PHEV Cabin Heater

[Director76]

Originally Posted by Philip Fisher

I am pretty sure - although not 100% - that if you have a petrol powered pre-heater then you do not have an electric one as well. ie it is one or the other, not dual fuel.

Yep, agree - this

Ps Petrol aux heater works plugged in or not. As for the electric preheat on MY22 on, anyone know?

[Lozzingers]

Originally Posted by Director76

Yep, agree - this

Ps Petrol aux heater works plugged in or not. As for the electric preheat on MY22 on, anyone know?

I've got a MY22 T8 with just the standard electric heater. I've used the pre heat function this week a few times when car is plugged in overnight. I was assuming/hoping it would use the plug electricity to heat up the car etc, but I don't believe it does. The range is reduced by about 3-5 Miles (and %battery down about 15%) when we start the car.
I also tried getting in the car when still plugged in and heat the cabin, but it doesn't let you start the car with the cable plugged in!
We are just using a 3pin plug at present in case that makes a difference, but I was really looking forward to the pre heat in winter, but can't do it if it kills the range so much!

[Director76]

Originally Posted by Lozzingers

I've got a MY22 T8 with just the standard electric heater. I've used the pre heat function this week a few times when car is plugged in overnight. I was assuming/hoping it would use the plug electricity to heat up the car etc, but I don't believe it does. The range is reduced by about 3-5 Miles (and %battery down about 15%) when we start the car.
I also tried getting in the car when still plugged in and heat the cabin, but it doesn't let you start the car with the cable plugged in!
We are just using a 3pin plug at present in case that makes a difference, but I was really looking forward to the pre heat in winter, but can't do it if it kills the range so much!

Thanks, this is really interesting, and what I expected in terms of range impact. I think I got the last model year with the petrol heater (MY21.5) and the preheat capability (without any significant battery impact) is one of the best features of the T8 (I’d certainly have missed it having got very accustomed to using it on our previous MY18.5).

Petrol heating is not the environmentally preferable option perhaps, but a PHEV is a compromise anyway.

I assume you also rely on battery to heat the car whilst driving in pure too?

Re use of mains power when plugged in, you get a similar effect if you run the preconditioning in the summer plugged in, battery not mains is used to drive the A/C. In summer, unplugged, there is no AC at all on air recirc.

If they’d deleted the petrol heater in parallel with the new 18kW it would have made sense (losing 5 miles is much less significant on a bigger range), but I sense the PHEV power train upgrade was delayed (hence why it came out a few months later than than the Xc60 facelift), by which time they were on with increased supply of electric cabin heaters, and cancellation of order of petrol heaters from Webasto!!

[griffin447]

Originally Posted by Lozzingers

I've got a MY22 T8 with just the standard electric heater. I've used the pre heat function this week a few times when car is plugged in overnight. I was assuming/hoping it would use the plug electricity to heat up the car etc, but I don't believe it does. The range is reduced by about 3-5 Miles (and %battery down about 15%) when we start the car.
I also tried getting in the car when still plugged in and heat the cabin, but it doesn't let you start the car with the cable plugged in!
We are just using a 3pin plug at present in case that makes a difference, but I was really looking forward to the pre heat in winter, but can't do it if it kills the range so much!

The preheat function uses the plugged in electricity over the battery. If you are just using the 3 pin plug I don't think it works with this as it's too great a power draw. I've got a type 2 charger on my drive and it works off that when I'm on pre heat. Absolutely no reduction in battery and means I get an extra 3/4 miles of range when driving in pure and about 2 miles when driving in hybrid.

[Stoods]

Originally Posted by Lozzingers

I've got a MY22 T8 with just the standard electric heater. I've used the pre heat function this week a few times when car is plugged in overnight. I was assuming/hoping it would use the plug electricity to heat up the car etc, but I don't believe it does. The range is reduced by about 3-5 Miles (and %battery down about 15%) when we start the car.
I also tried getting in the car when still plugged in and heat the cabin, but it doesn't let you start the car with the cable plugged in!
We are just using a 3pin plug at present in case that makes a difference, but I was really looking forward to the pre heat in winter, but can't do it if it kills the range so much!

