Tesla electric estimator lies by a factor of 2!

Tesla electric estimator lies by a factor of 2!

So, bought a Model S the last day of the year due to tax credit scare. I don't drive very much, but put in the WORST case scenario. I plugged in the coldest temperature, 70mph (I never go above 50), and heat on. It said I should use about $30 or something much lower than my ICE car which got 20 mpg and I spent $50/month on gas for. So I thought great, I am saving $20/month. WELL my DTE Electric bill just came and it was exactly $100 over any month I have ever had. $100 over last month and $100 over January 2016,2017. So, estimator said would cost me $30 in electric and it ended up costing me $100 in electric, which is $50 MORE per month than my old gas car. I realize in the summer in Michigan it won't have to constantly heat up the battery 24/7, but seriously, my car is garaged and paying twice the price of gas is ridiculous. Tesla needs to update the website to show REAL range and REAL electric use, not pull numbers out of their @ss. And yes I knew my bill would be a little higher than their estimate since I pay .15c/kwh and the estimator is at .12c/kwh, but STILL that is NOT DOUBLE.
Tesla, get your act together already, seriously, for an $80k car, their should not be all these build and quality control issues where a ranger has to come out every month for a new car, the battery range should be real, not over inflated, and same with the savings calculator over gas.
After the cool, I bought a Tesla factor wears off, I am realizing I could have got an AMAZING ICE car for $80k with no build quality issues and paying less for fuel. They should really have to disclose that you will eat electricity like crazy in northern states and that you also are going to have to pay $1200 for Opti-Coat or some product to fix their 3 H hardness paint, which is soft and the worst paint since the 1970's. Sorry about the rant, I do like the car, but it is NOTHING like they promised. I shouldn't be surprised though as Elon ALWAYS overpromises everything.

carlk | February 8, 2018

What are you talking about? My 14' S and 16' X all have very great build quality. What I heard is latest ones are even better.

Should_I | February 8, 2018

This will vary dramatically based not only on climate but the length of your drive, too hard to make a calculator.

The electricity price is 25% of your issue, no small thing, and is actually the price I pay for electricity so it is a valid number.

I would hope people capable of spending $80k on a car are capable of doing basic research, but sadly that all too often is not the case.

I have a short commute and the car is parked outside, here in Wisconsin it was -4f this morning, yes the car can use double miles+ if I leave with a cold battery and for me with a very short commute that happens a LOT because driving I never warm up the battery fully. I understand that and in fair weather it uses a lot less energy.

PBEndo | February 8, 2018

Also, the efficiency of different charging sources varies dramatically. In general, the weaker the source, the slower the charge and the higher the wasted energy.
Charging from a 110v outlet is not only slow but is very inefficient.

PBEndo | February 8, 2018

So, with gas averaging $2.5 and you spending $50/month to drive a 20mpg car, you only drive 400 miles per month and your electric bill went up $100?

I live in Florida so my climate is better and the electric rate is closer to $0.09/kWh, but I drive almost 5 times as many miles as you and I never drive under 50mph and my electric bill went up less than $100/month

tes-s | February 8, 2018

When you got your S, did your wife also get an electric toy? Perhaps she is putting on more miles than you think.

PBEndo | February 8, 2018

Though I don't think you were asking me, when I got my second S my wife did get an electric toy. My first S hand-me-down. Combined the electric bill barely increased $100.

SbMD | February 8, 2018

@Criag1965 - you should really do a more in depth analysis if you want to understand your Tesla's electricity costs to you:
- cost of electricity in the comparison months (it is NOT the same month-to-month in many places)
- electricity consumption the analogous months prior to owning your Tesla
- electricity consumption the months where you owned a Tesla
- account for "other" or "primary" consumption (i.e. other electric appliances including heat/AC)
- check if you have a Michigan Smart Meter and when it was installed, and if it is consuming energy in transmission as well as properly calibrated
- take into account how much do you drive per day and more important, how much energy you consume and need to recharge per day or week

Until you look at these variables and a few others, you really cannot attribute your electric bill differences to your car.

