Advise on how to get best MPG?

[suley2]

Hi Guys,

Im new here and just picked up my 2.2 DI-D GX4.

I am still getting to use to it and have downloaded the manual and had a read which usually i dont do.

I have learned allot from it but still have more to understand. My main use for it is to travel from Manchester to Milton Keynes to and back every weekend. Usually i would have driven a Diesel which would use around 1/2 a tank going forward and back so around 28 litres of fuel and that was with a B180 1.6 and when i had a 2.0 it would be a few 33 liters of fuel.

Since my new car is unleaded i thought maybe it would balance off to a diesel ie unleaded is used quicker to diesel however being a phev it should cost wise for the entire journey balance off.

Anyway i put in 25 litres of unleaded on thursday night which gets it to around 3/4 and used the cars charge button to charge it for about an hour on thursday night as i could not charge at home and all the charge points were membership only near me. Friday i work out how to use the B1-5 function and start using that alittle but driving on normal with the air conditioning switched off ie button pressed off.

Anyway friday evening i get to start my drive and as soon as i am out of milton keynes i notice the electric bar is near empty so i press the charge button which i noticed was lowering the mpg which had started at 20 and worked to around 50. So i decided to not charge and thought the manual says on motorways it would self charge the motor and use the fuel so i let it drive until i get to crawly services and remember they are supposed to have a free charge point which i have ordered a card for. I get there hoping maybe another nice user may be able to swipe me in but no luck. I call the number on the pod and they are nice enough to remote unlock it. Anyway it charges to around 75% in 21 mins and then stops. I hop back in and get driving and notice its now using mainly the electric battery and the range was 14 miles. After a while it drops empty and i revert to let the normal motorway charge do its trick.

I get to manchester and notice the range left in fuel is 64 miles to which i think that's not too good, the mpg for this journey average seems to be 43 for 190 miles from Thursday.

I did notice that getting to manchester it did feel like the feet area it was warmer, i know the heating i had pushed off so put it down to engine heat and the fact i only had the heated seat as switched on.

I was wondering can you advise any tips on any modes i can use to get a better mpg on the motorway as i would really like to get to and back milton keynes on the 25 liters i would usually put in a diesel.

I also wanted to know what the difference was between the eco and normal mode as i guess eco would be better to use for local drives?

Any other tips of advice would be great! My plan is to try charge the car today from a normal domestic plug, and then on sunday when i head back use a charge point on the motorway to charge up while enroute and then just before i get to MK to use for the week

 

[Hypermiler]

Hi
Hope you've not been mis-sold the car, as a diesel may have worked out better - presume BIK saving is the biggest draw... It is unrealistic to expect the car to do the same mpg as a 1.6 diesel given this is a 2l petrol SUV with a much heavier body (battery). Motorway mpg likely to be 30-35mpg depending on speed/weather etc.

Anyway. Using electric power on the motorway is a waste of time really. You'll find everyone on here uses the "save" button to make the car use petrol when travelling out of battery range at any speed. You can turn "save" off and glide in B0 down long hills or to use electric in traffic jams.

How far is the journey and how far are you off the motorway at each end? It would usually be best to save your electric power for the non-motorway parts of your journey.

Don't use "charge" - there is no point for the journey you describe.

Reduce your cruising speed to around 70mph (lower if you can) and use cruise control where appropriate.

Make sure your tyre pressures are good - 40 odd.

Use "eco" - reduces the power output so you don't have to be quite as light-footed. I tend to use it all the time, even though I am light-footed.

Have a really good look around this forum to find out what the "charge" button is for, etc.

And what is a 2.2 DI-D :?: - the car is a 2.0 l petrol...

Best of luck!
H

 

[suley2]

@Hypermiler Thanks for your reply.

Its a part of a lease agreement i have, so if i dont like i can change after 6 months, was told about its performance and thought hmm whilst its petrol it may balance off.

I appreciate it is a bigger car so was expecting some trade off in fuel use, it seems in a sense to equal usage of a 1.0 petrol i once drove, half a tank to manchester and half back. As oppose to Diesel which would use a quarter each way. I have just fueled up again 20 liters which seems to get me to 6/8 again.

