New Tesla model S jets to 60mph in 2.65 seconds. But why?

Cleantechnica

Drag Times posted a video last week of a new Tesla Model S P90D with Ludicrous Mode enabled scampering to 60 miles per hour in a scant 2.65 seconds. That is seriously quick, especially since the car was equipped with standard 19″ wheels and all season tires. That raises the possibility that the same car with the optional 21″ wheels and performance rubber could go even faster.

tesla s
Previously, Drag Times had set the benchmark time for the P90D with Ludicrous at 2.8 seconds. Which brings up this question — why is this car faster when it has the same specs as the prior car? Inquiring minds want to know. When it comes to anything Tesla, the place to find well informed, inquiring minds is at the Tesla Motors Club forum,where this latest video has sparked a lot of chatter.

Much of that commentary is fairly technical, but the general consensus is that Tesla has already started installing its new 100 kWh battery in its cars without telling anyone. Tesla has pioneered installing larger batteries in its cars but limiting their performance via software to lower power levels. For instance, the company now offers an entry-level Model S called the S 60, but it actually has a 75kWh battery installed that is software limited to just 60kWh.

Tesla offered a Model S 60 for a long time, but it had an actual 60kWh battery. The biggest difference with the new model is that is lists for $4,000 less than the old model. Buyers can elect to make it a dual-motor all-wheel-drive car for an extra $5,000 or unlock the full 75 kWh power of the battery for an additional $8,500. But at $60,000, it offers significant value. Although Tesla declines to release information about sales volumes, the rumor is the new S 60 has gotten a lot of new orders for the company.

The lads at TMC have convinced themselves that the added performance of the latest P90DL is due to it having a 100 kWh battery that is software limited to 90 kWh. That certainly explains why the “same” car is now quite a bit faster.

A battery charges slower the closer it gets to a full state of charge. For instance, a Tesla with an empty battery can get an 80% recharge in about 30 minutes at a Tesla Supercharger location. But getting to a 100% state of charge will take another 30 minutes or more. One of the advantages of the software-limited battery is it thinks it is a larger battery when it comes to recharging times. Therefore, the driver can get to an 80% SOC quicker in a software-limited battery. That’s an important benefit out in the real world and away from the drag strip.

There’s a similar effect when it comes to discharging the battery and providing power to the car to jump off the line.

Enjoy the video!

Source: Cleantechnica. Reproduced with permission.

Comments

7 responses to “New Tesla model S jets to 60mph in 2.65 seconds. But why?”

  1. Antony Day Avatar
    Antony Day

    Power vs capacity – know the difference..
    “Tesla has pioneered installing larger batteries in its cars but limiting their performance via software to lower power levels. For instance, the company now offers an entry-level Model S called the S 60, but it actually has a 75 kWh battery installed that is software limited to just 60 kWh”

    Tesla is limiting the accessible energy *capacity of the battery, not the power. Tesla is not limiting the *performance of the battery it is limiting how much energy can be stored and used by the car. Big difference. You can talk about the power of a motor and limiting it’s performance , something Tesla does by enabling Ludicrous mode for a few extra $$.

    also :
    “The lads at TMC have convinced themselves that the added performance of the latest P90DL is due to it having a 100 kWh battery that is software limited to 90 kWh. That certainly explains why the “same” car is now quite a bit faster.”
    Nope again… Extra , hidden energy capacity does not make a car faster… for the same reasons as above

    1. David Osmond Avatar
      David Osmond

      Hi Antony, this is what emir-t says on the Tesla discussion forum:
      “Anyway back to main topic. Larger capacity cells mean they can also discharge quicker at lower C rates, giving higher power outputs. Batteries love low C rates. (C rate is the discharge current as percentage of capacity. If a 3.1Ah cell discharges 3.1Amps, it is 1C. If it discarges at 15,5Amps, that’s 5C) New pack will be 3,7*74 = 274Ah capacity. At fully charged voltage of 403V that means, at a 5C peak discharge rate, 552kW. This converts to better performance throughout.”

    2. ROBwithaB Avatar
      ROBwithaB

      Was about to explain charge/discharge rates, but I see that somebody already did that below.

    3. Haggy Avatar
      Haggy

      Your explanation is wrong, and history shows it. When I first saw the “Why?” question, I didn’t know what to expect. Somebody might have been asking why the car needs to do it in the first place. It turned out that the question was why the car now accelerates faster. It also turns out that both questions are related.

      When Tesla first came out with the P85+ it went from 0-60 in 3.9 seconds (or 4.1 seconds depending on who tested it.) Tesla then added AWD, because they wanted AWD. A side effect was that by having two motors, no drive shaft, and electronic control down to the millisecond over which motor is doing what, they were able to shave about a second off things and go from 0-60 in 3.1 seconds, all while making the car more energy efficient.

      That was insane. Literally, Tesla called it “insane” mode. Then Tesla looked into increasing the battery size, and changing the contactors to inconel to handle the higher current flow from the larger battery. Again, the intent was to have a bigger battery and provide more range, but the side effect was that the 0-60 time dropped to 2.8 seconds.

      Tesla’s intent from the onset was to change the perception of the EV. People saw them as ugly, slow, with limited range, no storage space since it was used up by batteries, and with no way to charge quickly. Tesla shattered every one of those perceptions. 3.9 seconds was necessary. The rest were all side effects of other improvements. If the latest came about because the battery was again upgraded, that would be entirely consistent with what happened last time.

      The car isn’t doing anything near pushing the limits of how fast an electric motor can turn. Getting it more power and having the ability for it to handle the power are the factors that are changing. The time might continue to drop, not because Tesla needs to make the car go faster, but because people think they need more range.

  2. Stan Hlegeris Avatar
    Stan Hlegeris

    Why? Because Tesla’s strategy has always been to enter the market from the high end. This approach has already worked, as Tesla now outsells every other model in the “luxury” segment.

    I agree that no one needs that much acceleration. But it gives Tesla extraordinary publicity far more effective than any advertising campaign could ever be, regardless of budget. It’s just good business.

  3. Miles Harding Avatar
    Miles Harding

    With no exhaust noise, it has to do something to impress.

    So, does this mean another bunch of $1M plus supercar owners are going to get a loaded Tesla at 1/4 the price?

    1. Haggy Avatar
      Haggy

      Probably not. It may be able to do 0-60 faster and might even do the 1/4 mile faster, but it’s not designed for sustained racing. In the real world (i.e. street legal use) once you are up to the speed limit, all the theoretical capabilities above it go out the window. An owner of a supercar might like the idea that his car can do incredible things, just as most SUV owners know their vehicles are good for use off the road, even though they never tried it and never will. And if you are planning to drive not much faster than the speed limit, the rest comes down to what a car can do in theory.

      I don’t mean in any way to disparage owners of supercars. I’m sure many of them legitimately use the cars in ways that push the limits and they aren’t looking for a family sedan.

      You are also far less likely to find Tesla owners who are supercar wannabes than you might think. Acceleration is a fun feature, and makes it great for changing lanes quickly or accelerating from stop lights, but Tesla owners aren’t likely to buy the car so they can drive like kids who want to show off what they have. So while there may be overlap, people will buy each type car for a different reason.

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