....to know without any doubts as to whether its lighter than 4630 lbs???

I chose 60 over 85 mainly because its assumed weight loss.

It would put me at ease, if I have a real world number.

djp | 25 Gennaio 2013

Received a written reply from Tesla confirming curb weight and battery cell type for the 60 kWh cars. Recap of 85 kWh vs 60 kWh information:

-Curb weight: 4647 lbs 85 kWh, 4464 lbs 60 kWh -EPA miles per charge: 265 miles 85 kWh, 208 miles 60 kWh -EPA MPG electric equivalent: 89 MPGe 85 kWh, 95, MPGe 60 kWh -Both cars use Panasonic 3.4 ah 18650 Li-Ion cells, the 60 kWh cars use fewer.

PaceyWhitter | 25 Gennaio 2013

200 lbs is nothing. It doesn't explain the 6 MPGe increase.

schoendp | 25 Gennaio 2013

The weight difference as a % of the car is a little over 4%. This would increase the mileage by about 4 MPGe. I assume the other 2 MPGe is from decreased hp.

Flaninacupboard | 25 Gennaio 2013

Lower curb weight (5%) is 5% less rolling energy required, still a decent impact on the EPA highway test (with it's comparatively low speeds), and a much more direct 5% reduction in the city test (5% less mass to accelerate and brake). There's also less battery mass to keep at the correct temperature (hot or cold). Final drive ratio may also be different (lower top speed is offered) and inverter profile is different, perhaps allowing more efficient operation in the lower power band. Also, an inverter with 45kw less power output will require less cooling, so possibly smaller air intakes, certainly the the 175kw 40kwh car needs less cooling than the 310kw performance 85kwh car!!

Brian H | 25 Gennaio 2013

Yes, the 60 "burns" less energy accelerating, because it doesn't do it as strongly. So the 5-cycle test shows that. But steady cruising wouldn't be affected by that, so the difference at steady speed would be from the weight difference, only.

nickjhowe | 25 Gennaio 2013

Congrats @djp - real data for a change instead of wild speculation.

ddruz | 25 Gennaio 2013

@nickjhowe - djp lifted that information verbatim from my post on the Punch List thread this morning noting the response from my Tesla rep. I'm sure djp simply forgot to credit the source.

nickjhowe | 25 Gennaio 2013

In that case thanks @ddruz!!!! Not sure what magic you worked to get that much detail out of Tesla, but keep it up.

ddruz | 25 Gennaio 2013

I made a typo in the recap which djp copied and pasted above. The battery cells are 3.1 ah not 3.4 ah. Corrected:

Received a written reply from Tesla confirming curb weight and battery cell type for the 60 kWh cars. Recap of 85 kWh vs 60 kWh information:

-Curb weight: 4647 lbs 85 kWh, 4464 lbs 60 kWh -EPA miles per charge: 265 miles 85 kWh, 208 miles 60 kWh -EPA MPG electric equivalent: 89 MPGe 85 kWh, 95, MPGe 60 kWh -Both cars use Panasonic 3.1 ah 18650 Li-Ion cells, the 60 kWh cars use fewer.

RedShift | 26 Gennaio 2013

ddruz:

Thanks for the info! I was expecting 60 kwh to weigh around 4300 lbs, but ah, I will take it :-) any weight loss is better than none.

Hills | 18 Marzo 2013

Does anyone know the weight of the entire battery pack for 85 Kwh? Including the enclosure for the battery.

jat | 18 Marzo 2013

@BrianH - at steady speed, you are using energy only to overcome drag and rolling resistance, so the weight has very little to do with it. The weight mainly comes into play when accelerating and decelerating, as the force required to change the speed is directly proportional to the mass.

Got Amped | 18 Marzo 2013

@jat - I'd add that weight has a linear effect when changing elevation also. Not sure if the EPA cycle models flat ground or has simulated hills and valleys - anyone know the specifics?

Brian H | 18 Marzo 2013

jat; I'd expect rolling resistance to be affected by weight, at least to some exent.

RedShift | 18 Marzo 2013

LRR tires plus aero wheels minus 150 pounds = may be 15 miles of extra range?

Andre-nl | 19 Marzo 2013

Brian H,

The question is not whether weight increases rolling resistance (it does, proportionally), the question is how big a factor rolling resistance is compared to aerodynamic drag. In highway use the 4% reduction in weight is negligible.

Another factor that reduces the effect of weight in an EV is regenerative braking. So even urban consumption will be decreased by less than 4%.

I'd be surprised if the 4% reduction in weight yielded more than 2% recuction in energy consumption.