So i guess am i right in thinking, use Eco mode, use cruise control on the motorway (usually set it to 65-70), hit save all as soon as i hit the motorway so it does not use the electric or let it use it till its low?

From the motorway to home, i use an A road to lead me to my house, is a 12 mile journey with 1 traffic light mid way, speed varies from 50 - 60 along the route once i at the end of the a road its less then a mile to home. Would you suggest i do this leg on petrol or electricity?

 

[greendwarf]

So i guess am i right in thinking, use Eco mode, use cruise control on the motorway (usually set it to 65-70), hit save all as soon as i hit the motorway so it does not use the electric or let it use it till its low?

From the motorway to home, i use an A road to lead me to my house, is a 12 mile journey with 1 traffic light mid way, speed varies from 50 - 60 along the route once i at the end of the a road its less then a mile to home. Would you suggest i do this leg on petrol or electricity?

I'd say Yes - use SAVE when you are driving at a consistent higher speed, so even the A road section would be best on ICE but it depends on if you can charge at home, as even here, if you have battery power available, it would be cheaper to use it. Do you have any EV charging available? If not, then it is difficult to see that this is the car for you unless the BIK saving is the deal breaker.

BTW when in SAVE you get some benefit from Regen via the brakes or deceleration which goes into the battery (unless full) and then powers the car for a while until it drops back to its SAVE level (so saving petrol). However, I prefer the car being in B0 (so only actually getting braking Regen) so that I can coast for "free", especially if there are any significant downhills on the journey.

 

[Hypermiler]

Agree with everything from Greendwarf. Would be better to use electric on the A road than on the motorway, but at 50-60 will still deplete battery pretty quick (I tend to use save if travelling 50+ unless well within ev range). If charging at home, I would aim to save enough to get you from motorway to home but try to stick to 50 if possible. Perhaps the Milton Keynes end of the trip is more suited to using the battery up? For electric use, the slower the better (and for petrol too, as with all cars, of course!).
Cheers
H

 

[suley2]

Thanks guys, charged up a little yesterday and drove a few stops around town today, ev range was 10 miles i did around 7. Charging up now, my plan is if i can get it to charge fully up to 100 then will use it on the A road section or maybe just to get me from home to motorway.

I am heading into London central next week and my plan is maybe i can use the EV as a test to get me there, if gives 14 miles at 75% then a few service stops along the way may get me there with minimal fuel use, i have the time to kill so might experiment

 

[maby]

On long journeys like that, unless you are prepared to do it in a series of short hops with long charging breaks, you are going to do most of it on petrol, so you may as well keep in Save mode till close to your destination. The car handles far better on a reasonably well charged battery - good acceleration and no engine racing up hills. When you are about 25 miles from the destination, turn off save and use up your charge.

It is true that this can be a bit simplistic if the journey is all slow at the start and then motorway speeds till the end, but is it worth risking a sluggish car in order to get three or four more miles on EV on a trip of 200 miles?

 

[tlongdon]

Multiple round-trips of 50 miles, 3 miles Bristol city centre to get to motorway (no traffic issues). Full battery, heating at 20c, no A/C, ACC used on Motorway, Eco Mode. All driven at the same time(s)

ave 70mph = 38mpg
ave 80mph = 32mpg

 

[Paule23]

ave 80mph = 32mpg

That'll be the German Bristol then, as I'm sure no one on this forum would speed, or advertise it!

 

[maby]

Vehicle load also has a significant effect, I think. I've been making the same trip most nights recently to visit a sick relative. It's a round trip of about 60 miles with a significant motorway component and I set out with a full battery. I've been following the philosophy of running on Save till I'm on the return leg. Usually, my wife has accompanied me but last night she had to work late and I did it on my own - in very similar road and weather conditions, I saw a significant improvement in fuel economy (and my wife is by no means overweight!)

