Fuel economy on the motorway

[Markd75]

Hello all

I have purchased a 2015 Outlander PHEV. I seem to go through an awful lot of fuel. I have been reading through some of the posts on here and to be honest, my he\d is fried with trying to work out the best way to operate the car. When the drive battery is available to help the petrol engine, the car is incredibly efficient, but this only last a short while and then I appear to be driving a bit of a gas guzzler!

I just did a good long run on the motorway as I needed to do a course for work and took the opportunity to measure miles driven and fuel used. The journey stated with a full drive battery. Most of the drive was on the motorway at 70mph with some in town at the other end. 219 miles motorway and 28 miles in town. I was conscious to accelerate smoothly and used regen braking to try to claw some battery power back.

I used the charge button for 45 minutes before I got to the other end so that I would have some drive battery for EV driving.

After filling up when I got home, I travelled a total of 247 miles (397.5 km) and used 48.4L of petrol. Unless my math is flawed, this works out at 12.18L/100km (23.1 miles/ imperial gallon) Is this normal? It seems terribly inefficient for a car that is meant to be good for the environment.

Any tips or advice on how to improve this would be greatly appreciated.

 

[jaapv]

Yes, that is about the long and short of it. You are driving a two-tonne car with a Cw value that is about the same as Canterbury Cathedral and a considerable front surface using a petrol engine at speed.
Most of us do a bit better, but you are not quite used to the car yet. I usually get about 10-9.5 l / 100 km on long motorway runs, driving about 130/140 kph.
It may be that conditions were adverse, Headwind, using the heater or airconditioning, tyre pressure , hilly roads, etc. may push the value down.
Driving style is of great influence, maintaining a constant speed and feathering the accelerator helps a lot. The Power dial is quite informative, the deeper into the green, the better.
My advice on long runs is not to worry about fuel consumption, but to enjoy the exceptional smoothness and silence of the car.
The technology is aimed at pottering around in the suburbs, making use of the space, high driving position, maneuverability, 4WD, electric drive, and so on.

 

[user 3575]

This might help we are achieving similar figures.

www.greencarguide.co.uk/car-reviews-and-road-tests/mitsubishi-outlander-phev-4wd-2019-review

 

[jaapv]

Do you really trust an article that begins by "an engine that is mated to an automatic transmission" which does not exist... :? ?
Falsus in uno, falsus in omnibus. :ugeek:
The figures in the article are for the newest type, which has a tweaked drive train, and, I can attest, is a different feeling car from the 2015 model.

 

[ThudnBlundr]

I get 35-40mpg on a long run in ours, with ACC set to 70mph. It is very sensitive to speed though: I used to set it at 72mph (which is an actual 70mph on the GPS) and it was noticeably worse.

IMHO you can get too hung up on trying to get the best out of the car. TBH I've not noticed a significant change using CHRG on the motorway and using EV in town. Simply sticking it in 'D' seems to work fairly well

 

[user 3575]

So that is 2 of us an earlier and a later model achieving similar figure to both the road test and real life. The Outlander PHEV owners towing with the 2 litre models are achieving around 22/26mpg towing in the UK in the warmer weather.

Jaapv you are achieving 28/30 UK mpg driving at 80/86 miles per mph

So no even with my very limited experience with the PHEV your figures are low

 

[kpetrov]

The car is not done to be economical on long commutes at high speeds.
On 5 to 10 times the battery range I am doing ~8L/100km at 100kmh. As the speed increase the consumption jumps significantly.

 

[user 3575]

The car is not done to be economical on long commutes at high speeds.
On 5 to 10 times the battery range I am doing ~8L/100km at 100kmh. As the speed increase the consumption jumps significantly.

Converting 8L/100km = UK 35 mpg@ 60mph

 

[greendwarf]

23 mpg does seem low if you were doing no more than 70mph. Although I don't monitor usage very much, as I rarely travel long distance but in the UK I seem to get 30+ and even in France at 80mph (with an empty roof rack!) it was around 27mpg.

What I have found is that Cruise Control is better (and more economical) than your right foot at maintaining a steady speed.

 

[AndyInOz]

Note also that a sticking parking brake can also significantly reduce fuel economy.

 

[littlescrote]

Note also that a sticking parking brake can also significantly reduce fuel economy.

This ^

Not just the parking brake it's all brake calipers in general that are often seized and dragging due to lack of use and being of poor quality. Give them all a good service by stripping down and lubricating sliding surfaces etc. If a rear caliper is seized on the parking brake mechanism, very common, you will have to replace at your cost even though it is a known failure and there have been recalls because of it.

 

[EssexBoy]

......and lubricating sliding surfaces....

But not all sliding surfaces ! :twisted:

 

[littlescrote]

......and lubricating sliding surfaces....

But not all sliding surfaces ! :twisted:

Yes, all sliding surfaces - NOT friction surfaces