Tesla Range - Surely there’s something wrong?!?

[LukeUK]

Lots of people talk about the benefits of preheating or preconditioning before you set off as a way of boosting efficiency.

I agree with you. It doesn't boost efficiency, when you consider the energy used for pre-heating as part of the total energy used for the journey. It does boost range, and also improves drivability, as you will get more regen, sooner.

It may also not be cost effective to pre-heat on mains. I use Octopus Go. If I don't need the range, I will pre-heat the car using the battery on a cold morning, as the battery was charged using cheap electricity over night. If I plug it in to preheat, I'm using electricity that costs ~3x as much - not cost effective at all.

If I need to do a long journey in the cold, I would probably pre-heat on mains, and it's then still cheaper than supercharging or using 3rd party chargers.

 

[Adopado]

Lots of people talk about the benefits of preheating or preconditioning before you set off as a way of boosting efficiency. Maybe I am being stupid, but can someone please explain to me how using electricity from the mains to heat the car/battery help with efficiency?

It's not more efficient overall. In fact for many of us daytime electricity is more expensive so it costs a bit more too ... but it's only pennies. If you are plugged into shore power it simply saves "wasting" potential battery range heating up the battery and cabin. Your journey will have more battery capacity available so you will have slightly increased range.

 

[DJP31]

One of the top reasons people buy a Tesla is for the battery range. Would you be happy buying a 50k car (price doesn’t really matter here though) quoting 360 miles of range but instead gave 50 miles just because your daily commute is 10 miles and you can charge at home? (Exaggerating the circumstances of course).

It’s funny but I don’t think anyone commenting has said maybe the battery could be the problem. I don’t know if that is an issue anyone else has had but logically could occur? Too early to tell yet.

Yesterday's data from TeslaFi. Commute to work, home for lunch, back again for the afternoon and home again. 4 miles each way.

4 Drives
Total Miles Driven 16.82
Rated Miles Used 30.86
Efficiency 54.5 %
Time Driven 58 Minutes
Wh/Mile 459 Wh


On the basis of this my £90k (mentioned only as you quote it) MS LR with nigh on 100kWh usable battery has a range of about 50% what it should do and is not fit for purpose. Who cares as it was 4 short journeys and as we know, efficiency improves the longer the drive.

Compare the above to this, in early September:

Total Miles Driven 94.06
Rated Miles Used 94.46
Efficiency 99.58 %
Time Driven 2 Hours 44 Minutes
Wh/Mile 246 Wh

No-one has commented on whether the battery could be a problem, because IMO on-one believes it is.

Your car is fine, switch to % and use the energy graph when on a journey where range is a factor

 

[MrBadger]

Our real world driving efficiency over 16 months and ~8k miles. We only pre heat when chance of freezing.

First one is journeys > 10 miles. Second one includes the previous daily commute of ~6 miles each journey which would have been concentrated over the cooler months last year.

 

[LukeUK]

Similar picture yesterday, M3LR. I went to pick up tea.

To extrapolate based on this data, the car has a range of below 150 miles. But it doesn't.

 

[DJP31]

It's not more efficient overall. In fact for many of us daytime electricity is more expensive so it costs a bit more too ... but it's only pennies. If you are plugged into shore power it simply saves "wasting" potential battery range heating up the battery and cabin. Your journey will have more battery capacity available so you will have slightly increased range.

Given the shortness of journeys at the moment I don't plug in more than once a week, but still pre-condition before every journey. I'm using the car's energy source to do this but as I'm recharging using off peak and daily range doesn't matter I've no worries, and am not using shore based leccy when it's more expensive.

 

[Rooster6655]

Everyone drives differently so there will of course be some variation but if I still get less than 150 miles on warmer days and slightly longer commutes added in, then I think there is an issue.

On warmer days I would expect to get 250-270 in summer and 180- 200 in winter, so it doesn't look like a problem to me.

 

[MrBadger]

For those with TeslaFi, I just noticed this new TeslaFi feature - only works since last charge though and not on prior charges that I can see. Not so useful if you do a top up and don't drive anywhere.

Worth pointing out the use of the likes of TeslaFi (SaaS) and TeslaMate (self hosted) when trying to understand where their range goes.

 

[TiLaSoul]

Lots of people talk about the benefits of preheating or preconditioning before you set off as a way of boosting efficiency. Maybe I am being stupid, but can someone please explain to me how using electricity from the mains to heat the car/battery help with efficiency? You are still using energy to do this, even if it’s not coming off your state of charge (you are charging the car to provide the electricity to heat your car before you drive it) I guess it might be more efficient to pre-heat the battery at home, rather than allowing it to get up to temperature while driving? But it really just spoofs the cars actual efficiency and seems to be more of an exercise in delusion.

