What should I do on a motorway for max MPG

[BigKeith1962]

Good Morning Everyone,

I spend a lot of time on the motorways and I have been trying to improve my MPG but due to mileage I cover my battery is often quite low and I don't want to stop at services to charge it.
Regardless of the SOC, what would you use/recommend for best mpg, ICC or using B0/B1 manually driving? Or anything else?

Thanks
Big K

 

[elm70]

There is no real magic

The rule is as slower as you drive, and as higher is the MPG

If you use CC you can't use B0 .. but CC is so convenient to use that make no sense to check if B2 is better then B0 .. (which is not at constant speed ... B setting is irrelevant while driving at constant speed)

I think to keep the car in automatic mode (no save, no charge) is in general a good option

My suggest is to consume the battery at the beginning of the trip (assuming the car was charged) .. that means using the car in normal/automatic mode

If the last X km/miles after the motorway are on normal / slow streets ... then you can plan to press charge ahead for have the final part of the trip in EV mode ... be careful on not overcharge the car, since every EV range left at destination is a waste of fuel , since is more convenient to charge the battery from the electric network then not while driving in parallel mode (charge in series mode, is something that should be avoided)

 

[jaapv]

I prefer to run the car in "charge" on fast motorway runs. As one never drives at a constant speed, I find it will keep the battery level approx halfway, which keeps a reserve for long inclines,accelerating, leaves some overhead for the bit when you get off the motorway, and is basically the most efficient state of the car. In the long run, I cannot see much mpg difference between charge, save or nothing. Nor by the B settings. I don't use those much anyway, as I use ACC a lot.

 

[twosout]

I’d suggest putting it into “Save” but, if the remaining ‘E’miles is less than the distance planned to be completed after leaving the motorway, “Charge”.
I’d also use ECO and regenerative braking.
Do you have any idea of your ‘raw’ mpg? I reckon mine is around 30mpg.

 

[BCbackroader]

My weekday routine is about 150km, 40 in towns, and 110 on the freeway, usually cruising at 125 kmh. In the year I've had the PHEV, I found that ECO + Charge on the freeway charges the vehicle enough to do the 40km town portions on EV only. I don't have the option to charge the car at home, strata rules don't allow it from common property outlets.


This gets me about 30mpg in cold weather (anything below 4C), and in the high 30s to low 40s in warmer times. Wit the ability to start with a full charge each day, I would expect a 15 - 20% increase in those numbers.

 

[twosout]

That’s much what I’d expect.
Never using the plug-in turns your vehicle into a pure hybrid and would provide a true measure of how the ICE element performs. Once you supplement fuel by adding electricity there has to be an assumption regarding the contributions made by that and the petrol.

I trust the advised EV ranges at the start and end of each journey and calculate the petrol consumption from the remaining distance on a spreadsheet.

Monitoring your consumption certainly reveals how much things like aircon and heating ‘cost’ you in terms of fuel, although I think that any heat recovered from the ICE could be considered as ‘free’ (no additional cost).

 

[cornclose]

although I think that any heat recovered from the ICE could be considered as ‘free’ (no additional cost).

In the Outlander with the electric heater (e.g. my 2019 4HS) is the heat *always* generated by the electric heater or does it come from the coolant when (and only when) the ICE is running ? i.e. are there two heaters ? One electric and one as per a conventional car with a coolant heater matrix ?

 

[elm70]

although I think that any heat recovered from the ICE could be considered as ‘free’ (no additional cost).

In the Outlander with the electric heater (e.g. my 2019 4HS) is the heat *always* generated by the electric heater or does it come from the coolant when (and only when) the ICE is running ? i.e. are there two heaters ? One electric and one as per a conventional car with a coolant heater matrix ?

If the ICE is running, the cabin heat come from the petrol engine.

There electric heater does heat a fluid which could be shared by the cooling liquid on the ICE ... so when ICE is running, I expect that the electric heater is not used .. but I did never really check .. still I'm quite sure the PHEV does not use electric heater, maybe only exception is at a start of a trip while the engine is still cold

 

[Trex]

although I think that any heat recovered from the ICE could be considered as ‘free’ (no additional cost).

In the Outlander with the electric heater (e.g. my 2019 4HS) is the heat *always* generated by the electric heater or does it come from the coolant when (and only when) the ICE is running ? i.e. are there two heaters ? One electric and one as per a conventional car with a coolant heater matrix ?

How it works is shown here:

This one is the Phev models with electric heater.



Image from MMC.

Now from the old image that was here I wrote,

For people in cold climates it says underneath this image that about 10 C or more difference between the setting of the climate control and temp of the interior starts the petrol motor. It also says max output of electric heater is 4.25kw.

Regards Trex.

Note the 4 way valve that can open to circulate engine coolant through the heater side circuit.

Also note the part I wrote underneath about the 10 C or more difference was before the PHEV had the EV priority button.

 

[ThudnBlundr]

You don't say what model you have, but my 4hs comes with adaptive cruise control which seems to use regen to slow down as much as possible. Looking at the power meter, it generates far higher regen than is available in 'D', though it still reverts to 'D' when disengaged.

Using EV on a fast road will tend to draw high power from the battery, which is generally seen as bad for degradation. So I put mine into Save whenever I'm travelling at speed, and use EV when travelling more slowly. To get the best MPG, you should always arrive at the next charge with an empty battery. I have used EH chargers at MSAs when on a long journey, but only when I was stopping for a break anyway. The 20-25 minute charge gives me enough time for a pee and a coffee.

I'm not sure that using Charge and running the engine all the time is the best way to achieve maximum fuel economy. Using Charge is not bad per se, as the car does that roughly 50% of the time when in Save or when the battery is showing empty. I have used it on long runs down to London, when I know that I will need as much EV as I can. It is almost certainly better to charge more efficiently in Parallel mode on the motorway and then use the battery when you would be charging less efficiently in Series mode.

Recently I have started flipping from Save to Charge on downhill sections on motorways, as the ICE will run at 75% throttle producing loads of power for the battery while consuming little power to move. I switch it back once the road levels out. This seems to produce extra range much more quickly than simply leaving it in Charge, and would appear to be more fuel efficient. But it's also getting a bit nerdy about it... :roll: :lol:

 

[maby]

The 50-odd thousand miles on our PHEV has been almost entirely motorway and I've experimented with a range of strategies - the only thing that makes any significant difference (that is under your control) is your speed. Factors like temperature and wind will make a big difference, but you can't control them - other than by choosing to not travel. Trex has done a lot of experiments with charge levels and the use of the "Charge" button - the best he has claimed is an improvement of about 8% in fuel consumption - I've done the same experiments, albeit less formally, and could not detect that much difference.

 

[jaapv]

I just did an 1100 km motorway trip in light traffic (about 100 km secondary road), strong side wind at 90º all the way, heavily loaded with ski box on top. Temp around 15º, in total a 1600 m climb. ACC constantly at 135 kmh, car constantly on charge.
The car did 10,2 km/l. ( approx. 29 mpg). I am quite happy with that.
The battery level varied from full at the start, between halfway and one bar all the way, depending on long inclines up or down, to one bar at arrival at the end of the final steep uphill..