85D vs 90D? Upgrade worth $3,500?

I'd do it.

If the 90D was out when I got my 70D, I would've likely spend the $13k to upgrade. I felt the $10k for the 85D wasn't worth it.


Also, find the thread here about 90D decreased range or something like that. Many 90D owners are complaining that the promised 6% at 90% charge may not be there after a while. Sure, it could be user error and not charging/discharging enough, but it's also a new battery chemistry.

 

There is no acceleration difference between my 90D and the 85D I test drove. I don't regret spending more for the 90D versus the 85D, but it really seems like the new battery chemistry degrades faster than the older 85kwh pack. I've lost 6 rated miles in two months and other owners have reported similar losses early in their ownership.

 

Based on this table which I got from TeoTeslaFan on the TeslaMotors forum


Assuming that the 6% increase in battery capacity leads to faster supercharging times (is there a thread on this somewhere?), extrapolating from the data, you're looking at a savings of ~5mins for a ~500mile one-way trip.

 

You will need objective test methodology to test small differences in acceleration. Just saying you test drove a 90D and a 85D is fairly meaningless. Also, basing range "loss" compared to what the car said at delivery isn't really accurate either. The car has to adjust to your driving patterns and will adjust or "learn" over time. That is completely unrelated to battery chemistry and would have to be objectively tested.

 

Anything to back this up? From everything I read, the car uses it's own algorithm to determine rated miles, and it's not related to your driving pattern (that's projected miles).

 

Either/or, the algorithm output will vary. Just because your Tesla says "X" miles at delivery for a certain charge doesn't mean it will stay that way forever. Certainly doesn't automatically mean your battery is degenerating already.

 

It's not either/or, it's apples and oranges. There's a big difference between "the car needs to adjust to your particular driving" and "the algorithm calculates battery capacity, unrelated to your driving style".

And of course it wont stay that way forever, there is battery degradation. The point Jool was making was that since the 90D uses a different battery chemistry than the 85D, he [and many others] suspect that the initial drop in rated range is higher with the new battery chemistry. From the few people that posted, he may be correct.

 

Performance data for the 85D, 90D, and other models can be found here: http://www.teslamotorsclub.com/showthread.php/46923-0-60-30-50-50-70-comparitive-times-for-70D-85D-P85D

As for the degradation, when I first posted about my decrease in rated range a while back I got plenty of skeptical replies but others have recently posted about their issues with the 90D's range. I would love to believe that it's just my driving habits but somehow I doubt that is the case at this point. Just giving my honest opinion based off of my short ownership experience.

 

I've owned an 85 (non-D) since February, before the 90 was available, so that wasn't a choice. If I were buying again, I wouldn't spend an extra $3,000 for a mere 15 miles or so of additional range. The 85's range is just fine, and the 85D's is even better. I wouldn't mind more range, but the price isn't right for such a small increase, at least not to me. I don't think there's anything else of note. It's a modified chemistry, which could be good or bad, so it's also a bit of a risk until we see how it works out longer-term.

 

I got my 90D on September 9th and my brother got his 85D in mid October. I started off close to 416km at 90%, and I seem to have settled to 405km over the last few weeks. It's to early to say if my brother's car has settled like mine, but he currently gets 389km at 90%. We both agree it not worth it for the price of $3400. I do like the cool 90D badge (but still not worth it). I would get SAS, HIFI sound, premium, or just about anything else first. Only if you still have money to burn then get the 90D.

Btw, both cars drive identically.

 

Yet you are completely missing the point that 90Kwh batteries are still fairly new and certainly wouldn't be degrading that fast. Tesla isn't going to release a battery that did.

 

Lol, you do realize that we're all guinea pigs?

I understand you have a 90D on order, so you're biased that it'll be perfect.

And Tesla never makes mistakes. I agree. You'll get 4 USB ports, a SSD, 691hp, 300 rated miles, autopilot in several months, the final iteration of the drive unit, a windshield that transmits ezpass, etc. You get the point

 

For the record, my 85D has close to 20 000km and I also get 389km of rated at 90% SOC.
When I got it new, a full range change would give me around 436km. Now it's around 428.

According to those numbers I got 2% of degradation for the first 20 000kms but hey, we're speculating here since it's not like the cells cannot be charged to 4.2V anymore, the SOC is simply getting lower faster because the internal resistance of the cell is increasing. The "full" point does not change. It's the length of travel between the empty and full point. Only Tesla knows that for sure.

 

I have ~70,000 miles on two P85's, both have settled in at ~260 miles a full charge, but I agree with Zbane - there are way too many factors that effect full charge, speed, weather, pre-conditioning, heat, cold, tire pressure, headwinds, weigh in the car, bike rack, rim size, tire brand, rain, software update of the week etc.

The car constantly tries to gauge your driving style and frankly a 6 mile difference doesn't mean anything - too many people get hung up on it on these forums - drive the car and enjoy it.

If I bought today I would get the 90D it sets the new standard for the new technology and the 85's will be viewed as a less premium model vs the 90. (think Mercedes E320 vs E350). If a 100D came out tomorrow I would buy that instead etc... $3500 is good insurance if you get into an extended range challenge. I think you made a good choice - early in my ownership experience I would have paid $10K more for 50 miles of range when i got caught in a blizzard with my family and could have used the extra mileage to reduce the pucker factor. I quickly learned the limits and planned accordingly. Both cars are awesome - so don't get me wrong it really comes down to your lifestyle and where you live realize some people only need a 60... Also no one drives 55 - when you are doing 80 into a headwind you are only going to get about 220 miles of range anyway...

 

I'd certainly have gotten the 90 if it was available back then. About the worst mistake you can make when purchasing an EV is to not get the largest battery available.

 

I'm not biased. I ordered the 90D battery after I've read all of these threads. I could have just as easily ordered the 85. What I'm saying is that people saying at delivery 90% charged = X range and now 90% charge = X range isn't concrete evidence of anything. Just like in ICE vehicles, fuel gauges and MPG "computations" can be widely inaccurate. A true test would be take two fully charged 90's and 85's, drive one behind the other the same speed (with enough distance between not to affect the aerodynamics of the last car) until the cars die and note the distances. Then do the same thing a month later. Relying on battery charge/range algorithm readouts wouldn't hold much weight in any scientific testing.

 

I can agree with that.

 

However, you have to do two runs. One with each car in the lead. You can't drive far enough back to not affect either aerodynamics or speed and power used. There are a number of other things to make the test really valid as well.