At the moment I can’t help but think this is the equivalent of starting a little fire under the engine of your ICE car before setting out, to get the engine to its optimal operating temperature. And then completely ignoring the energy used!

I don’t think anyone is ignoring the energy used but OP is complaining about range. It’s indisputable that pre-conditioning improves range.

Pre-conditioning, even for short journeys, still makes a difference and costs less than equivalent ICE journeys.

 

[Glan gluaisne]

Arguably, pre-conditioning whilst plugged in for short journeys has a very much more beneficial impact on battery range than it does on longer trips. Short trips in cold weather really hammer efficiency, without plugged in preheating, it seems.

 

[LukeUK]

For those with TeslaFi, I just noticed this new TeslaFi feature - only works since last charge though and not on prior charges that I can see. Not so useful if you do a top up and don't drive anywhere.

Worth pointing out the use of the likes of TeslaFi (SaaS) and TeslaMate (self hosted) when trying to understand where their range goes.

View attachment 628023

Noticed this as well.

 

[Kenners]

I agree with you. It doesn't boost efficiency, when you consider the energy used for pre-heating as part of the total energy used for the journey. It does boost range, and also improves drivability, as you will get more regen, sooner.

It may also not be cost effective to pre-heat on mains. I use Octopus Go. If I don't need the range, I will pre-heat the car using the battery on a cold morning, as the battery was charged using cheap electricity over night. If I plug it in to preheat, I'm using electricity that costs ~3x as much - not cost effective at all.

If I need to do a long journey in the cold, I would probably pre-heat on mains, and it's then still cheaper than supercharging or using 3rd party chargers.

Octopus Go too.

I was wondering if you pre-heat on battery before you go out does that boost overall efficiency, do you actually get a better range than if you didn’t? I am assuming that energy to heat the battery when car is parked is quite a bit less than early journey and energy is being used to drive, heat up battery and regen is not as efficient.

On a ten mile journey in 5c temps am I going to use more energy preheating in battery first than if I just got in and drove there, that is not clear to me.

 

[Glan gluaisne]

Octopus Go too.

I was wondering if you pre-heat on battery before you go out does that boost overall efficiency, do you actually get a better range than if you didn’t? I am assuming that energy to heat the battery when car is parked is quite a bit less than early journey and energy is being used to drive, heat up battery and regen is not as efficient.

On a ten mile journey in 5c temps am I going to use more energy preheating in battery first than if I just got in and drove there, that is not clear to me.

Pre-heating whilst plugged in makes a significant difference to energy usage for short journeys in cold weather. Last night, when it was just above freezing (+1°C) I drove to the pub and back (collecting a takeaway), a round trip of about 9 miles that will use around 2.8 to 3 kWh in warm weather, and often over 5 kWh in cold weather. I pre-heated for about 20 minutes before setting off, using around 1.8 kWh of mains electricity and the car seems to have used about 3.3 kWh. That equates to a range improvement, for a series of short trips like this made in cold weather, of over 30%, so quite significant. If extrapolated out to the typical warm weather (real world) range of the Model 3 LR of around 285 miles, then the difference for a series of cold weather short trips would seem to be an improvement from maybe 185 miles range without pre-heating from the mains to maybe 260 miles, perhaps more, with mains pre-heating.

 

[MrBadger]

How much came from the battery pre heating? 32A mains power can't cover all the pre heat power requirements. iirc pre heat peaks at 13kW power draw.

 

[Glan gluaisne]

How much came from the battery pre heating? 32A mains power can't cover all the pre heat power requirements. iirc pre heat peaks at 13kW power draw.

Not that much. The trip to the pub (which was the one from a very cold start was 4.71 miles and used 1.57 kWh, so about 333 Wh/mile. It's hard to be sure exactly how much battery power was used during the preheating period from the data display, but it looks as if it was probably about 0.3 kWh at the most, so the true journey efficiency for the short trip out to the pub from a cold start looks to have been about 397 Wh/mile. The initial cabin temperature, before pre-heating, was 2°C. The battery pack may have been a bit warmer, as the temperature here yesterday rose to around 8°C or 9°C I think

The trip back from the pub, with no pre-heating ( was only sat for 8 minutes) used 2.09 kWh, so about 443 Wh/mile. There's very little height difference between the two locations, the pub is about 69 feet lower than our house, and there's another valley on route, so I have to drive up from the bottom of our valley, down to the bottom of the next valley, up out of that again and down to the bottom of the valley where the pub is. The hills in between are about 200ft high.