For comparison, my electricity costs are more than yours, it appears, my car is my daily driver so it gets "used" and my "fuel" costs plummeted by no longer driving my ICE. I was spending around $100/month on gas. My findings are not unique.

Translated: your analysis is incomplete and likely incorrect.

Bighorn | February 8, 2018

What are your thoughts on global warming?

Craig1965 | February 8, 2018

Well let's just say the 100mpg equivalent is 50mpg at best in winter. I realize summer will be much better, but I also just switch to lower rate from 7pm to 11am, so can charge cheaper overnight. But in Summer the houses AC running from 11am to 7pm at double electric rate will end up costing me more most likely. I do drive almost all short trips, like 5 to 10 miles twice/day. Also as far as build quality, my doors have like an inch gap on one of them, 1/2 inch on the others, molding off center, windows leaking requiring rubber replaced, paint scratched and marred the first 2 weeks looking worse then 4 year old Acura black paint, charge port where you need to be Arnold Schwazzenegger and make 37 attempts to plug it in and get it charging (ranger is coming out tomorrow to replace that). Bottom line is before these cars leave the factory, NOBODY is doing an even remotely good job at quality control. I mean I read an article saying the quality control is same as a 1990's Kia, and that is total sh!T. Don't ship the car if it isn't DONE, DUH!

PBEndo | February 8, 2018

An inch sized gap on the door?
Perhaps you (like many men) underestimate the actual size of an inch.

tom168 | February 8, 2018

Hmm. We have a very unhappy customer here. His electric bill has gone up by $100, which is $50 higher than his old gas bill. $50 @$3.00 / Gal, say 17 gal , Say 20 miles per gal = 340 miles per month. A typical Model S uses 300 to 400 wh per mile. That is, 2.5 to 3.3 miles per KWH. So, he uses between 103 and 136 KWH for a month to charge the car. $100 means $0.73 to $0.97 per KWH. Please ask your electric company to check your meter.

Granted the 2017 year end Model S has Charge port connection issue. I hope the problem is fixed.

Hope all your issues are taking care of. Most of the folks in this forum have their good and bad experience with the car. At the end, we become happy customers. Hope you'll become one of us soon.

T34Bravo | February 8, 2018

This post is making my BS meter go off by a factor of 2.

Craig1965 | February 8, 2018

tom168, I drive with a light pedal and 45 mph to work, I'm getting like 600 wh per mile. It is obviously because I have the heater on 72 F and it is 20F outside. No B.S., I literally am getting half the estimated range between pre-heating the car 10 minutes and driving 15 minutes to work. I know better weather will improve this, but no one at the dealership said anything but, "It is AWD, heavy, low cg, and GREAT in the winter." They never said the heater stays on 24/7 to heat the batteries when not in use. It is a great car, but great for southern states, northern states, uh, not so much. And the door gap is from inside the car. Sit in the drivers seat and look at the front passenger seat door when closed, there is a 1 inch gap, the other doors are about 1/2-3/4 inches. The ranger said the door was off by more then he could fix and will have the Tesla approved body shop align the door. You guys can have blinders on if you got a perfect car delivered, but there are tons of studies showing that Toyota's come thru quality control with like 98% of them passing and Tesla is about 20%, that is pretty lame.

Mi75d | February 8, 2018

Yup, using a Tesla Model S for short distances, then letting it sit in the cold is the worst case scenario for Tesla mileage.

OTOH, my wife and I just completed a vacation drive of 1,800 miles. Total cost - $0.00 thanks to free Supercharging. You've got to put that against the cost of electricity at home. That's a $250 savings on gas right there.

djlott | February 8, 2018

Did you seriously buy a Tesla Model S with the idea of saving money on your electric bill? Sorry OP but your OP is ridiculous. You should have purchased an amazing used Prius. I understand the rant factor here but your expectations are off the chart. My electric bill went up $50 per month with Model S charging after hours at .12c/KWh with a 52 mile daily round trip commute in CA. Sorry I just don't think this is real. Pics of the 1 inch gap in the door please?

