S85 Owners: Do you wish you had bought S60 instead

[wndrful]

Taking the unused gas in the tank analogy a little further. It is Saturday morning so we can spend time doing "what if" scenarios. :smile:

Consider a hypothetical buyer who drives locally and never does really need the extra range of an 85.
Lets look at impact of buying 60 or 85 for that buyer.

100K miles of driving == 1000 gallons of gas (~100mpg ) == 4000$ spend for "gas"

However, 85 has already extra "gas"/charge of $8K (2000 gallons eq) which is never really used for most of the time (for this buyer).

Now if the buyer sells the car after 4years/100k miles and gets back additional $4k back for 85 over 60 then at the bottomline buying an 85 costs $4k for a "gas" tank which wasn't really used.

In other words, at the end of 4 years, a 60 owner spent $4k on gas whereas a 85 owner has spent $8k total (4k+4k) on gas.
Thus the effective mpg for 85 is around 50 (almost half of a 60).

The numbers work out different if we look at 8yrs/200kmile scenario. So if you are the kind of guy who upgrades cars every four years, and will sell his current S to buy 2018 Model S with 400hp/600hp - 260miles/360miles then he/she should stick with S60.

 

[dsm363]

Taking on A7 gas tank analogy. The reason people don't pay premium for bigger gas tank is that there are gas stations almost around the block.
Similarly, I am putting my money on future that around the time Tesla hits 200K+ cars there would be a third party supercharger every 50 miles.
After that a "bigger gas tank" would be a fairly moot point. So think of buying a car for the next four years of usage and charging scenarios. Not for 8-10 years.

Even then there are people who want a bigger tank or battery pack. If you can skip three Superchargers and get to the one you want or to your destination even that is ideal. Superchargers every 50 miles would certainly allow travel with smaller battery packs or make it easier.

 

[dsm363]

Taking the unused gas in the tank analogy a little further. It is Saturday morning so we can spend time doing "what if" scenarios. :smile:

Consider a hypothetical buyer who drives locally and never does really need the extra range of an 85.
Lets look at impact of buying 60 or 85 for that buyer.

100K miles of driving == 1000 gallons of gas (~100mpg ) == 4000$ spend for "gas"

However, 85 has already extra "gas"/charge of $8K (2000 gallons eq) which is never really used for most of the time (for this buyer).

Now if the buyer sells the car after 4years/100k miles and gets back additional $4k back for 85 over 60 then at the bottomline buying an 85 costs $4k for a "gas" tank which wasn't really used.

In other words, at the end of 4 years, a 60 owner spent $4k on gas whereas a 85 owner has spent $8k total (4k+4k) on gas.
Thus the effective mpg for 85 is around 50 (almost half of a 60).

The numbers work out different if we look at 8yrs/200kmile scenario. So if you are the kind of guy who upgrades cars every four years, and will sell his current S to buy 2018 Model S with 400hp/600hp - 260miles/360miles then he/she should stick with S60.

If someone is buying the biggest and the best every four years and can afford to do so (and wants the range ) why should they buy the 60kWh Model S?

 

[qwk]

Most likely, I returned from the trip July 1st and I live very close to the Hawthorne SC.



I'm not sure, but I do know that Sam made it: LA>Virginia and back in his 60kw.
I met him during the Tesla scavenger hunt in Los Angeles, man, that dude's amped!




Exactly. Do I think paying an additional $8k over a 60kw (w/ $2k SC enabled) makes intuitive sense, yup I do, but I suspect 90% of Model S owners will never actually "need" the additional range. If coming up with the $8k is a deal breaker, or even a stretch and you'd rather put it towards options that you'll use every day Tech Package/Leather/Sun Roof - you'll be fine in a 60kw.

If you were buying an ICE car, say an Audi A7, and they offered an option to pay $8k for a 22 gallon gas tank rather than the standard 16gal tank, would you buck up for it? If you live in the desert or Texas where a 100mile drive each way is part of a regular commute, then no question, you'd buy it, similarly, if you know you need the range, purchase the 85kw, but if you live in Santa Monica and you're plan is to use the car to pickup the kids and run errands, I'd wager you'd never use the extra 50miles - even on an annual trip up the coast to Santa Barbara or SanFran, you'll make the superchargers - keep the $8k and in my opinion, buy some TSLA stock.

The 60MS can (and has) made it cross-country exclusively using superchargers, this will only get easier in the future. Oh, you can still do 70mph+ most of the way, I'd wager that there are many more 120mile sections where can drive full-dusche and break triple-digits, than 170-200mile stretches where you'd need to drive 55mph. You'll learn your car and when to back-off the speed during the long stretches or when heading into the Rocky's.

On my trip without superchargers, I had the cruise around 62mph and I'd consistently average 225miles and even squeezed 256miles out of a charge - no doubt a 60kw can make any supercharge route with ease if you take it easy during the longer stretches. Absolutely worst case, you find yourself on a cross-country trip and can't quite make the next supercharger, it's not an exaggeration to say there are campsites at practically every other exit in America - so during that one hour you're stuck charging during the lifetime you own a 60kw, you could get angry, or you can think of all the other toys you bought with that $8,000 dollars.
- Robs

We will have to have this discussion after 125k miles, when the battery warranty is up. 125k miles is a few years of driving for a lot of people here. Then what does one do when a battery contactor fails? I can see a lot of eyeballs popping out of people's heads when they see the Tesla bill. Tesla repairs are anything but cheap.