 

[Adopado]

Not that much. The trip to the pub (which was the one from a very cold start was 4.71 miles and used 1.57 kWh, so about 333 Wh/mile. It's hard to be sure exactly how much battery power was used during the preheating period from the data display, but it looks as if it was probably about 0.3 kWh at the most, so the true journey efficiency for the short trip out to the pub from a cold start looks to have been about 397 Wh/mile. The initial cabin temperature, before pre-heating, was 2°C. The battery pack may have been a bit warmer, as the temperature here yesterday rose to around 8°C or 9°C I think

The trip back from the pub, with no pre-heating ( was only sat for 8 minutes) used 2.09 kWh, so about 443 Wh/mile. There's very little height difference between the two locations, the pub is about 69 feet lower than our house, and there's another valley on route, so I have to drive up from the bottom of our valley, down to the bottom of the next valley, up out of that again and down to the bottom of the valley where the pub is. The hills in between are about 200ft high.

This kind of detail is absolutely relevant when people refer to expecting the car to have a particular range! This is real life usage and can't possibly be accounted for by giving a simple range figure.

 

[Glan gluaisne]

This kind of detail is absolutely relevant when people refer to expecting the car to have a particular range! This is real life usage and can't possibly be accounted for by giving a simple range figure.

To put those short trip (albeit with mains powered pre-heat) numbers into perspective, the lifetime (over nearly 14 months) energy efficiency is running at 295 Wh/mile overall. The data suggest that the true mean efficiency (correcting for the car only having been owned for one summer and 1 and a bit winters) is about 245 Wh/mile.

Trying to better describe what the numbers mean, in terms of real range, assuming the battery has a usable capacity of 77 kWh (this is debatable, as Tesla have been a bit coy about the true figure), then we get the following range numbers:

Using the estimate of true mean efficiency of 245 Wh/mile gives a range of 314 miles

Using the actual lifetime efficiency to date of 295 Wh/mile gives a range of 261 miles

Using the pre-heated short trip efficiency from last night, of 333 Wh/mile gives a range of 231 miles

Using the non-preheated return short trip last night, of 443 Wh/mile gives a range of 174 miles

It's easy to see the short term variation in apparent range and just what a hit short trips in the cold seem to make to the apparent range. It's also pretty clear that it's unreasonable to take the data from a short trip, or series of short trips, and try and use that data to indicate real world range for a longer trip. Right now, in all probability the real world long trip range for my car is probably around 250 to 260 miles, roughly in line with the lifetime efficiency number, not the 174 miles range estimate from using the data from my trip back from the pub last night.

 

[Adopado]

It's easy to see the short term variation in apparent range and just what a hit short trips in the cold seem to make to the apparent range. It's also pretty clear that it's unreasonable to take the data from a short trip, or series of short trips, and try and use that data to indicate real world range for a longer trip.

I think this is the key. It is as unreasonable to quote a dismal range based on cold weather short trips as it is to have a range based on warm weather long distance flat land trips. I am torn between thinking there should be a spread of typical ranges advertised or trying to move away from the focus on range altogether. The advantage in advertising ICE vehicles is that the total tank range is never worthy of quoting .. we rarely think about it and it never affects a buying decision. IMHO Tesla range should be approaching that same possibility with just a modest increase in cold weather range.

 

[mrobins64495]

Interesting post.

I’d say I’d probably be fairly unhappy with 50 miles of range, it seems a little low to me.

My LR seems to be averaging 200 miles in winter from 90% range, this has more to do with my driving style atm. I think I could probably get 230/250. For every 70 miles I use approx 20% battery on the trip to London. Worst I’ve seen is 25%.

Summer driving best I got was 15% battery over 70 miles or around 198kwh for the trip. I’ve come to expect the drop in winter.

I too am on octopus go. I only ever charge at 5p or so per kWh to save cash. This works for my work pattern.

 

[Peteski]

The problem is that because range is quoted in the spec, noob EV drivers automatically expect to achieve that range regardless of conditions or driving style. So if range is quoted at 360 miles and they only get 300 miles, or whatever, then they feel cheated. Plus they are horrified when they try to extrapolate total range from a 2 mile commute in freezing weather!

As EVs become more mainstream, people will work it out for themselves as they have done with ICE cars. The difference is that range is usually more critical in an EV and draws your attention to how efficiency actually changes with weather, type of route, etc.