Model 3 Efficiency

[FEERSUMENDJIN]

I asked this in another part of the forums but I was advised to ask here for more specific answers.

Hi, I'm planning on buying a model 3 LR in the next 2-3 years, my question to you is that I stay in Scotland and I want to know what kind of range/efficiency I'll be getting. On average we get temperatures of around 11°c annually, winter it is on average of 0°c and summer is around 16°c.
Any help would be greatly appreciated and to keep it simple I am talking about the current ranges on the model 3 LR (360 miles)

I would prioritise getting a home charger. Just makes everything good. Especially winter commute when you set the car to be ready to go by the right time. This means the car is at a good temperature for you and the battery. We get over 90% of the rated range on A road commutes in Fife in typical Scottish single digit temperatures. Autopilot helps you keep your lead foot in check !

 

[Alan J]

If you do get an email back if you could let me know either here or via pm that would be much appreciated. If it turns out my council is beginning to charge then I may try and get a home charger installed quicker than I was planning.

I've had my SR+ for 15 months and have relied on the Charge Place Scotland Network which has been occasionally flaky but mostly OK but with the numbers of EVs and especially Teslas on the roads and the Council's starting to charge I am progressing a Home Charger. Using Octopus Agile or Go while not free is a lot cheaper and more convenient than the other options.

 

[Beery]

I would prioritise getting a home charger. Just makes everything good. Especially winter commute when you set the car to be ready to go by the right time. This means the car is at a good temperature for you and the battery. We get over 90% of the rated range on A road commutes in Fife in typical Scottish single digit temperatures. Autopilot helps you keep your lead foot in check !

I've had my SR+ for 15 months and have relied on the Charge Place Scotland Network which has been occasionally flaky but mostly OK but with the numbers of EVs and especially Teslas on the roads and the Council's starting to charge I am progressing a Home Charger. Using Octopus Agile or Go while not free is a lot cheaper and more convenient than the other options.

In my current situation a home charger isn't very viable, I hope by the time I'm ready to buy my tesla that will change but if it doesn't then the chargeplace network seems like my best bet until I am able to get a home charger installed.
I have saw the octopus energy is what a lot of ev owners use and I will definitely be giving that thought closer to the time.

 

[Nick77]

Just wanted to talk about drive efficiency from the last two days.

I've noticed that having the AC off has made a big impact. The hot weather meant its been running constantly, but then yesterday I tried turning it off and just having the front windows down.

I've gone from 70-80% on drives to 95-100%+

For instance I drove to the Leicester Supercharger yesterday. On the way there it was carriageway + motorway with AC on all the way and that gave me 80%. On the way back I went via A-roads after a short motorway blast, but kept the AC off with the windows down. Efficiency jumped to 106%!! Even though it was 10 miles shorter. Obviously slower average speeds mean better efficiency in general but that's a massive jump.

A short trip today to the driving range and back have both given 121%!! and 95%.

I'm quite stunned just how much the AC affects efficiency, particularly given that I'd read previously that AC didn't make a massive difference, and shorter journeys were supposedly less efficient.

Edit - Is efficiency better with a fuller battery? I arrived at the Supercharger with 5% left, but drove back from 90%.

 

[exlatccatsa]

Interesting! I'd always read that a car was more efficient with windows closed and AC on. I'll have to do some experimenting.
My other half is of an age where she needs instant cooling ( I went through that years ago) consequently if the car is sitting at 15c on AC she will still.open the window to "get cool" when it's 26c outside. Perhaps I should be encouraging her to open the window more often?

 

[Nick77]

Interesting! I'd always read that a car was more efficient with windows closed and AC on. I'll have to do some experimenting.
My other half is of an age where she needs instant cooling ( I went through that years ago) consequently if the car is sitting at 15c on AC she will still.open the window to "get cool" when it's 26c outside. Perhaps I should be encouraging her to open the window more often?

Blimey 15c is pretty cold on AC.

Tell them to stick their head out the window with their tongue hanging out, like Dougal in Father Ted!

 

[MrBadger]

For instance I drove to the Leicester Supercharger yesterday. On the way there it was carriageway + motorway with AC on all the way and that gave me 80%. On the way back I went via A-roads after a short motorway blast, but kept the AC off with the windows down. Efficiency jumped to 106%!! Even though it was 10 miles shorter. Obviously slower average speeds mean better efficiency in general but that's a massive jump.

Battery pre conditioning has a big impact on efficiency, at least it does on our non heat pump car. So your trip to supercharger is likely to have had a significant impact on efficiency.

I found that A/C has negligible difference on efficiency (at least within the normal variance of a regular journey), but fan speed does. As a result, we just stick to manual control unless the cabin needs significant cooling in which case we leave it on auto. In winter we run A/C and low fan (1-2) pretty much all the time.

 

[Nick77]

Battery pre conditioning has a big impact on efficiency, at least it does on our non heat pump car. So your trip to supercharger is likely to have had a significant impact on efficiency.

I found that A/C has negligible difference on efficiency (at least within the normal variance of a regular journey), but fan speed does. As a result, we just stick to manual control unless the cabin needs significant cooling in which case we leave it on auto. In winter we run A/C and low fan (1-2) pretty much all the time.

Cheers. Fan speed was about 4-5 I think so that could account for it. I'll try at lower settings.

 

[Jason71]

Battery pre conditioning has a big impact on efficiency, at least it does on our non heat pump car. So your trip to supercharger is likely to have had a significant impact on efficiency.

