Impossible Advertising

[anko]

The plug in hybrid fuel consumption is calculated over an imaginary trip of 75 km.

According to Wikipedia (so by no means infallible), the European fuel economy test is only 11 km long. The only reason I can see why the PHEV wouldn't give a 'zero' figure is that it includes a brief spell at 120 kph.

The hybrid fuel consumption may be obtained over an 11 km long distance. True. But this is done with a depleted battery. The plugin hybrid fuel consumption is derived from the hybrid fuel consumption as:

In general: ((0 * EV range) + (hybrid consumption * 25 km)) / (EV range + 25 km)
For the PHEV: ((0 * 52 km) + (5.8 l/100 km * 25 km)) / 72 km = 1.9 l / 100 km.

The 25 km is prescribed by the test and suggests how far you need to drive to the next charge station after depleting the battery.

So, roughly plug-in fuel consumption is one third of non-plug in consumption. But this applies to our PHEV. With a smaller battery, the factor would have been bigger. With a bigger battery the factor would have been even smaller.

 

[ChrisMiller]

Thanks, anko, that's very useful information.

 

[Bilbo59]

Looking forward to the day when they do real tests which do not require complex calculations. At least 300k on mixed roads or a test track set up to reflect real world driving. For hybrids they could do battery full starts and battery empty starts on various road types. Whatever was required to reflect what real owners driving in Urban, Rural and Motorway conditions would experience.

At the moment the figures do not reflect the reality of what many owners will experience. Those prospective purchasers who are technical may appreciate this more than others who are not. The tests should be set up to help the latter group and ensure that no one is misled whatever their reason for buying the car.

For the record, I did a fairly complex analysis to calculate predicted tax savings/running costs. It hasn't been far off in practice with mpg running at 49.9 over 18,000 miles of mixed urban, rural and motorway driving. And yes, I have the electric costs too and know the cost per mile compared to my last car which averaged 27.7mpg over 90,000 miles.

I did not believe the advertising except for the headline electric range (yes even with all the caveats Mitsubishi put in the small print) which I did and this has proved to be inaccurate. I also wasn't aware that the engine would run every time I wanted to heat the car and it was cold outside. If I knew then what I know now, I would not have bought the car even though it has met all the tax/cost benefits I expected.

 

[greendwarf]

I also wasn't aware that the engine would run every time I wanted to heat the car and it was cold outside. If I knew then what I know now, I would not have bought the car even though it has met all the tax/cost benefits I expected.

Is this for a Gx3 without the electric heater?

 

[ChrisMiller]

Looking forward to the day when they do real tests which do not require complex calculations.

That's not possible. No single number (or three numbers, as the tests are currently run) can reflect the many and varied styles and routes of every driver. At least by having an official lab test, you can produce numbers that are comparable between models*, even though they are likely to exceed the results we experience in real world driving. So if diesel model A has test results of 70 mpg and model B gets 60 mpg, you know which has better fuel consumption (for a typical driver on a typical route - if you're a taxi operator in a big city YMMV, as they say).
* Assuming there's no VW-style 'cheating' going on.

 

[Bilbo59]

I also wasn't aware that the engine would run every time I wanted to heat the car and it was cold outside. If I knew then what I know now, I would not have bought the car even though it has met all the tax/cost benefits I expected.

Is this for a Gx3 without the electric heater?

No it has an electric heater. See the discussion on Pure EV and also the discussion on stopping ICE for heating. They are focussed on making the car's characteristics more user friendly for those owners that would like less ICE when the battery has sufficient capacity to be used (I am one of those).

 

[Bilbo59]

Looking forward to the day when they do real tests which do not require complex calculations.

That's not possible. No single number (or three numbers, as the tests are currently run) can reflect the many and varied styles and routes of every driver. At least by having an official lab test, you can produce numbers that are comparable between models*, even though they are likely to exceed the results we experience in real world driving. So if diesel model A has test results of 70 mpg and model B gets 60 mpg, you know which has better fuel consumption (for a typical driver on a typical route - if you're a taxi operator in a big city YMMV, as they say).
* Assuming there's no VW-style 'cheating' going on.

I think that they could get closer to having fewer calculations if a longer distance in controlled conditions was used. The car magazines seem to manage it pretty well so perhaps officialdom could learn from them and then apply the controlled conditions necessary for credibility and comparability. The longer the tests the more accurate they should be. A longer test proved relevant in the case of VW. For example, a controlled test over 1000km would be more accurate than over 100km. It may not be practical but it would be nice to see how the results reflected owner's experiences.

Hybrids and pure EV should also have very specific and separate tests from normal cars.

 

[maby]

....

I think that they could get closer to having fewer calculations if a longer distance in controlled conditions was used. The car magazines seem to manage it pretty well so perhaps officialdom could learn from them and then apply the controlled conditions necessary for credibility and comparability. The longer the tests the more accurate they should be. A longer test proved relevant in the case of VW. For example, a controlled test over 1000km would be more accurate than over 100km. It may not be practical but it would be nice to see how the results reflected owner's experiences.

Hybrids and pure EV should also have very specific and separate tests from normal cars.

I think hybrids should be subject to two tests - one being the full test that is applied to standard cars and the other running over a shorter test track that is more compatible with the EV capabilities of the car. While it is true that some PHEV owners such as me do drive it well outside its EV design envelop, few people are going to buy a large car costing over £35k and only use it for 20 mile daily hops, so we need to understand its performance under all circumstances.

 

[Carnut]

Maby said:-few people are going to buy a large car costing over £35k and only use it for 20 mile daily hops, so we need to understand its performance under all circumstances.
Well I did!. My average daily mileage is probably about 10miles.
But I bought it for
1.two large dogs and I don't like the modern trend of 'slopey-back' estate cars.
2. My old bones can't be doing with low slung cars.
3. I was 'suckered' in by the ridiculous advertised 'up to' (I'm not that daft) consumption. I did not expect it to do anything like 148mpg, but I certainly thought it would be better than it is.
Now there are mumblings about excessive road tax for diesels, I am having to think again about what the pHEV replacement is going to be.
4. I thought the 'tech' might be amusing.