Bighorn | February 8, 2018

Battery heater does not stay on 24/7. In range mode it doesn’t even come on. Of course short hops are going to be inefficient if you heat the car fully every time. Science will trump fake news.

sr.smr | February 8, 2018

I have a time-of-use meter that provides lower rates from midnight to eight a.m. that I use to reduce costs. But the bottom line for me was not the cost of charging the car, but all of the high tech toys that come with the car. I'll give you that it doesn't have the best frequency of repair record, but the car eventually gets to its peak performance after the bugs are ironed out and then you have the quietest, fastest, feature laden futuristic car on the market. Half the service calls were performed by a rover so it saved me the inconvenience of driving to the service center, and the other SC repairs were repaired as expected by courteous and professional staff.

I know its frustrating in the beginning as I hear what you are experiencing, but I'm telling you it will be worth it at the end. I also know there are ICE cars out there that are feature laden, but they can't drive themselves, you need a magnifying glass to view the navigation map, you can't breath when your pulling out of an enclosed garage, you have to wait to get heat, overall maintenance cost are higher, and these are just the top of the list negatives I can come up with.

NKYTA | February 8, 2018

Well, at least you didn’t say a 100k car.

I’m actually proud that I bought a 92k car, five years go.

NKYTA | February 8, 2018

BH, excellent turn of phrase!

s.grot | February 9, 2018

So for $100/month at 15 cents /kwhr gives you 666 kWhrs. Even at 600 wh/mile gives you 1110 miles per month. He says he drives 45 mph for 15 mins every day that’s 12 miles a day or 360 miles a month. So his fake news just doesn’t add up.

Maybe he is leaving his heater on when he exits vehicle , and it runs all night

Anthony J. Parisio | February 9, 2018

First of all make sure your heat is not set to always on.

Secondly assuming your heat is not always on, it takes longer that 10 mins. to heat a cold battery. On the dash in front of the drive you can pull up the power usage gauge. If there are dotted yellow lines and your regen. braking is limited your battery is cold. In this state the Battery heater which uses a huge amount of power is on. In your case it will stay on through your whole drive. Tesla's electric estimator does not include this circumstance. That is why the numbers are way off for you. Short drives in Winter with a cold battery is the electric cars short coming. I'm sure you will be surprised at your savings come Summer.

As for you fit and finish problems, I'm sorry to hear about this. My car was perfect. 2017 S 90 D. I hope you give Tesla a chance to address the issues.

Tesltoronto | February 9, 2018

Craig1965 - I drive about 80 miles per day. My electricity bill has gone up by about $50 per month (the electricity price is about 12 cents per KW here. Your math does not add up or you are doing something wrong.

This is my second Tesla and have beein driving one since 2014.

amareshvanga | February 9, 2018

Tesla is very inefficient in cold weather as there is some daily vampire losses plus double the energy usage in real life situation on my drive.
But I brought tesla for its tech and performance and how cool it looks.Not so much for mileage.if I was concerned about mileage then I would have got pruis
the calculator on tesla website overestimates the range especially when weather is chilly and cold.

RedJ | February 9, 2018

Another possible contributing factor is regenerative braking. Having it set to low will limit energy recovery which will have a particular effect on non-freeway driving.

Craig1965 | February 9, 2018

Bighorn, when you live in a northern state and the temp in your garage is 10-32F, then yes, the car needs to heat the battery 24/7. Don't get me wrong, I love the car, but it does have issues, and is really more of a southern weather car, at least until battery tech can be improved in cold weather.

