD headwind of a good 25mph. While I drive a modest 54mph with the headwind I found my watts/mile was a good 20% higher than before. I really could not slow down as then I would be late to the event. So when I arrived I had used 31 kwh well above my previous two trips of 25.5 kwh. And since I had to get back home that night another 110 miles I was sweating it as I knew the lights would further diminish range and temps in the 40's meant a little heat would be nice especially after sitting in the cool wind all day.
I had a long run with extension cords during the event so rather than charge at 120V I was charging at 105V so I was not charging very fast. We did make it home but with the car saying the battery was so low it could not calculate the remaining range. So the trip and event did little to endear my wife to the car. And I have to agree at 150lbs I have a hard time seeing where that extra weight made much of a difference. And as luck would have it, the winds died down by the time we had to go home so I could not benefit from a tail wind.
Ask any golfer and they will tell you that a strong headwind will significantly reduce distance. Oddly, a tailwind never helps quite as much?
The asymmetry is consistent with physics. Suppose you're driving at 50mph (car or golf ball). With a 20mph wind at your face, the effective speed is 70mph; with the wind at your back, it's 30mph. Since drag forces increase approximately with the square of the speed, that's a lot bigger penalty into the wind than you'll get from the tailwind.
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