Hi this doesn’t seem right? I have a MY21 T8 S90 charging on a 3pin plug as you do but I don’t see any decrease in range or battery percentage when using the Pre-climate function.

I usually manually switch mine on while getting ready in the morning and it takes 30mins to get the cabin to temperature.

From what I can see on my domestic power meter, when it clicks on in the morning it’s drawing around 1 -1.5kW maximum.

I am not 100% sure what mechanism it uses to heat but I can certainly “smell” a faint burn when entering car (fuel heater) plus of course the heated seats, screen will be drawing some current.

You can do this when not “plugged in” also of course and in this case I assume it is taking energy from the batteries, but when plugged in, I can confirm I start the journey with 100% charge (24-25 miles range).

Hope this help.

[Director76]

Originally Posted by Stoods

Hi this doesn’t seem right? I have a MY21 T8 S90 charging on a 3pin plug as you do but I don’t see any decrease in range or battery percentage when using the Pre-climate function.

I usually manually switch mine on while getting ready in the morning and it takes 30mins to get the cabin to temperature.

From what I can see on my domestic power meter, when it clicks on in the morning it’s drawing around 1 -1.5kW maximum.

I am not 100% sure what mechanism it uses to heat but I can certainly “smell” a faint burn when entering car (fuel heater) plus of course the heated seats, screen will be drawing some current.

You can do this when not “plugged in” also of course and in this case I assume it is taking energy from the batteries, but when plugged in, I can confirm I start the journey with 100% charge (24-25 miles range).

Hope this help.

MY21.5 and before - petrol auxiliary heater (very low battery draw plugged or unplugged), MY22 on, uses main PHEV battery to run electric auxiliary heater for preheat

[rhd443]

Originally Posted by Philip Fisher

I am pretty sure - although not 100% - that if you have a petrol powered pre-heater then you do not have an electric one as well. ie it is one or the other, not dual fuel.

This is correct, you will smell the fumes from the aux heater whether its plugged in or not, the way to test is let your fuel light come on, if you cant do preconditioning with low fuel then its not electric capable.

[wrxseeker]

Originally Posted by rhd443

This is correct, you will smell the fumes from the aux heater whether its plugged in or not, the way to test is let your fuel light come on, if you cant do preconditioning with low fuel then its not electric capable.

Pretty sure my low fuel light was on and the car isn’t plugged in but it allowed me to start precondition via the app and it sounded like it started the aux petrol heater.

Of course the fuel light may have been borderline on/off when I parked it.

[Automatic Only]

Originally Posted by wrxseeker

Pretty sure my low fuel light was on and the car isn’t plugged in but it allowed me to start precondition via the app and it sounded like it started the aux petrol heater.

Of course the fuel light may have been borderline on/off when I parked it.

The petrol heater will still work with the fuel light on so long as the fuel level isn't really low. Once it drops to around 20 miles range the petrol heater won't start.

[Director76]

Originally Posted by Automatic Only

The petrol heater will still work with the fuel light on so long as the fuel level isn't really low. Once it drops to around 20 miles range the petrol heater won't start.

I think the logic controls here have changed.

On our MY18.5 as soon as the fuel light came on the aux cabin heater was isolated, paradoxically this then would trigger the ICE to start up more to provide cabin heat, which must have used more fuel than the aux heater….

As noted by Auto Only…I think this behaviour has changed on more recent versions, can’t say I’ve noted it on our MY21.5.

I always wondered whether it was because aux heater fuel use was perhaps not ‘metered’ in the same way and allowing it to continue functioning may have inadvertently resulted in more fuel run outs if it wasn’t being factored into the range. Maybe this has now changed, or maybe it was just an unintended control logic that had been written out now