Does the 60 kWh version come with different tires and/or rims?

Hans (Amsterdam) | 19 Marzo 2013

I would expect that EPA tested 85kWh with 21" and 60kWh with 19" tyres. Unfortunately EPA does not mention this. Weight only cannot make the difference between 89 en 95 MPGe.

At 30mph about 75% rolling resistance and 25% aerodynamic drag. At 60mph 45% / 55% At 80 mph 30% / 70%

For acceleration power needed is lineair with mass.

Received a written reply from Tesla confirming curb weight and battery cell type for the 60 kWh cars. Recap of 85 kWh vs 60 kWh information:

-Curb weight: 4647 lbs 85 kWh, 4464 lbs 60 kWh

-EPA miles per charge: 265 miles 85 kWh, 208 miles 60 kWh

-EPA MPG electric equivalent: 89 MPGe 85 kWh, 95, MPGe 60 kWh

-Both cars use Panasonic 3.4 ah 18650 Li-Ion cells, the 60 kWh cars use fewer.

200 lbs is nothing. It doesn't explain the 6 MPGe increase.

The weight difference as a % of the car is a little over 4%. This would increase the mileage by about 4 MPGe. I assume the other 2 MPGe is from decreased hp.

Lower curb weight (5%) is 5% less rolling energy required, still a decent impact on the EPA highway test (with it's comparatively low speeds), and a much more direct 5% reduction in the city test (5% less mass to accelerate and brake). There's also less battery mass to keep at the correct temperature (hot or cold). Final drive ratio may also be different (lower top speed is offered) and inverter profile is different, perhaps allowing more efficient operation in the lower power band. Also, an inverter with 45kw less power output will require less cooling, so possibly smaller air intakes, certainly the the 175kw 40kwh car needs less cooling than the 310kw performance 85kwh car!!

Yes, the 60 "burns" less energy accelerating, because it doesn't do it as strongly. So the 5-cycle test shows that. But steady cruising wouldn't be affected by that, so the difference at steady speed would be from the weight difference, only.

Congrats @djp - real data for a change instead of wild speculation.

@nickjhowe - djp lifted that information verbatim from my post on the Punch List thread this morning noting the response from my Tesla rep. I'm sure djp simply forgot to credit the source.

In that case thanks @ddruz!!!! Not sure what magic you worked to get that much detail out of Tesla, but keep it up.

I made a typo in the recap which djp copied and pasted above. The battery cells are 3.1 ah not 3.4 ah. Corrected:Received a written reply from Tesla confirming curb weight and battery cell type for the 60 kWh cars. Recap of 85 kWh vs 60 kWh information:

-Curb weight: 4647 lbs 85 kWh, 4464 lbs 60 kWh

-EPA miles per charge: 265 miles 85 kWh, 208 miles 60 kWh

-EPA MPG electric equivalent: 89 MPGe 85 kWh, 95, MPGe 60 kWh

-Both cars use Panasonic 3.1 ah 18650 Li-Ion cells, the 60 kWh cars use fewer.

ddruz:

Thanks for the info! I was expecting 60 kwh to weigh around 4300 lbs, but ah, I will take it :-) any weight loss is better than none.

Does anyone know the weight of the entire battery pack for 85 Kwh? Including the enclosure for the battery.

@BrianH - at steady speed, you are using energy only to overcome drag and rolling resistance, so the weight has very little to do with it. The weight mainly comes into play when accelerating and decelerating, as the force required to change the speed is directly proportional to the mass.

@jat - I'd add that weight has a linear effect when changing elevation also. Not sure if the EPA cycle models flat ground or has simulated hills and valleys - anyone know the specifics?

jat;

I'd expect rolling resistance to be affected by weight, at least to some exent.

LRR tires plus aero wheels minus 150 pounds = may be 15 miles of extra range?

Brian H,

The question is not whether weight increases rolling resistance (it does, proportionally), the question is how big a factor rolling resistance is compared to aerodynamic drag. In highway use the 4% reduction in weight is negligible.

Another factor that reduces the effect of weight in an EV is regenerative braking. So even urban consumption will be decreased by less than 4%.

I'd be surprised if the 4% reduction in weight yielded more than 2% recuction in energy consumption.

Does the 60 kWh version come with different tires and/or rims?

I would expect that EPA tested 85kWh with 21" and 60kWh with 19" tyres.

Unfortunately EPA does not mention this.

Weight only cannot make the difference between 89 en 95 MPGe.

At 30mph about 75% rolling resistance and 25% aerodynamic drag.

At 60mph 45% / 55%

At 80 mph 30% / 70%

For acceleration power needed is lineair with mass.