Hybrid MPG

[mrloudly]

It's time hybrid manufacturers started quoting "Equiv. MPG" figures in their advertising! It's not right that Hybrid vehicles using massive amounts of fossil fuel
produced electrical energy, are allowed to quote high MPG figures. Take the new Porsche 918 Spyder, 4.6-Litre V8, two electric motors, sub 3secs 0-60
and claiming 94mpg... Whilst it is probably true on petrol consumption, the true equivalent energy usage is plainly much higher!
This needs changing as IMHO it is misleading advertising and makes single fuel vehicles look a lot worse than they are!

[kambites]

It's nothing to do with the manufacturers and everything to do with the EU. The manufacturers wouldn't be allowed to use a more realistic test even if they wanted to.

I think trying to fudge "equivalent MPG" figures would be a bit daft, but they definitely ought to use the average CO2 cost of producing electricity for any battery charge present at the start of the test to alter that figure. And maybe also publish a "fuel pence per mile" figure which includes both electricity and petrol used at current rates (which obviously this would have to be updated regularly), as well; or maybe just publish the amount of pre-charge present in the car at the start of the test and let people work out its cost themselves.

Edited by kambites on Monday 30th July 08:46

[thinfourth2]

But the vast majority of hybrids don't use any electricity from the mains there is no way to charge up the current prius

Only plug-in hybrids use mains electricty and the only one on the market today is the vauxhall ampera


But i agree there should be a altered test for plug-in hybrids as in run the battery down till its 25% charge and then do the normal rolling road test

[mrloudly]

Good point Thin

It's a transfer of energy thing, and we all know there are losses whenever this process occurs.

http://www.euractiv.com/energy/analysis-efficiency...

Quite a different picture when you take this sort of thing into account... I doesn't stop with the power station losses either, chargers produce heat
and there's more losses there...

[thinfourth2]

mrloudly said:

Good point Thin

It's a transfer of energy thing, and we all know there are losses whenever this process occurs.

http://www.euractiv.com/energy/analysis-efficiency...

Quite a different picture when you take this sort of thing into account... I doesn't stop with the power station losses either, chargers produce heat
and there's more losses there...

But if you take into account all the plant food gas into account for electricty then you must do the same for a fossil fueled car. As the petrol doesn't magically appear in the petrol station.

[kambites]

thinfourth2 said:

But if you take into account all the plant food gas into account for electricty then you must do the same for a fossil fueled car. As the petrol doesn't magically appear in the petrol station.

Energy usage for finding, extracting, transporting, refining then re-transporting road fuel are fairly significant. You've got to either take the "full" costs for both fuels or for neither.

With plug-ins, you also get into the rather complicated question of how we should be generating electricity.


I don't think the current tests particularly favour non-plugin hybrids. Under normal driving, I seem to get a current generation Prius closer to its official figure than a diesel 3-series.

Edited by kambites on Monday 30th July 09:31

[mrloudly]

" Energy usage for finding, extracting, transporting, refining then re-transporting road fuel are fairly significant"

As they are for coal as well... Then, according to the above global figures, it only yields 31% of it's potential as useable electrical energy.

I guess we'll never know the truth...