Craig1965 | February 9, 2018

djlott, sure, here is a picture of the door gap AFTER it was fixed as best as ranger could do, then he said it would be best to have the body shop do it. Two pics here imgur(dotcom)/a/6vUyi make the (dotcom) into proper link phrasing, wouldn't post normally.

Craig1965 | February 9, 2018

My numbers are not fake and the heat is not always on. I usually pre-heat the car/battery for about 10 minutes to 70F before I leave, so I do have regen braking. As soon as I get in the car it tells me I am at like 1100 kw/mi or whatever since I haven't driven yet, only pre-heated the car and wasted a lot of electricity, then 15 minutes later when I get to work (7.5 miles), it goes from 150 miles to 125 miles left and I used about 550 kw/mi for the trip. I do not drive fast or have it set to slow range mode. I also will not drive to work freezing, so the car like any normal car is set to 70-72F. My main loss is coming from the 10 min pre-heating the car as well as the other 24 hours of the day that it is heating the battery pack constantly. The car loses about 2 miles per hour sitting outside at work in the cold because it is heating the battery pack and not plugged in. I know A LOT about LiPo batteries and care of them since I have been an RC pilot for 10 years, but I have never had to heat them. Obviously Tesla heats them to keep them at ideal temps to last thru the 8 year warranty. Now I am curious to at what temps does the battery heater come on and what temps does the battery AC cooler come on in the summer, since it can get to 95F in Michigan summers as well. Does anyone know the temps that their is NO extra battery heating or cooling done at? I'm guessing 40F-80F based on my battery knowledge, but the exact numbers would be nice to know. I guess on the bright side of things is Spring and Fall will use a lot less electricity. I'm starting to think the 10 minute warm up to get regen wastes a lot of electricity and maybe it is better to skip it, just do 2 minutes to warm up the cabin, and drive. Sure I lose regen for a few minutes, but regen doesn't happen that much or save that much electric. Any ideas on optimum pre-heating time to save electric and exactly what temps battery gets heated or cooled at wasting all that electricity?

JaMo_75D | February 9, 2018

Yup thats why I would never live in the north....the cold sucks. Dont forget that cold weather affects mpg/fuel economy in ICE cars too.... If you want a fair comparison you have to factor that in as well

Craig1965 | February 9, 2018

Eh, my ICE car Acura TL AWD got 20 mpg city whether hot or cold. AC or Heater wouldn't change it significantly, worst I ever got per tank was 19 mpg, best ever was 21 mpg. Nothing like the 50-100% difference in Tesla's range/electric use depending on outside temps.

reed_lewis | February 9, 2018

Comparing your Tesla to RC batteries makes no sense because you most likely do not leave your RC batteries out in the cold all the time. OTOH, your Tesla is left in the cold.

I live in cold New England, and even during the very cold snap, I used less than 400 Wh/mile for my commute to work (about 38 miles). Of course, I preheat the car for about 30 minutes to truly warm it up. Warming it for 10 minutes will not warm anything.

My average Wh/mile for the last 6000 miles (it was reset on the last service) which pretty much is the worst of winter is 356 Wh/mile. In the summer, I average about 280 Wh/mile.

My thought on electricity usage is that even if I preheat for a full hour, that is about 4 kW for an hour with is 4 kWh of electricity which costs 40 cents for me. (I happen to pay about 9.8 cents per kWh).

Also did you compare kWh used this year versus last year? Is there anything different in your house that might be using more power? Personally, I have two EVs (ModelS and Chevy Volt), and our electric bill has not changed noticeably.

PatientFool | February 9, 2018

@Craig1965 can you PLEASE stop being so melodramatic and please for the love of god use paragraphs? Folks will be far more helpful..