This corresponds closely to what I regularly observed with the Prius that preceded the Outlander. I believe it is the case that hybrid vehicles operate at closer to 100% than conventional cars and waste less energy. Our big diesel Landcruiser performs pretty much the same under all conditions of loading - lightly loaded, it is chucking vast amounts of energy out of the exhaust pipe; as the load increases, less of that energy is wasted and more is consumed moving the vehicle. Hybrids are more sensitive to usage since they are not wasting so much energy by default.

 

[tlongdon]

ave 80mph = 32mpg

That'll be the German Bristol then, as I'm sure no one on this forum would speed, or advertise it!

[/quote]

Just outside Baden-Baden (not Bath).

 

[user 258]

ave 70mph = 38mpg
ave 80mph = 32mpg

Hi,
That tallies closely to my 40mpg ish doing a steady 65-70mph ish (not counting the improvement you get with part of the journey being pure EV).
The car is as streamlined as a brick so the slower you can drive the better the economy and battery range. The weight of the car isn't very important when cruising at a constant speed.
Kind regards,
Mark

 

[anko]

I've been following the philosophy of running on Save till I'm on the return leg.

I believe this is a poor decision. Hybrid efficiency depends on the engine being able to use excess power to recharge the battery and then be turned off for a while.

As we presumably know, engines generally run more efficiently as their load increases. Allowing the engine to charge the battery increases its load and therefor its efficiency. To a certain extend "the more the better" applies. For example: if the engine produces 20 kW, 10 of which is used for driving and 10 of which is used for charging, the engine load (while running) is doubled but the engine runs only about half of the time (ignoring electrical conversion losses to keep it simple). But doubling the engines load does not double the fuel consumption (in terms of liters / hour), as the engine runs more efficient. So, the engine runs half of the time with less than double the fuel consumption. So, the total amount of fuel used is less. This is why we have a full hybrid system and not just regenerative breaking (or KERS: kinetic energy recovery system).

The more engine power is sent to battery, the more efficient the engine gets per kWh produced. Until you overshoot, but that won't happen, because normally, the engine load will be far less than what's optimal, even when charging. But the amount of power the engine is allowed to send to the battery depends on the battery SOC. The higher the SOC, the less power can be sent to the battery. So, the efficiency of the total system is less when the SOC is higher.

Now and then, I am using an OBDII scanner to closely monitor fuel consumption and engine power output. What I see is that when the battery SOC reaches about 50%, the engines output in terms of power drops about 10% (at 100 km/h steady driving). And when SOC gets higher it drops even further. I think when SOC gets over 80%, the battery is no longer charged by the engine.

 

[maby]

I've been following the philosophy of running on Save till I'm on the return leg.

I believe this is a poor decision. Hybrid efficiency depends on the engine being able to use excess power to recharge the battery and then be turned off for a while.

As we presumably know, engines generally run more efficiently as their load increases. Allowing the engine to charge the battery increases its load and therefor its efficiency. To a certain extend "the more the better" applies. For example: if the engine produces 20 kW, 10 of which is used for driving and 10 of which is used for charging, the engine load (while running) is doubled but the engine runs only about half of the time (ignoring electrical conversion losses to keep it simple). But doubling the engines load does not double the fuel consumption (in terms of liters / hour), as the engine runs more efficient. So, the engine runs half of the time with less than double the fuel consumption. So, the total amount of fuel used is less. This is why we have a full hybrid system and not just regenerative breaking (or KERS: kinetic energy recovery system).

The more engine power is sent to battery, the more efficient the engine gets per kWh produced. Until you overshoot, but that won't happen, because normally, the engine load will be far less than what's optimal, even when charging. But the amount of power the engine is allowed to send to the battery depends on the battery SOC. The higher the SOC, the less power can be sent to the battery. So, the efficiency of the total system is less when the SOC is higher.

Now and then, I am using an OBDII scanner to closely monitor fuel consumption and engine power output. What I see is that when the battery SOC reaches about 50%, the engines output in terms of power drops about 10% (at 100 km/h steady driving). And when SOC gets higher it drops even further. I think when SOC gets over 80%, the battery is no longer charged by the engine.

All quite true, but "save" is not a pedantic "never use any battery" - if you hit save with a closr to full battery, the charge level drops a bit, then oscillates around. Let it drop to 75% if you like before hitting save, but don't let the battery go flat till you get to a charger - the car runs much better with a reasonable charge level.

