To AC or not to AC…

[PaulC82]

Just got a ZS EV and loving it. However, coming from a fossil car and my “only use AC when the outside temperature is above 24 degrees, to save fuel” mentality, does the same apply to EVs?

Is it more efficient, conversely, to just set the climate control to a temperature and leave it in auto?

Would be interested to read how other people handle their heating in these cars.

 

[JCFlippen]

Have you got the long range model? If so I would not worry about it.

 

[PaulC82]

Standard range

 

[DB Go Rex]

Just got a ZS EV and loving it. However, coming from a fossil car and my “only use AC when the outside temperature is above 24 degrees, to save fuel” mentality, does the same apply to EVs?

Is it more efficient, conversely, to just set the climate control to a temperature and leave it in auto?

Would be interested to read how other people handle their heating in these cars.

The most efficient option (if that's what your aim is) is to never run the HVAC at all. Both the resistive heater and the AC consume energy from the battery - which will be running for a lot of the year if you set the climate control to say 20C and forget it.

That's the same as with an ICE car - with the main difference being in winter you get the 'free' energy from the inefficiency of the engine lost as heat into the cabin - EVs don't have that level of heat loss inefficiency so have to run a heater.

The AC will reduce range in both ICE and EVs.

Eco mode is an option in the MG as that restricts the performance of the HVAC system, but comes with the negative of dull throttle response.

 

[Jomarkh]

You will use more battery travelling at 70 mph instead of 65mph than using acc.

 

[Gadget Geek]

AC efficiency varies at different speeds due to the drag coefficient. Below 50mph, open the windows and sky roof (if you have one). Above 50mph, the turbulant air flow caused by the open windows/roof increases the drag coefficient which is when AC is more efficient.

Mythbusters did an episode on it many years ago.

 

[drmcw]

It's a car why use it any different to a fossil one? Did you ever drive your old car and say to yourself I'll save some fuel and switch off as much stuff as I can? Oh looks like you did; it's your car do with it as you will! As Jomarkh said if you really want to save fuel then driving more efficiently is the best way to do it.
[Edit] As you're new to things then one thing that can make a difference, especially when cold, is pre-heating or pre-cooling. You can use the app to switch the climate control on so have a frost free and warm car or a cool one if it's hot. If the car is plugged in then it'll be less of a hit on the battery before you set off.

 

[PaulC82]

It's a car why use it any different to a fossil one? Did you ever drive your old car and say to yourself I'll save some fuel and switch off as much stuff as I can? Oh looks like you did; it's your car do with it as you will! As Jomarkh said if you really want to save fuel then driving more efficiently is the best way to do it.

Yeah you make a good point. Only at the peak diesel prices recently did I really start to think about efficiency in terms of fuel cost. But yeah, I’d leave the engine running to defrost it in the winter, ac on max in the summer.

I don’t know if it’s because of the high purchase cost of EVs, but I do rather think about efficiency more. I do find myself naturally driving slower now though, because it’s such a chilled experience driving an EV.

 

[Lovemyev]

A brilliant feature of the car over its ICE counter parts, is having the facility to pre heat / cool the car ( if the App is working that is ).
Say goodbye to scrapping the glass in the winter and entering a boiling hot car in the summer !.

 

[Lovemyev]

I do find myself naturally driving slower now though, because it’s such a chilled experience driving an EV.

This appears to be a common practice to be honest !.
Not really to conserve the range ( but it helps ) but it’s a more sedate / chilled out driving experience.
But when you want to drive with a a little more pace, it car show a clean pair of heals to a lot of ICE cars alright !?.

 

[drmcw]

Yeah you make a good point. Only at the peak diesel prices recently did I really start to think about efficiency in terms of fuel cost. But yeah, I’d leave the engine running to defrost it in the winter, ac on max in the summer.

I don’t know if it’s because of the high purchase cost of EVs, but I do rather think about efficiency more. I do find myself naturally driving slower now though, because it’s such a chilled experience driving an EV.

Well it makes me think about energy costs but then that's probably the same for pretty much everyone at the moment whether they have an EV or not! I suppose efficiency is more to the fore in an EV because their ranges are much less than equivalent ICE vehicles and its far easier and more immediate to see how efficient or inefficient you are being on a journey. It tends to become something of a game to see how high you can get the miles per kWh figure!

 

[PaulC82]

Well it makes me think about energy costs but then that's probably the same for pretty much everyone at the moment whether they have an EV or not! I suppose efficiency is more to the fore in an EV because their ranges are much less than equivalent ICE vehicles and its far easier and more immediate to see how efficient or inefficient you are being on a journey. It tends to become something of a game to see how high you can get the miles per kWh figure!

What’s achievable on these cars? I’ve had mine up to 4.2m/kWh for a shortish trip recently.

 

[Ruislip Resident]

The most efficient option (if that's what your aim is) is to never run the HVAC at all. Both the resistive heater and the AC consume energy from the battery - which will be running for a lot of the year if you set the climate control to say 20C and forget it.

That's the same as with an ICE car - with the main difference being in winter you get the 'free' energy from the inefficiency of the engine lost as heat into the cabin - EVs don't have that level of heat loss inefficiency so have to run a heater.