Bighorn | February 9, 2018

I live in the mountains of Wyoming, so am familiar with the last 5 winters’ effects on the battery. 10 minutes of battery preheating consumes 1 kWh. Were you to pre-warm the cabin on an ICE car, you’d spend more $ in gasoline to bring the engine to temperature. Conventional wisdom for years has been to not let cars warm up, so you end up driving a cold car for short commutes such as yours. I’ve seen no evidence that the battery warmer comes on in a parked car and I’ve done trips where I’m in the car 24/7 for many days straight. Tesla acknowledges that fewer miles will be available if the battery gets cold. There’s a visual warning if you arrive under a certain SOC. As you note, battery heating wastes energy which is why some opt to use timed charging to achieve a degree of battery warming. Seeing 1100 Wh/m for the first few tenths of a mile is an artifact of a small denominator with no significance. I once saw over 8000 Wh/m when I’d idled the car with the AC on for a couple minutes—it quickly reverts to the mean. With temps in the 20s-30s, if I pre-warm the car/battery, I can achieve efficiencies similar to summer driving which in my case is under 200Wh/m since my 10 mile drive drops 400 feet. Please stop spewing BS out of ignorance and seek guidance from people who have a shiton of experience and recognize the folly of your blather.

ktslab | February 9, 2018

You pay $80K to $100K for a model S to enjoy the car. To purchase the car for the main reason of that "I will save fuel cost compared to ICE is a mistake".

when you can afford $80 ~ 100K car, the fuel consumption should be the least of your concern. At least for me, it isn't. I want a cool car so I bought the MS. The environmental benefit, fuel savings, are just a side benefit that I know about but don't care too much about. Call me ignorant, the feel-good factor related to fuel and environment is not appealing to me.

My MS is garaged and I live in New England. It does suck up more electricity in the cost winter than I anticipated. A little disappointed? yes. Do I want to do something about it, hell no. Man, I love the car.

Craig1965 | February 9, 2018

Bighorn, so you are saying that overnight when it is 20F out, whether the car is plugged in or not, the car will not use any energy to warm up the battery pack? I was under the understanding that in extreme temperatures it does that to prevent any damage to the battery. We even get 0F days, and I have heard that in say Arizona when a parked car can be 110F that the battery will need to cool itself. All this makes sense, but if what I heard is incorrect and it never uses electric to heat or chill the battery when parked, then please correct me or point me to a place where Tesla states at what temperatures parked does the car use electric to chill or heat the battery or not. Thanks, and thanks for the advice not to pre-heat the car 10 minutes for short drives, some people (and Tesla) told me 20 minutes! I pay 16 c/kwh so pre-heating for 10 minutes would cost me close to $1 every day, that is the difference, I will pre-heat 2 minutes just to warm the cabin and due without regen the first few miles.

ktslab | February 9, 2018

can't spell "cost winter" = "cold winter"

txakoli | February 9, 2018


Is Smart Preconditioning set to "ON"? If it is, set it to "OFF" and precondition the car with the app. If you have an irregular driving schedule, Smart Preconditioning may be heating the car at odd hours.

Captain_Zap | February 9, 2018

Criminy sakes! Where to start??

Craig1965 | February 9, 2018

ktslab, Yeah I agree with you but I am not rich. I didn't even want the car till Spring, because why buy it in December and drive thru a winter and get a model branded 2017 instead of 2018, but the tax law scare of losing the $7500 credit forced me to buy the pure base 75D December 29th because I could only afford the base model if I got the credit. I am sure my experience would have been better in the Spring, and I do love the car, but I was also using their online gas savings calculator to help justify the cost of it. And going from ICE at 20 mpg to a 100 mpg (CLAIMED) would be a huge savings and allowed me to purchase it. Well it is really going from 20 mpg to about 50 mpg equivalent, so that is my gripe, and as I said I set the estimator on the worst case options, coldest outside, fastest speed, heater on and it overestimated the range by 2X, that is just innacurate and misleading. Why have a calculator where you can put in your outside temp, speed driven, and heat/ac on if it is just going to spit out a completely wrong number off by 100%? They need to fix their website, which was the whole point of the OP, not to bitch about the car. I like the car. The only things I don't like about it are well documented all over these forums (poor build quality, soft paint requiring $1200 ceramic coating or $3500 wraps, and of course the wrong energy estimations)

Craig1965 | February 9, 2018

Smart preconditioning is off because I don't leave for work the same time everyday, or work everyday, I use the android app to warm it up 10 min before I leave, now I will just warm it 2 min. I type real fast, so sorry if there are some misspells or paragraph issues for the grammar police, lol

NKYTA | February 9, 2018

BH took a long time to get to the point. Such patience.