 

[greendwarf]

I've been following the philosophy of running on Save till I'm on the return leg.

I believe this is a poor decision. Hybrid efficiency depends on the engine being able to use excess power to recharge the battery and then be turned off for a while..

Which it does in Save when cruising at high speed in my experience :mrgreen:

 

[anko]

I've been following the philosophy of running on Save till I'm on the return leg.

I believe this is a poor decision. Hybrid efficiency depends on the engine being able to use excess power to recharge the battery and then be turned off for a while..

Which it does in Save when cruising at high speed in my experience :mrgreen:

True. But this is not hybrid efficiency

 

[anko]

All quite true, but "save" is not a pedantic "never use any battery" - if you hit save with a closr to full battery, the charge level drops a bit, then oscillates around. Let it drop to 75% if you like before hitting save, but don't let the battery go flat till you get to a charger - the car runs much better with a reasonable charge level.

Of course it is not. But, as I explained, there are several points where the amount of charging changes, one of them being around 50%. So, an SOC of less than 50% will be more efficient than an SOC of above 50%. And apart from that, I believe losses associated with recharging the battery are higher as the the SOC increases. But I am not 100% sure of that.

Would you care to explain why the car would run better with a 'reasonable' charge level (assuming 'reasonable' means more than 30%)? I mean, I understand it will during towing or during high-performance runs, but in such cases, Charge would be a much better option anyway.

 

[jaapv]

Actually there is no difference in performance at all between different charge levels. When the car tells you it has no mileage left, it actually has about 25% of charge in the battery and simply goes into save mode, oscillating the battery level around “zero” . But it still drives the same.
You really have to push it down to about 15% - quite a feat if you manage to do so and I can only recall one or two instances of this being reported in the forums- to get it into energy save mode, which does mean a real performance drop, as symbolized by a turtle on the dashboard display. I think that is what Maby means.
For the rest any sense of difference in the way the cars drives linked to the state of charge is a placebo effect - nothing more.
Oh yes - with the battery completely full regen won’t work - that is true.

 

[anko]

You really have to push it down to about 15% - quite a feat if you manage to do so and I can only recall one or two instances of this being reported in the forums- to get it into energy save mode, which does mean a real performance drop, as symbolized by a turtle on the dashboard display. I think that is what Maby means.

This is what I meant by "I mean, I understand it will during towing or during high-performance runs.". If that was his driving style, Save wouldn't help him to maintain a higher SOC. The fact that he can maintain SOC buying Save suggests he is not pushing it.

 

[maby]

Actually there is no difference in performance at all between different charge levels. When the car tells you it has no mileage left, it actually has about 25% of charge in the battery and simply goes into save mode, oscillating the battery level around “zero” . But it still drives the same.
You really have to push it down to about 15% - quite a feat if you manage to do so and I can only recall one or two instances of this being reported in the forums- to get it into energy save mode, which does mean a real performance drop, as symbolized by a turtle on the dashboard display. I think that is what Maby means.
For the rest any sense of difference in the way the cars drives linked to the state of charge is a placebo effect - nothing more.
Oh yes - with the battery completely full regen won’t work - that is true.

No, that's not what I mean - following some reports here of the engine racing on uphill runs, I paid more attention to the engine note and ran some experiments. I have a couple of quite steep hills that I have to climb regularly around here and I have observed that trying to accelerate up them with a normally flat battery - not right down at the turtle level - can result in engine racing. The same hill with 50% charge is easy. This is exactly the same behaviour I observed with the Prius - trying to accelerate up a moderate hill from a standing start with a depleted battery was a painful experience. It also has an impact on accelerating on the flat - try taking off hard from the lights with a discharged battery and the engine is screaming - do the same with 50% charge and it is purring. The difference between a Prius and an Outlander is that the firmware on the Prius is coded to keep the battery level around 50% on average whereas the Outlander will happily allow it to run down to minimum and stay there. It's idea of minimum is not 0% - true - but if you put heavy load onto a flat Outlander battery, it will race the engine - well, mine at least.