I'm a Tesla defender but I have to own up to this one

[lolachampcar]

yea, but get those ICE drivers to live with the car for a week (making sure they have 50 amp service in their garage) and you'll have to pry the key from their clenched fist. I've cracked my hardest nuts by simply trading cars with them for a few days

 

[Rocky_H]

Come on girls and guys.....
Sure, I understand range perfectly. I also know the number Tesla puts up on the dash for rated range is a number they choose to present.
I was so very happy when I got my first P85 and it actually did exactly what they said it would do right out of the box with the way I would normally drive a car. I did not have to go an artificially slower speed on the interstate and play rolling bollard. I did not have to accelerate like a Skoda or lift a half mile before a stop light.

The PD does not do that.

Wait. The what now? Now you're saying it's a P85D? Well that's different. Let's see the original post:

To say I was impressed with Tesla when I got my first P85 would be an understatement. Until that time, all my experience with BEVs (cars or motorcycles) led me to believe that every company on the planet was simply incapable of being truthful about actual range. That is, until I got my P85.

Apparently it was a typo, but you were going on about seeing this decrease efficiency from an older P85 to a newer P85, and that's why I was giving you an earful, because I thought you should absolutely know better, that it must be differences in driving conditions. Now that you specify that your new car is a P85D, well sure, Tesla has shown and does advertise that the P85D is less efficient.

 

[lolachampcar]

because I'm an idiot and can not type and seem incapable of proof reading......


fixed

 

[rdrcrmatt]

I've also always seen about 10% fudge factor in the numbers the car is reporting. That's why I gave up on having it show me range and just look at percentage on the dash and then use the energy consumption graphs to estimate range if needed.

Otherwise I never think about range.

 

[AB4EJ]

All the discussion about rated range has got me very curious. I live in a location where, in many directions of travel (routes I use regularly), a supercharger is something like 205 to 210 miles away. For example, I would like to go to the Chattanooga SC in a single shot - without going way out of my way to Auburn. I plan to use the Tesla to do a lot of long distance traveling. Should I plan to go with a 85D or would the 70D be sufficient? I'd like to avoid having to drive 55 mph on the interstate, and A/C is mandatory in the part of the country for > 6 months out of the year... any thoughts?

 

[Max*]

All the discussion about rated range has got me very curious. I live in a location where, in many directions of travel (routes I use regularly), a supercharger is something like 205 to 210 miles away. For example, I would like to go to the Chattanooga SC in a single shot - without going way out of my way to Auburn. I plan to use the Tesla to do a lot of long distance traveling. Should I plan to go with a 85D or would the 70D be sufficient? I'd like to avoid having to drive 55 mph on the interstate, and A/C is mandatory in the part of the country for > 6 months out of the year... any thoughts?

I'd get the 85D in your case. You're cutting it close with 210 miles in a 70D which is only rated for 240 miles. You'd also need to do a 100% charge in the 70D, and it'd take longer to get to 240 miles as compared to the 85D.

 

[lolachampcar]

I've yet to read a single regret for having too much range so I would err on the bigger battery side if I were you.

 

[dhanson865]

This is going to be the MOST confusing aspect of EV driving to former ICE drivers as EVs go mainstream... second to understanding what the heck a kW vs a kWh are and why they can't supercharge at home...

An ICE is ~30% efficient... meaning that 70% of energy is gone no matter how fast they drive or how much A/C they use. Driving 60 vs 70 in an ICE gives you <5% more range... in an EV >20% more range...

External variables like speed, A/C and topography are 30% of ICE consumption.... >80% of EV consumption... that's the 'cost' of efficiency. It's easy to forget that a P85 has the energy equivalent of a 2.5gal gas tank.

2.5 gallon? I'm not following on that comparison. Does the P85 only get 50 miles range?

check out the rated miles, mpg, and tank size of some "sports cars" and a few city cars tossed in I took from the EPA website (fueleconomy.gov).

I wondered what the least range I could find in a new vehicle was. I didn't grab every vehicle but I did search through the low MPG ones and skipped a lot of duplicates.

