An alternative to shifting in a Tesla...

[lolachampcar]

Yep, pretty sure after reading though your post that you actually agree with me.
Sure, ICE is far far less efficient than BEV but it is the energy density of gas that allows them to be such inefficient pigs along with their ability to sustain very high power levels (low source impedance of the fuel) that lets them fight the big aero loads associated with top speeds.
My post was simply explaining why BEV does so well down low, so poorly at higher speeds (in comparison to ICE) and why gearing does not fundamentally change this

 

[richkae]

Yep, pretty sure after reading though your post that you actually agree with me.
Sure, ICE is far far less efficient than BEV but it is the energy density of gas that allows them to be such inefficient pigs along with their ability to sustain very high power levels (low source impedance of the fuel) that lets them fight the big aero loads associated with top speeds.
My post was simply explaining why BEV does so well down low, so poorly at higher speeds (in comparison to ICE) and why gearing does not fundamentally change this

Re-read my post and pretend my original intention was only this: Any EV can use a lot less horsepower to go the same speed as an ICE car because of less wind resistance. Because of that, we don't have long to wait before high speed, high performance EVs compete.

The EV1 without a speed limiter could hit 180mph with 137hp. It had a 0.19 Cd with a tiny frontal area because it didn't need radiators.

 

[fadkar]

Re-read my post and pretend my original intention was only this: Any EV can use a lot less horsepower to go the same speed as an ICE car because of less wind resistance. Because of that, we don't have long to wait before high speed, high performance EVs compete.

The EV1 without a speed limiter could hit 180mph with 137hp. It had a 0.19 Cd with a tiny frontal area because it didn't need radiators.

Yeah I'm sure lolachampcar agrees with those statements. EVs are simply built more efficiently. He was just saying as of now, gasoline powered cars have an advantage at higher speeds. That may change with improvements in battery technology.

 

[richkae]

Yeah I'm sure lolachampcar agrees with those statements. EVs are simply built more efficiently. He was just saying as of now, gasoline powered cars have an advantage at higher speeds. That may change with improvements in battery technology.

Unfortunately we don't even really know what current EV technology is capable of at high speeds.

The Leaf is governed to 93mph, the Honda Fit governed to 90mph, the BMW i3 governed to 93mph...
Only Tesla makes an EV that is capable of 100+ mph.

I don't think that Tesla has put much effort into high speed performance. Having a quick 0-60 is the easiest thing for an EV, and looking past that is harder and won't gain them a lot more market share.
Even if they did, I think the state of the art would advance much faster if there were multiple players.

It is amazing that it is still a one horse race.

 

[fadkar]

Unfortunately we don't even really know what current EV technology is capable of at high speeds.

The Leaf is governed to 93mph, the Honda Fit governed to 90mph, the BMW i3 governed to 93mph...
Only Tesla makes an EV that is capable of 100+ mph.

I don't think that Tesla has put much effort into high speed performance. Having a quick 0-60 is the easiest thing for an EV, and looking past that is harder and won't gain them a lot more market share.
Even if they did, I think the state of the art would advance much faster if there were multiple players.

It is amazing that it is still a one horse race.

Yeah I'm shocked that Tesla is still pretty much the only player in the game right now. Tesla is way ahead of the game because of the supercharging infrastructure that theyve been building so rapidly. It isn't enough to just make a good car that runs on pure electricity (which no one besides Tesla does), but it is absolutely necessary to support that car with a viable infrastructure.

Like jdbob had mentioned, there are now Formula 1 type racing for EV race cars so there definitely does seem to be some interest in high speed performance. But even those cars hit a top speed of around 140mph... And I'm not sure that just sticking a 200kwh battery in a car will solve the problem because it'll add so much more weight to the car! It'll be interesting to see if/how battery technology develops for high speed performance.

Of course, for normal everyday driving, 0-60 and good handling is all that's really needed!

 

[W0QR]

I agree with eye.surgeon. How many times are you going to 'show off'. When I get mine, I will demo acceleration. But if I had 0-60 in 7 seconds and 500 miles range..I'd take the 500 slow-mo any day.

 

[fadkar]

I agree with eye.surgeon. How many times are you going to 'show off'. When I get mine, I will demo acceleration. But if I had 0-60 in 7 seconds and 500 miles range..I'd take the 500 slow-mo any day.

While I'd love to have 500 mile range, I wouldn't want it at the cost of that much performance!! Elon Musk has always said that he wanted to build a car that people bought not just because it's electric/efficient but because it's just a great car. A 7 second 0-60 time is NOT fun.

We were one of the people that Elon targeted. We were never in the market for EVs. We've never owned a hybrid. In fact, our current car gets 16mpg, our previous one was around 18, and the prior was a Hummer! But after driving around the P85D we got it just because it drives better than the V8 we have in our garage. Not destroying the environment was a side perk that's been growing on me too. We would have never bought one if it was that slow. Maybe they can add an Eco mode that sacrifices the performance for max range. I'd be happy to have that option for long trips.

 

[Gizmotoy]

I agree with eye.surgeon. How many times are you going to 'show off'. When I get mine, I will demo acceleration. But if I had 0-60 in 7 seconds and 500 miles range..I'd take the 500 slow-mo any day.

I'd go back to a high performance ICE. One of the attractions of the Model S to me in the first place is the performance available in a family sedan. It's not the only game in town for that, but it is currently the best (IMO). Take that away and I'll be searching for something else. I'd prefer it was another EV, but short of that, I wouldn't drive a boring EV just to be driving an EV, even if it had range approaching or exceeding that of an ICE. I wouldn't want to suffer every day for long trips that I take once or twice a year.

Fortunately that's why there are a wide range of vehicles for people's differing tastes. More EV options would be much appreciated.

 

[jgs]

Right. The idea proposed is already being used in the AWD variants. The front motor has taller gearing, and as speed increases the front motor plays a larger role in powering the vehicle, which has the added benefit of both making the car more stable at speed while also increasing efficiency.

I've seen this stated many times, and it makes sense. However, is there any source for it other than the TMC echo chamber? It would seem natural for JB Straubel to have written about it in his "Driving Range for the Model S Family" article (Driving Range for the Model S Family | Tesla Motors). But despite going into agonizing detail about torque sleep, rolling resistance and other factors, he doesn't say one single thing about gearing. Using the "dog that didn't bark" method (thank you Sherlock Holmes) we have to at least strongly suspect that even though it seems to make sense, Tesla didn't choose to use different gearing on the front and rear motors.

I'd love to be proven wrong either with reference to a Tesla source or a teardown (but what are the chances someone's done a teardown on a D yet?).

 

[Gizmotoy]

I've seen this stated many times, and it makes sense. However, is there any source for it other than the TMC echo chamber? It would seem natural for JB Straubel to have written about it in his "Driving Range for the Model S Family" article (Driving Range for the Model S Family | Tesla Motors). But despite going into agonizing detail about torque sleep, rolling resistance and other factors, he doesn't say one single thing about gearing. Using the "dog that didn't bark" method (thank you Sherlock Holmes) we have to at least strongly suspect that even though it seems to make sense, Tesla didn't choose to use different gearing on the front and rear motors.

I'd love to be proven wrong either with reference to a Tesla source or a teardown (but what are the chances someone's done a teardown on a D yet?).

You might be right. I think the source was originally someone here. It's definitely a more difficult concept to explain, which may be why it's not fully discussed, or maybe they're just not doing it. If Tesla would hurry up and update their specs page for the AWD models we'd definitively have our answer. We know the rear units on the RWD models use a fixed 9.73:1 reduction.