T8 mpg

[AB-UK]

Originally Posted by yeoman

The figures reported by real owners of a T8 on this and other forums ,suggest car and driver are very wrong.

This is exactly what I want to know and why I started this thread.
Continued updates and confirmation of actual mpg achieved by "real" owners and drivers will doubtless be useful for existing and prospective buyers of the T8.

[pagan8c]

I think if I could afford a T8 that MPG would not be 1 of my main considerations. I suspect I would prefer the D5 version because I am not sure about the electric part being of much use . I was told when I got the XC70 after the V70 it would be a lot worse on fuel but in actual fact it is not really much worse and I for 1 would not change back to a V70 just because it was slightly better on fuel. I don't do big mileages so for me it doesn't matter too much but by the same token I am on a pension so can't replace money spent easily. My first reason to have a car is I like being in it and it does the job I want it too. If it is reasonable on fuel then it is a bonus.

[Lexman8]

Originally Posted by Deman77

I get 27.5 combined on D5 now fuel heater is on all the time - was 29 before winter.

I'm thinking of specifying the fuel heater. How effective is it? Do you find it makes a difference?

[Clan]

Originally Posted by yeoman

The comment from car and driver strikes me as slightly disingenuous.
There are just too many variables in any hybrid car and how it is used and driven, to state what you get as an average mpg without qualifying how the car was driven.
We have no idea whether the driver was accelerating like he stole the car,had the AC on full blast,is slightly hard of hearing and needed the audio at full blast etc.

The figures reported by real owners of a T8 on this and other forums ,suggest car and driver are very wrong.

I know of 2 V60 hybrids which are doing well over 100 mpg , in the 130 - 140 range , they must be being driven on the kind of routes they were designed for and running on battery for the last 30 miles of the journey and being recharged overnight ..

[Rojah]

Originally Posted by Lexman8

I'm thinking of specifying the fuel heater. How effective is it? Do you find it makes a difference?

I think that there's a really interesting point here, and one I hadn't paid any attention to until now.

The fuel heater on the T8 has two separate and independent functions, namely working as a parking heater or as an additional heat source when the car is running ( especially in hybrid or pure mode, as the petrol engine won't be working for much of the time).

I haven't thought about how much fuel it uses, but now will carry out some tests, like filling the petrol tank up to the brim, running the heater for 40 mins (max permitted time), then seeing how much it has guzzled. For the additional heater, I am not sure if the fuel used is signalled to the trip computer (maybe someone at Volvo knows?), but I could again do a tank fill, and compared fuel used versus computer mpg/fuel used.

Or alternatively, I could get a life and do nothing....

What I do now on really cold mornings is to set the Parking Heater on for about 5 mins before I get in the car, start the car in hybrid mode and dab the accelerator just enough to get the ICE started, which will run for a couple of minutes. The car will be warm enough for the next 20 mins or so to run in pure or hybrid mode, until I get onto the motorway.

Why do I start the ICE for a short time? Well should a full burst of acceleration be required on a really cold engine/gearbox, better that it has warmed through a bit rather than 400+ bhp being generated by a stone cold engine!

That's all for now

Rojah

[Lexman8]

Originally Posted by Rojah

What I do now on really cold mornings is to set the Parking Heater on for about 5 mins before I get in the car, start the car in hybrid mode and dab the accelerator just enough to get the ICE started, which will run for a couple of minutes. The car will be warm enough for the next 20 mins or so to run in pure or hybrid mode, until I get onto the motorway.

So is 5 minutes of the fuel heater plus 2 mins of the engine enough to begin to warm the car and to what extent? Would be interesting to know what effect running the fuel heater on its own for say 10 or 15 mins would have.

[Deman77]

Originally Posted by Lexman8

So is 5 minutes of the fuel heater plus 2 mins of the engine enough to begin to warm the car and to what extent? Would be interesting to know what effect running the fuel heater on its own for say 10 or 15 mins would have.

It gets very very comfortable in the car very quickly. It also reduces engine wear - you can feel the diesel work smoother on cold days and the gearbox doesn't hold the gears as long when accelerating. I don't think 5min would make a difference for the engine though. If you set it to pre-heat for certain times (it asks you when you want the car ready) it starts it 30min before the car should be ready. The manual doesn't recommend you run it any longer than the trip you will have as it does use up battery charge and you want it to recover during the trip. It may refuse to start preconditioning if the battery charge is low. It's a great option. In T8 it's standard as they want you to warm up the battery for optimal performance

[Lexman8]

Thanks for that. One of the issues I have with a diesel is how long it takes to warm up. Sounds like a no-brainer option then.
_

[Rojah]

Originally Posted by Deman77

It gets very very comfortable in the car very quickly. It also reduces engine wear - you can feel the diesel work smoother on cold days and the gearbox doesn't hold the gears as long when accelerating. I don't think 5min would make a difference for the engine though. If you set it to pre-heat for certain times (it asks you when you want the car ready) it starts it 30min before the car should be ready. The manual doesn't recommend you run it any longer than the trip you will have as it does use up battery charge and you want it to recover during the trip. It may refuse to start preconditioning if the battery charge is low. It's a great option. In T8 it's standard as they want you to warm up the battery for optimal performance

Thanks for that, I must study the owners manual more, and I am keen to understand how the heater actually works in order to heat the engine block and battery. I do think that I am probably not letting it preheat the car for long enough on frosty mornings, though I think that 30 mins might be a bit extravagant on fuel.

On my previous hybrids (Lexus RX's and Plug in Prius), when it was cold the engine would start until it had reached operating temperature, whether stationary or not - this would have a marked effect on petrol consumption. The Volvo doesn't seem to work like this, as in hybrid or pure mode the ICE stays off or shutdown, unless provoked by a heavy foot, and then it will stay running for a couple of minutes only

[Lexman8]

Originally Posted by Rojah

The Volvo doesn't seem to work like this, as in hybrid or pure mode the ICE stays off or shutdown, unless provoked by a heavy foot, and then it will stay running for a couple of minutes only

From what I've gathered, the fuel heater comes on with the ignition to provide heat when the engine/cabin is cold. As such, the engine isn't required and therefore forcing it on for a couple of minutes probably isn't as beneficial/effective as pre-heating the car for longer.