There must be some rounding up there or a reserve gallons not used for the EPA range not to match the highway mpg x gallons in tank but:

240 miles EPA range 2015 Dodge Viper SRT 21 mpg hwy x 16 gallon tank (21x16 = 336)
252 miles EPA range 2015 Cadillac CTS 18 mpg hwy x 18 gallon tank (18x18 = 324)
266 miles EPA range 2015 Chevrolet Camaro 18 mpg hwy x 19 gallon tank (18x19 = 342)
286 miles EPA range 2015 Lamborghini Aventador Roadster 16 mpg hwy x 23.8 gallon tank (16x23.8 = 380.8)
313 miles EPA range 2015 smart fortwo (either one) 38 mpg hwy x 8.7 gallon tank (38x8.7 = 330.6)
313 miles EPA range 2015 Chevrolet Spark 39 mpg hwy x 9.2 gallon tank (39x9.2 = 358.8)
318 miles EPA range 2015 Ferrari 458 17 mpg hwy x 22.7 gallon tank (17x22.7 = 385.9)

2.5 gallons wouldn't get a Viper SRT 40 miles let alone whatever you seem to imply the P85s range is.

 

[jerry33]

2.5 gallon? I'm not following on that comparison. Does the P85 only get 50 miles range?

The 2.5 gallons is the raw energy in the pack (e.g. the amount of fire potential). However, when you put the gas through an ICE, it's converted ~80% into heat (~60% on the best day it ever had). Because electric motors are far more efficient, you go much further.

 

[Owner]

That's quite a difference!
So in a sense, your driving a S70 range wise (not acceleration). 85 * .85% = 72

Honestly for where I live (lots of traffic), I would take range over ultra performance.

The PD is 15% less efficient than the P when people are driving around normally.
(IMO).

 

[lolachampcar]

Good point. If I drive exactly the same way, I'm very likely to go just about the same exact distance in a 70D as I do in my PD but I would likely not have as much fun Well I guess I would have exactly the same amount of fun if I drove exactly the same way in both cars.....

I have noticed that initial reasonably hard acceleration away from a light does not really hurt my W Hr/mile numbers provided I always recapture that energy slowing down (coasting a bit and never using the brakes).

 

[Andyw2100]

Just wondering, lolachampcar, if you've got range mode on or not. Because the torque sleep improvements in efficiency with range mode on are supposed to be significantly better than with range mode off.

Early on, in the winter, I was wondering if torque sleep was working on my P85D, because my efficiency, as compared to EV Trip Planner, was worse than other people's. I think the bottom line is that at some power requirement, torque sleep just doesn't kick in, so for me, in the winter, with the cold, thick air, trips at 65 and 70 MPH were above that threshold all the time.

Now we're actually beating EV Trip Planner numbers pretty consistently. I've been tracking one set of trips regularly. These trips are about half highway and half rural country road, through some towns, etc. My wife drives at least two if not three times as many of these as I do. She sets the TACC to 68 on the highway, and probably never exceeds 70. I set the TACC to 70, and will occasionally do 75 or even a little faster to pass someone and get back out of the way of someone trying to pass me. But the vast majority of the highway driving is at 68-70, and that makes up more than half of all the driving time, with the other half being a mix that probably averages about 45 MPH overall. All that being said, including some bad weather (rain, fog, etc.) that definitely hurt efficiency we're now averaging about 285 Wh/mi, when we were easily 100 Wh/mi higher than that when it was really cold. Again, some of that is, of course, attributed to the cold directly. But I think some of it is due to torque sleep working now, when it wasn't working at the same speeds in the thicker air.

I really should do another side by side at night (no traffic) with the cruise at 78 with normal acceleration and such.

If you do, and if you can stomach it, it would be interesting to see what would happen if you also did one at, say, 68. If I'm correct, the P85D's efficiency will be significantly closer to the P85 at 68 than it is at 78 because I think at 78 you are above the torque sleep threshold, and torque sleep is just not kicking in. Since you drive at a higher speed than I do, this would explain why you're still seeing Wh/mi consistently above 300 and I'm (well, we're--me and my wife) are now seeing Wh/mi consistently below 300.