The AC will reduce range in both ICE and EVs.

Eco mode is an option in the MG as that restricts the performance of the HVAC system, but comes with the negative of dull throttle response.

The dull throttle is relative to the other settings of normal and sport. Compared to the ICE vehicles I had before Eco is vastly more responsive and faster. I only use the AC when necessary. Once its cooled enough I just have the fans on without the AC. Like wise in the winter. Heat till its warm enough then turn off, giving short tops up when required. What you wear can make a big difference in winter. If you have the sun shade (the fabric bit), open in winter to let radiant heat in on any 'sunny' days but shut to keep heat out on hot days Keep the doors closed as much as possible when getting in and out to maintain the desired temperature as much as possible. I was getting high 3's efficiency most of the winter bar the sub 0 degrees days when it was mid 2s to low 3s. At the moment I nearly always get above 4 once I have driven a couple of miles or so. Quite often I will get to 5. Driving from Ruilsip (West London) to Hayling Island (nr Portsmouth) for the early May bank Holiday for an 85 mile journey on motorways and fast A roads I got 4.1 miles per kwh. That was driving in perfecly acceptable temp comfort on eco setting using ACC (the MG pilot setting as the lane assist is less intrusive when on that). If I neded a blast of cold air I'd switch to normal mode and put the AC on for a couple of minutes. If I came to a big downhill section I'd gently touch the breaks. This would switch ACC off so I could get the regen. Once on the flat again I would simply reset the ACC (MG Pilot position) but pressing the activate / turn on button on the end of the stalk.

 

[drmcw]

What’s achievable on these cars? I’ve had mine up to 4.2m/kWh for a shortish trip recently.

Well at the moment if I get under 4 then I've been in a hurry but averaging about 4.2. Have seen over 5. I'd be happy with 3+ in the winter and 3.3+ on the motorway. Not had this car that long myself so still learning; my leaf used to be about around 4 in winter and 5 in summer; if not tanking it!

 

[Lovemyev]

What’s achievable on these cars? I’ve had mine up to 4.2m/kWh for a shortish trip recently.

Well …….. That’s a topic that could go on all day TBH ?.
No two people will ever produce the same results in any situation really.
Winter consumption will be low and summer figures will see a massive improvement.
Yesterday we had a steady drive with a mix of dual carriageway and some “B” roads and town work.
Covered about 130 miles and the efficiency touched 5.0 M/kwh overhaul.
In really good weather conditions and with no use of the HVAC system, the car only sip’s at the range from the battery.
I find that the GOM does a pretty decent job of estimating the range.
We are on our second ZS EV now and after a while, you will find you get more confident about the range and stop looking at the GOM every couple of minutes ?.
Our second ZS EV is the LR model and I don’t even look at the remaining range until I see the range indicator turn from green to amber.
Then a very quick glance and carry on driving.
In very cold winter conditions you will see an instant drop of about 10+ miles of predicted range, when you have the HVAC running on a high setting.
I can except that drop in exchange for getting into a fully defrosted toasty cabin !.
The car sits on the drive all year round and is exposed to everything the weather can throw at it.
Of course, I only go to the petrol station now for fuel for my lawnmower !.
Popped there last week with my 5 litre can and almost passed out when I seen the cost.
I could have charged the car twice ( at home ) and covered hundreds and hundreds of miles for the same cost outlay of that fuel ️.
It is normal for owners to cover more miles when they purchase an EV over their previous fossil cars they once owned.
This because they enjoy driving them and they can afford to use them more often.
My wife has a so called economic to run, Fiat 500.
We hardly use it because the EV is much cheaper to run.
Normally we would cover about 7 - 8,000 miles in our previous ICE cars.
We covered almost 20,000 in two years in our Gen1 ZS EV and now our 14 month old Gen2 ZS EV LR has covered 11,000 miles already.
“Do the math, like our American friends say.
Get out and enjoy your EV as much as possible.
We all except I think that EV’s are way too expensive, just to have them sitting on the drive devaluing.
All cars lose their value over time, but if you can “off set” the lose against the use, then that’s perfectly fine with me.
Loosing thousands of £’s on a car that is only a couple of years old and over covered a few miles, is an expensive luxury in my mind.

 

[pollenface]

Using the AC for me reduces range by about 10kms.

On a 35C day, I want AC.

 

[Lovemyev]

I find cooling consumes a little less energy than heating in the U.K. !.
No surprise there then ?.

 

[Matt M]

I assume the mk2 is the same as the mk1. Here’s what I do. I only use the fans a/c if stationary in traffic. Once I’m moving I ensure the vents are set to face level, switch off and ensure the recirculate is off. You still get fresh air coming through the vents. Unless its really warm then I say bugger it and just charge it more ? might help you

 

[Lovemyev]

I assume the mk2 is the same as the mk1.

Just for ref : - The Gen 1 has a more simple basic manual HVAC system, where as the Gen2 has slightly more advanced climate control system.
Had both models, both worked just fine for me TBH.
Just a bit more intervention needed from time to time, with regards to the manual system, but no big deal .