Nailed it with the last sentence though.

ktslab | February 9, 2018

@Caraig1965, I feel you. Just that maybe I was able to cope with this better. lol

Bighorn | February 9, 2018

Like I said, 10 minutes if battery preheating consumes 1 kWh, so 13 cents, not “close to a dollar.” Granted the cabin heating can cost as much if you make it a sauna, but that’s under your control.

I’ve not heard of battery heating coming on ever, but it was suggested that it may happen at about -25F which is around the temperature Tesla says not to expose your car for more than 24 hours. I think you are confusing cabin overheat protection with battery cooling. The AC is triggered to prevent the cabin from getting too far into triple digits in order to protect any inadvertent occupants. This is an option you can turn off.

Also my build quality is excellent and the paint still looks new after 172k miles. Plenty of folks haven’t sprung for aftermarket protection and have done just fine with routine waxing. Lots of negativity based on internet folklore is what I’m gathering from your comments.

If you are truly nickel and diming your 10 mile commute, don’t pre warm the cabin, wear a coat and use seat heat. Turn on range mode to disable battery heating. You’ll look like everyone else doing their morning commute in their icy ICEs.

Bighorn | February 9, 2018

When in Rome... :)

lilbean | February 9, 2018


Craig1965 | February 9, 2018

I had a remote starter for my ICE car, so never got into a cold car. Using the seat heater is fine for your butt, but your hands and face are freezing, so you need cabin heat like an ICE car. I didn't know that setting range mode disables battery heating, but I am going to leave it at normal because I don't want a slow car or more importantly I want the battery life to be maximum, which means you should let it heat the battery when needed. I found this page VERY informing about the fact that at certain temperatures the car does heat or cool the battery whether plugged in or not, just as I thought, to protect the battery's life. I'm not going to be so cheap to drive freezing, and the extra $50/month in winter isn't going to kill me, but the fact is it still is double their estimator cost, which to me is not a margin of error of say 10%, it is 100% difference, so they need to fix the website estimator. | February 9, 2018

I'll only chime in on the "soft paint" comment. It's a scam that some coating companies claim for any car you bring in so that they can soak you for $1000+. I'm not saying the coating have zero value, but the paint and clear-coat that Tesla uses is the same paint that other higher-end cars use. Tesla's paint is not any softer or harder than anyone else. Unscrupulous companies tell this lie to get people buying their overpriced products. Now those coating are nice, and perhaps a bit harder than a wax finish and should last longer. But too many fall for the soft paint lie. These companies really should sell their coatings on its merits, and not lie to trick people.

reed_lewis | February 9, 2018

I have had many cars over the years, and the Tesla paint is just as good as any of the other cars I have had. I just wax it on a regular basis, and nothing else.

I take it through a car wash every few days (more so if it is covered in salt,etc.). The finish still looks new. I would never get my car 'wrapped' or anything of the like.

reed_lewis | February 9, 2018

...And @Craig1965, since you used a remote starter, you obviously consumed gasoline to warm the car up. That will not be reflected in the MPG gauge of the car because you are not travelling. The car will only report that MPG when you are moving. So you have another amount of gas used which you paid for which you are not accounting for.

tes-s | February 9, 2018

"I had a remote starter for my ICE car, so never got into a cold car."

Then you were spending more money on gasoline warming the ICE than it costs in electricity to warm the Tesla.