 

[Ben W]

Really, I'd like there to be this and a fourth setting to the Rated/Ideal miles display. The last one being "Custom" where I can select my own Wh/mi for a mile displayed.

Or perhaps ‘Sport’ = 350Wh/mi? (Or perhaps also ‘Insane’ = 400Wh/mi)? I’d appreciate having the option to customize, too. Of course, Tesla doesn’t want to officially “admit” that anyone is consistently getting worse efficiency than the EPA states, so they'll always want the highest number on the dash (rated miles of charge remaining) as possible. That’s probably why they haven’t allowed customization yet. You just know some half-assed “reviewer" would crank it up to 600Wh/mi and then publish a screenshot saying “Haha, full battery, only 141 miles!! Tesla admits it!” For the same reason, many ICE cars show projected range remaining, but none of them (to my knowledge) allow the MPG settings to be customized. It’s always the EPA rating.

My lifetime average (after 29k miles) now stands at 353Wh/mi, and it’s lately been sort of a game to try to reduce this to 350Wh/mi. I regularly drive between LA and Santa Barbara, and it’s also a game with myself to try to do this trip as efficiently as possible, without going artificially slow. My best so far is 286Wh/mi. (in a P85 with 21” rims.)

[Updated for correctness]: FWIW, “Rated” for the P85 is 306Wh/mi (= 81.1 kWh / 265mi), and for the past 5k miles I’ve averaged 335Wh/mi, or about 91% of rated performance. Considering that the EPA rating is rather conservative, I’m quite happy with these numbers. Also note that displayed “Rated” miles decrease by 1 for each 286Wh used, to provide the 5kWh buffer zone below “0 miles”. The 3.9kWh difference between 81.1 and 85 is the “bricking” protection buffer at the bottom of the pack, which can’t be used for driving.

 

[lolachampcar]

Andy,

There are a bunch of ways I can manage consumption but that was really not my focus with this post.

My interest was in what Tesla tells us about capability. In an ideal world, Tesla would adjust the displayed range charge rated miles such that any two cars (with the same size battery is a similar state of degradation) would produce roughly the same rated mile consumption for a given trip. There will always be slight differences as one model may do better in stop and go while another does better on the highway and such.

In this instance, it feels to me like Tesla has placed a SLIGHTLY artificially high displayed range charge rated miles on my PD. Using the PD, I get about 91% of the miles I got with my P and my P+. This is already starting out with a rated range adjustment from the PD at 254 while the P and P+ started out about 265. I've got enough miles under my belt and very good repeatability with consumption to be pretty confident that it is not driving style or conditions on a given day driving the distance.

 

[Andyw2100]

Andy,

There are a bunch of ways I can manage consumption but that was really not my focus with this post.

My interest was in what Tesla tells us about capability. In an ideal world, Tesla would adjust the displayed range charge rated miles such that any two cars (with the same size battery is a similar state of degradation) would produce roughly the same rated mile consumption for a given trip. There will always be slight differences as one model may do better in stop and go while another does better on the highway and such.

In this instance, it feels to me like Tesla has placed a SLIGHTLY artificially high displayed range charge rated miles on my PD. Using the PD, I get about 91% of the miles I got with my P and my P+. This is already starting out with a rated range adjustment from the PD at 254 while the P and P+ started out about 265. I've got enough miles under my belt and very good repeatability with consumption to be pretty confident that it is not driving style or conditions on a given day driving the distance.

I agree 100% with the principle that you are demonstrating. I am one of the people who feel just slightly misled by the original efficiency claims. I am most definitely on the same side as you in this.

I'm just pointing out that Tesla's efficiency estimates for the P85D --did-- include torque sleep, and after we purchased the cars we discovered they hadn't released it yet. When they eventually did, we learned that to get the full benefits, we need to use range mode.

