Range between Models - is the 70KWH more than expected?

[thegruf]

If an 85KWH range is typically 235 miles then:

60 235/85*60 = 165 miles
70 235/85*70 = 193 miles
90 235/85*90 = 248 miles

From the 90% thread http://www.teslamotorsclub.com/showthread.php/50171-What-s-your-90 most 70KWH owners are reporting iro 210 miles
Thats barely 25 miles less than an 85KWH and some extremes are almost at parity.

Or alternatively, the 85 should be a 20% improvement over a 70.
So if the 70 is 210 miles then the 85 should be 255 miles.

However you look at it, seems to make the 70D excellent value.

Another possibilty is that the drivetrain operates considerably more efficiently at the lower pack voltage of the 70, though I would have expected the opposite as current for equivalent power is lower.

 

[gizmoboy]

My 70 is an excellent value.

The thing I (slightly) regret about not going for the 85D is that second or so of 0-60, which translates to a palpable increase in "oomph".

Not sure it and the incremental range are worth $10K to me though.

 

[kptesl]

The reason the lower energy packs are "more efficient" is that the weight of the car is lower. As you increase battery pack capacity (thus weight), the return on range is diminishing.

 

[peteyswift]

How much lighter is the 70D than an 85D or P85D? I drove one without the pano roof or air suspension and I swear it felt pretty swift to me!

 

[thegruf]

The reason the lower energy packs are "more efficient" is that the weight of the car is lower. As you increase battery pack capacity (thus weight), the return on range is diminishing.

Fair point, and I had considered it, but this doesnt explain the disproportionetly high range that the 70D is reporting. The 60D is reporting closer to expectation.

 

[AWDtsla]

70D looks to be even more efficient than stated (i.e. rated miles), I think it's still a bit of a mystery where it's coming from. But it's an even better deal than it looks like on paper.

 

[Adrian]

The major difference is available battery power:
S60: 60 kWh (some have reported 60.2)
S70: 65 kWh
S85: 75 kWh (some have reported 76)

 

[CHGolferJim]

In recent driving in the temperate Carolinas (50-65 *F), I'm seeing 200 miles of actual range on interstates at 65-70 mph (extrapolated from achieving 160 miles numerous times for 90% to 10% SOC, and other 20/10% multiples).

 

[FloridaGary]

The 70 is a better value and why I purchased one. Living in Florida doesn't require a dual motor which is an additional savings. I drive the interstate every day (42 mi round trip) and only need one charge to get through a 5 day work week.

 

[GasKilla]

The 70 is a better value and why I purchased one. Living in Florida doesn't require a dual motor which is an additional savings. I drive the interstate every day (42 mi round trip) and only need one charge to get through a 5 day work week.

During hurricane season you may want to charge up every night

 

[thegruf]

During hurricane season you may want to charge up every night

... off a wind turbine?

 

[FloridaGary]

During hurricane season you may want to charge up every night

Good point. Since hurricane warnings are usually days in advance, it would be a good practice to charge daily when the first sign is reported.

 

[FloridaGary]

During hurricane season you may want to charge up every night

Good suggestion.

 

[GasKilla]

Good suggestion.

I grew up on the Gulf Coast and at the first sign of a hurricane in the Gulf my dad would fill up his car. That's the beauty of an EV, every morning you can wake up with a "full tank" without having to leave your house.

 

[rowdy]

Getting back to the original question, the difference in range makes sense if you think about how the battery is constructed. The battery in the 70 is meant to have 14 modules instead of the 16 in the 85. So the actual capacity (relative to 85) becomes:

85/16*14 = 74.375kwh

Each module weighs around 25kg so with 2 fewer modules you have 50kg in weight savings which will show up in improved efficiency.

In short, 70 is really good value if on a budget and much closer in range than many people realise.