 

[Treker56]

I have had an S60 for a year now and do not regret saving that $8K. Have a P85 loaner for the weekend but while the acceleration is awesome of course I do not need it for day to day driving . In fact it seems harder to maintain a good avg kWh on the P85. I am sure in 5 years or so when the Gigafactory will be up Tesla will offer a battery replacement/upgrade program which will make all these conversations moot.

 

[liuping]

I am interested to find out if there are 85 owners who have not used super charger option, who did not need last 60 miles until now, whose need were really fulfilled by 60 but bought 85 just because they may need it and in case...

It's not just whether the 60kWh battery has enough range for you, it's also how much of your driving is in the lower 10-20% of the battery's charge.

If you have an 85 and rarely use the last 60 miles, you are not dropping the battery below 20%. This means your battery will last significantly longer.

- - - Updated - - -

Now if the buyer sells the car after 4years/100k miles and gets back additional $4k back for 85 over 60 then at the bottomline buying an 85 costs $4k for a "gas" tank which wasn't really used.

That is a big assumption. It's entirely possible the 85's will be selling for more than $4000 over 65's. The 65 will have already lost enough range at that point to be well below 200 miles range, which is a bit of a magic number for many people.

 

[wndrful]

If you have an 85 and rarely use the last 60 miles, you are not dropping the battery below 20%. This means your battery will last significantly longer.

20% ! Really?! In any case, in my regular use, neither do I ever go below 30% on my battery either.
Why is that everyone talks as if 85 batteries are golden but the batteries of 60 are made by some cheap Chinese factory in Western China owned by your mother in laws second cousin who never liked you and would look for any opportunity to spit in your beer glass?
Since the component cells are identical I would attribute age related degradation to be the same for both. Tesla offers 8 years unlimited to 85 pack and it is good enough confirmation for me on age-reliability of 60 pack.
As for the mileage related degradation, if Panasonic studies are any indication, if daily usage is managed within 50% of capacity, we should see less than 5% degradation at 500 cycles and less than 10% degradation at 2000 cycles. This is equivalent to 100K and 400K for 60 and 125K-500K for 85.

On the flip side, I would venture out on a limb to say that 60 pack, due to it's over-designed cooling system, will have better temperature management and better life cycle.

 

[liuping]

If you have an 85 and rarely use the last 60 miles, you are not dropping the battery below 20%. This means your battery will last significantly longer.

20% ! Really?! In any case, in my regular use, neither do I ever go below 30% on my battery either.
Why is that everyone talks as if 85 batteries are golden but the batteries of 60 are made by some cheap Chinese factory in Western China owned by your mother in laws second cousin who never liked you and would look for any opportunity to spit in your beer glass?
Since the component cells are identical I would attribute age related degradation to be the same for both. Tesla offers 8 years unlimited to 85 pack and it is good enough confirmation for me on age-reliability of 60 pack.
As for the mileage related degradation, if Panasonic studies are any indication, if daily usage is managed within 50% of capacity, we should see less than 5% degradation at 500 cycles and less than 10% degradation at 2000 cycles. This is equivalent to 100K and 400K for 60 and 125K-500K for 85.

20/90 is just a rule of thumb, they are not the absolute optimal numbers, but they are easy to live with. If you do not go below 30% that is even better.

I don't recall anyone suggesting the 60kWh pack is made from cells that differ in anyway from the 85kWh packs.

It's is just easier to keep the 85 pack in the sweet spot for maximum battery life. If you keep you 60 between 20% and 90%, you could be keeping an 85 between 30% and 86%, so the 85 pack will degrade less over time.

If you want to go with Panasonic data: 500 50% cycles are only 53000 miles on a S60, assuming you are diving EPA rated miles (212). Realistically I've average about 90% of EPA milage, so that would be 5% degradation after 42.4k miles if you could stay in the middle 50% charge range.

 

[wndrful]

Typically, lithium battery charge cycles are quoted as % of charge/discahrge per cycle. In other words, if only 50% charge/discharge cycle then it is considered .5 cycle. If 60% charge discharge then it is considered 0.6 cycle.
Panasonic study just quotes data upto 3000 cycles for charge/discharge in 4.05 v to 3.6v. They don't specify scaling or % charge/discharge rate.

Since scaled 3000 cycles sound to good to be true, I assumed it is unscaled and assumed it was 66% charge/discharge and came up with 2000 cycles (3000*0.66).
I typically run at 300w/mi so 60kwh => 200miles so 2000 cycles => 400Kmiles

 

[gg_got_a_tesla]

It's probably futile to argue one way or another. And, we have little data on long term degradation for either pack.

If one can afford to buy an 85 and has long commutes, cold winters and/or has range anxiety in general, an 85 makes perfect sense.

If a 60 serves one's range needs pretty much all the time, even if they can afford an 85 (as in my case), they can opt for the 60.

For me personally, less is more. Many of us are vested in Tesla to conserve on several fronts and this was a start for me.

The money I saved - or rather, my financially-prudent wife helped save - has done very well in TSLA and in our son's 529 college fund. In 8 years or later, I can opt for whatever larger baseline pack Tesla may have for the MS at that time.