Don't get me wrong--I would love it if Tesla separated torque sleep from range mode, and have posted messages to that effect many times. But for now we know that to even attempt to come close to the originally promised range, we need to fully enable torque sleep, and to do that, at least for now, we have to have range mode on.

My point is that to do any comparison involving P85D efficiency, while not allowing it to utilize torque sleep to its full capabilities isn't really a fair comparison, since a big reason the P85D was supposed to be as efficient as a single motor Model S was its ability to sleep one of the motors when it wasn't needed.

 

[Rocky_H]

FWIW, “Rated” for the P85 is 321Wh/mi (= 85 kWh / 265mi), and for the past 5k miles I’ve averaged 335Wh/mi, or about 96% of rated performance. Considering that the EPA rating is still rather conservative, I’m actually quite pleased with these numbers!

Please, don't go telling those kinds of incorrect things. We do NOT have access to the complete 85kwh of the battery for driving range. There are several kwh reserved at the bottom of the battery level (sometimes referred to as anti-bricking protection) that Tesla keeps us from accessing so we do not damage the battery packs. The car will shut down with those kwh of charge remaining to protect us from messing that up. So the rated value for the S85/P85 variants of the car is not 321. It's a little under 300. That has been confirmed by many people. I saw a guy here on the forums taking his highway wh/mile that he can usually get and multiplying it out by 85kwh, thinking he could drive all the way from Tremonton to Boise straight through, and I had to warn him that he was very likely going to come up short, because of not actually having 85kwh to work with.

 

[AB4EJ]

I'd get the 85D in your case. You're cutting it close with 210 miles in a 70D which is only rated for 240 miles. You'd also need to do a 100% charge in the 70D, and it'd take longer to get to 240 miles as compared to the 85D.

I've yet to read a single regret for having too much range so I would err on the bigger battery side if I were you.

Yes, I believe both comments are quite right. Also, one has to think about the future - batteries do lose capacity over time. My tendency is to keep a car that I like for a long time (typ. > 10 years), so the higher capacity would seem to be a necessity. Also, in the deep south, one has to use A/C a lot, and you have to set aside capacity for that as well.

 

[sorka]

Lola, I assume you have the stock 19" wheels or upgraded 19" cyclones? Anything else and all bets are off especially if you have an after market wheel which most don't so I assume you don't either.

The 254 rated range is only for the 19" wheel. 6% less for the 21" wheels. 3% more for the 19" cyclones.

So the only thing I have for comparison is the p85+ loaner I had for a week. I average the same or a little worse than my p85d under the same temperatures and routes. It had 21" wheels though, so I imagine with 19" wheels the P85+ would have done better.

That said, my commute is 256 miles round trip, I had been getting in the low 280s at 65-70, but in the last month have been driving more like 70-75 and that average has climbed to about 305 wh / mile. But surely the epa rating doesn't include driving as fast as I drive now.

Ironically, the new tesla range tool now puts the p85d at the same 285 miles of range as the S85 at 65 mph with no ac and 19" wheels on both which is even more optimistic than the old range tool.

BTW, 319 wh / mile would get you 254 miles before the car actually died assuming zero battery degradation and you used up all of the zero mile buffer. i.e 85 - 3.9(anti brick buffer)

 

[AB4EJ]

The 2.5 gallons is the raw energy in the pack (e.g. the amount of fire potential). However, when you put the gas through an ICE, it's converted ~80% into heat (~60% on the best day it ever had). Because electric motors are far more efficient, you go much further.

When I read the 2.5 gallons, I thought of it in terms of the "equivalent miles per gallon." According to the Tesla website (not sure if this is completely objective, but anyway) MS gets MPGE 138.5. So 2.5 gallons X 138.5 = 346. Actually the MS may have a lesser equivalent, in that if the 138.5 MPGE is right, its actual range of 270 would suggest a gas tank equivalent of 1.9 gallons. See http://my.teslamotors.com/forum/forums/tesla-model-s-mpg-equivalant [sic] - assuming you could get the entire 270 miles out of a full charge (should be possible depending on speed - that's a big wild card).

 

[lolachampcar]

andy,
Good point!