I found that A/C has negligible difference on efficiency (at least within the normal variance of a regular journey), but fan speed does. As a result, we just stick to manual control unless the cabin needs significant cooling in which case we leave it on auto. In winter we run A/C and low fan (1-2) pretty much all the time.

have you really found fan speed has much of an effect when cooling?
When heating with a non heatpump car . I have always assumed that the input to the heater would be reduced if the fan was set to low otherwise the air would get too hot. So while I agree that having the fan lower while heating has a big impact I have always assumed it was due to the lower heater output input rather than the fan itself. fans do not use much power.
Conversely car AC is rarely powerful for the air stream to be too cold so with the fan on low the air stream is often just a bit cooler so the only saving is the lower fan energy which I thought would be minimal. There might be some reduction in power to the cooler but not that much.
I don't like to be hot so I will not be changing my cooling behaviour either way but just interested. Not what I expected.
The car overall is sooo much more efficient in hot weather anyway its hard to notice the impact of the AC unless specifically looking for it

 

[MrBadger]

I found the difference that fan speed makes to energy use by observation. I was curious and found an article that backed this up. I just tried to find that article but couldn't (the one that I was looking for iirc specifically mentioned fan consumed power), but found this one instead Tesla Model 3 Efficiency & Vampire Loss — How To Save Energy which on a quick glance seems to be saying the same. About half way through the article is this graph. Of course, this one is combined fan and A/C usage rather than just fan. When I looked into the fan speed I never differentiated between fan power and heater/AC power.

I do know from home energy monitoring that a fan can draw a surprising amount of power, although not in the same league as a heating element. I think my turbo trainer fan draws north of 100W at higher speeds. Our home HVAC draws 28W continuously on normal setting - and thats a high efficiency fan running at 20% speed. At 100% purge mode, its around 170W. But thats still cheaper than leaving the windows open in winter. Not huge in the Wh/mile scheme of thing though but noticeable. The figures on the graph below would have a much bigger impact.

 

[Blokie]

I found the difference that fan speed makes to energy use by observation. I was curious and found an article that backed this up. I just tried to find that article but couldn't (the one that I was looking for iirc specifically mentioned fan consumed power), but found this one instead Tesla Model 3 Efficiency & Vampire Loss — How To Save Energy which on a quick glance seems to be saying the same. About half way through the article is this graph. Of course, this one is combined fan and A/C usage rather than just fan. When I looked into the fan speed I never differentiated between fan power and heater/AC power.

I do know from home energy monitoring that a fan can draw a surprising amount of power, although not in the same league as a heating element. I think my turbo trainer fan draws north of 100W at higher speeds. Our home HVAC draws 28W continuously on normal setting - and thats a high efficiency fan running at 20% speed. At 100% purge mode, its around 170W. But thats still cheaper than leaving the windows open in winter. Not huge in the Wh/mile scheme of thing though but noticeable. The figures on the graph below would have a much bigger impact.

If that's from August 2020, that will be pre-heatpump, so would be interesting to see how the new models perform.

 

[Peter 224]

I have a May 2021 LR, since collection it has averaged 260wh/mile.but power consumption is very variable. Our daily drive to the stables, 1.4miles, will used 450wh/mile, on the other hand a recent 144 mile trip averaged 255, but much of that was at 50mph on the M25 roadworks. As of 11 am on 11 July the car has 82% charge and it thinks that will give me 213 miles, which is nonsense.

The real question is "what is the real world capacity of the battery?" I believe that the LR has a usable capacity of 77.5kw, but some reports say it is 82kwh: but I stand to be corrected.
Eliminating the top and bottom 15% that gives 54.25 kw/h or 58.1kwh of usable power, at 0.26kw/mile that is a range of 208 or 233 miles and a maximum range, charging to 100% and going down to 5% of 283 to 300 miles.

Without the Supercharger network I would struggle to do some longer trips, with it the Tesla is perfectly viable.

The car has a heat exchanger, so it will be interesting to see what happens in the winter, but down here in the south west of Wiltshire winters tend to be a bit of a non event.

I charge mostly at home, where I pay about 13.83p/kwh (including the daily standing charge), thanks to a tariff with Scottish Power I locked into in 2019, it expires in May 2022 when I fear I will have a nasty surprise.

I do as all suggest, charge based on expected use, but not more than 85% unless I'm going off on a 100 mile plus trip. I tend to charge when it falls to 20%, or thereabouts. I've used a supercharger once, mainly because I want to use some of the "free 1000 miles"!

 

[Keithgrif]

My daily commute is 18 miles each way, 15 of which is on dual carriageway @65 (cruise control on), the rest on country roads. This time of year that gives me 250-270W/mile. In the winter when I first got it the efficiency was closer to 280-300W/mile.

I've only done 2 long journeys thanks to COVID but managed a range of only 200 miles on both ( motorway @65-70mph). Long way from the advertised range, shows how important speed can be for efficiency.

 

[ACarneiro]

Yeah I’m hoping by then there will be a reduction in cost of the car aswell as improved efficiency in the cold as giga Berlin will be up and running by then.

I hate to disappoint, but efficiency savings are u likely to be translated into price reductions unless there is market pressure.
At the moment Tesla are selling everything they make and car prices have actually been going up, not down. They are more likely to pocket the improved margin as long as they keenselling everything they make.
Hopefully that won’t be forever, as other manufacturers start getting more established and better alternatives come to market.