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I don't know much about the mechanics or engineering of the Model S, but I'm going to take a gander and say that much of that extra weight comes from the batter

I don't know much about the mechanics or engineering of the Model S, but I'm going to take a gander and say that much of that extra weight comes from the battery pack (and other parts of the non-traditional drivetrain), which isn't a (huge?) factor in a crash test (though I could be wrong). Just checked - yep - the battery weighs an estimated ~ 545kg or 1200 lbs [1]. I'd expect the structural components to actually be lighter than competitors, given that they're fabricated with aluminum vs steel. [1] http://www.teslamotors.com/fr_CA/forum/forums/model-s-battery-0 http://www.teslamotors.com/fr_CA/forum/forums/model-s-batter...

mikeash 13y ago
How much does the gas tank, motor, radiator, transmission, etc. in a normal car weigh? Have to subtract that out of the 1,200lbs to see how much extra is added.
- akira2501 13y ago
  Mid-Range Estimates: Engine: 300 to 450 pounds Transmission: 120 to 140 pounds Gas Tank: 20 to 25 pounds Radiator: 20 to 30 pounds So, roughly 460 to 645 pounds. Add 110 pounds for 15 gallons of gas. The comparison is a little more difficult than this though, because the batteries just store energy. The Model S still has a (416hp) motor, there are a few other differences (regenerative vs standard brakes) and equivalencies (inverter vs alternator).
  - mikeash 13y ago
    Yep, it gets a bit tough, but that 460-645lbs range seems like a decent stab at it. I don't get the impression that the Model S's motors are all that heavy compared to the rest of this stuff, but I could be wrong. I'd also wager that the Model S needs a full set of mechanical brakes for emergency purposes, since it still needs to be able to stop safely even if all the electronics suddenly quit while going down the highway at 70MPH. And then there's the question of whether you compare against a 416hp motor, or a less powerful gas motor that would be more typical for a car that size....
    - akira2501 13y ago
      A Chevy 383 can make about 400hp+ in about 620 pounds. If we choose all our numbers for comparable cars that are highly in favor of the Tesla, we're still only likely going to match the weight of the Tesla's battery pack alone. The Model S curb weight is 4,647 pounds. A Cadillac STS, which is 5" narrower but very nearly the same in every other dimension as the Model S is only 3,922 pounds. That leaves the Model S 725 pounds heavier, still quite a bit of difference.
      - ssmoot 13y ago
        It's in the ball-park though. Your assessment seems pretty fair. I've seen some call the Tesla's weight "insane" though. My old (still current gen) Volvo S80 T6 weighed 4,400lbs IIRC. I assume that's "dry" weight. Since a Model S is always "dry" aside from a gallon of wiper fluid or the like they probably weigh just about the same on the road. And the Model S is a bigger, faster car. My Jeep Grand Cherokee (with the panoramic sunroof option I didn't actually have) weighed 5,500lbs. Again, I assume like motorcycle manufacturers that car manufacturers are listing the "dry" weight. So that baby is probably over 3 tons wet when optioned up. The Cadillac seems on the light side for it's class. Even so, "wet" the difference in weight is probably one passenger. Despite it being a smaller car (5" actually seems pretty significant IMO, that's 5" less wiggle room to stay in your lane!). That's (I assume) the worst-case-scenario highest capacity Tesla. Performance is far in excess of most cars on the road already. Capacity with smaller battery packs will surely improve. It seems like weight can only go down from here, and it's not out of line with it's competition as is.
- ssmoot 13y ago
  The 20+ gallon tank in my old Jeep Grand Cherokee would add over 300lb to the "wet weight". It also took (IIRC) an insane 7L of oil. So that stuff adds up.

mikeash 13y ago

How much does the gas tank, motor, radiator, transmission, etc. in a normal car weigh? Have to subtract that out of the 1,200lbs to see how much extra is added.

akira2501 13y ago
Mid-Range Estimates: Engine: 300 to 450 pounds Transmission: 120 to 140 pounds Gas Tank: 20 to 25 pounds Radiator: 20 to 30 pounds So, roughly 460 to 645 pounds. Add 110 pounds for 15 gallons of gas. The comparison is a little more difficult than this though, because the batteries just store energy. The Model S still has a (416hp) motor, there are a few other differences (regenerative vs standard brakes) and equivalencies (inverter vs alternator).
- mikeash 13y ago
  Yep, it gets a bit tough, but that 460-645lbs range seems like a decent stab at it. I don't get the impression that the Model S's motors are all that heavy compared to the rest of this stuff, but I could be wrong. I'd also wager that the Model S needs a full set of mechanical brakes for emergency purposes, since it still needs to be able to stop safely even if all the electronics suddenly quit while going down the highway at 70MPH. And then there's the question of whether you compare against a 416hp motor, or a less powerful gas motor that would be more typical for a car that size....
  - akira2501 13y ago
    A Chevy 383 can make about 400hp+ in about 620 pounds. If we choose all our numbers for comparable cars that are highly in favor of the Tesla, we're still only likely going to match the weight of the Tesla's battery pack alone. The Model S curb weight is 4,647 pounds. A Cadillac STS, which is 5" narrower but very nearly the same in every other dimension as the Model S is only 3,922 pounds. That leaves the Model S 725 pounds heavier, still quite a bit of difference.
    - ssmoot 13y ago
      It's in the ball-park though. Your assessment seems pretty fair. I've seen some call the Tesla's weight "insane" though. My old (still current gen) Volvo S80 T6 weighed 4,400lbs IIRC. I assume that's "dry" weight. Since a Model S is always "dry" aside from a gallon of wiper fluid or the like they probably weigh just about the same on the road. And the Model S is a bigger, faster car. My Jeep Grand Cherokee (with the panoramic sunroof option I didn't actually have) weighed 5,500lbs. Again, I assume like motorcycle manufacturers that car manufacturers are listing the "dry" weight. So that baby is probably over 3 tons wet when optioned up. The Cadillac seems on the light side for it's class. Even so, "wet" the difference in weight is probably one passenger. Despite it being a smaller car (5" actually seems pretty significant IMO, that's 5" less wiggle room to stay in your lane!). That's (I assume) the worst-case-scenario highest capacity Tesla. Performance is far in excess of most cars on the road already. Capacity with smaller battery packs will surely improve. It seems like weight can only go down from here, and it's not out of line with it's competition as is.
ssmoot 13y ago
The 20+ gallon tank in my old Jeep Grand Cherokee would add over 300lb to the "wet weight". It also took (IIRC) an insane 7L of oil. So that stuff adds up.