RE: Hybrids are the 'next diesel': Tell Me I'm Wrong

[Evanivitch]

rdjohn said:

A great article

Plug-in Hybrids should be tested for emissions as if the were simple ICE's. That is how they are used most of the time.

Utter tripe.

[LordTwaddle]

All I say is this:

Manufacturers should simply make an all electronic car within their engine/model line ups. For example: Fiat. They should make their TwinAir 2cl, an all rounder 3cl, a powerful 4cl (Abarth) and an electric plug-in version. Same goes for Mazda: the 2 range should be a 3cl, their 1.5l 4cl and an electric power unit.

It gives people the choice between economic petrol, powerful petrol or electric. Everyone's happy.

[kambites]

The problem with that approach is that basing an EV and ICE powered vehicle on the same shell significantly compromises one or both vehicles in terms of packaging.

[howertings]

I'm very late to the party on the whole discussion over ev emissions, but fwiw here's my back-of-a-fag-packet calculation for typical UK conditions:

Scenario 1:
I buy a Tesla Model S (85) and plug it in at any time of the day or night during 2016.
Then based on an average of 308g/kWh over the whole year for electricity production (ref. http://electricityinfo.org/real-time-british-elect... and an EPA consumption rate of 24kWh/100km (ref. https://en.wikipedia.org/wiki/Tesla_Model_S, US EPA ratings, which is probably more believable than the NEDC fairytale) then (as a good first estimate but ignoring some minor losses such as charging losses) the average emission of my car over the year is
0.24 kWh/km x 308 g/kWh = 74 g/km

Scenario 2:
I buy a BMW i3 (94 ah bev) and plug and plug it in at any time of the day or night during 2016.
Again based on an average of 308g/kWh over the whole year for electricity production and a consumption rate of 29kWh/100mi (ref. https://https://en.wikipedia.org/wiki/BMW_i3) then the average emission of my car over the year is
0.29 kWh/mi x 0.6214 mi/km x 308 g/kWh = 56 g/km

Scenario 3:
I buy a 2016 Prius VVT-i Active (not a plug-in).
Quoted emission rate is 70 g/km (ref Pistonheads buy/sell section, some random car on sale)
Conversion factor of 1/0.67 to convert offical fuel consumption to real world consumption (ref. http://www.honestjohn.co.uk/realmpg/toyota/prius-2... the average emissions of my car is
70 g/km * 1/0.67 realmpg/fairytalempg = 104 g/km

Scenario 4:
My lotto numbers pop up and in my daze I buy a Porsche Panamera Turbo SE Hybrid. However in a fit of eco-remorse I commmit myself to running it on battery power alone (christ, how do i believe the lies I tell myself??).
Quoted emission rate is 16.2 kWh/100km (ref. http://www.porsche.com/international/models/paname...
Conversion factor of 50km/38km fairytalerange/realworldrange (ref. http://insideevs.com/2018-porsche-panamera-turbo-s...
Again based on an average of 308g/kWh over the year for electricity production, average emissions for the car is
0.162 kWh/km x 50/38 realworld/fairytale x 308g/kWh = 65 g/km

I could keep going on and on, but the pretty obvious conclusion is that (like for like) electric cars emit less CO2 than ice cars (even hybrids), small light cars emit less CO2 than large heavy cars (even ev's). Also, the panamera hybrid is low in emissions if I can run it on battery power alone during my daily commute. And if I have to satisfy my petrolhead impulses at the weekend and use it in full-on mode instead of driving my dirty old petrol V6 then it still emits less CO2 in total. Eco-Result!

Edited by howertings on Tuesday 21st March 21:11

[RobDickinson]

Uh..

Given electric motors sare incredibly efficient.. and the Panama hybrid is 2300gks +

How it does 16kwh per 100km compared to the small light i3 at 29kwh or the similar sized and slightly lighter tesla of 24kwh? Given the tesla has a better Drag coefficient too (24 vs 29)?


Magic?

[Evanivitch]

LordTwaddle said:

All I say is this:

Manufacturers should simply make an all electronic car within their engine/model line ups. For example: Fiat. They should make their TwinAir 2cl, an all rounder 3cl, a powerful 4cl (Abarth) and an electric plug-in version. Same goes for Mazda: the 2 range should be a 3cl, their 1.5l 4cl and an electric power unit.

It gives people the choice between economic petrol, powerful petrol or electric. Everyone's happy.

Hyundai are doing something similar with the Ioniq.

[herewego]

Gorbyrev said:

98elise said:

Gorbyrev said:

....Firstly, compression ignition is an elegant and efficient means of propulsion for cars....

It isn't. ICE's need clutches and gearboxes to make them work for required speed/torque range. They need a load of additional ancillaries to keep cool, start etc and they bleed energy and they cannot recover kinetic energy without an additional ancillary system. The are also overly complicated.

Electric motors are 98% efficient, have one moving part (+ the bearings), and can provide the entire range of torque/speed requirements. Electric motors (especially 3 phase) are fantastically simple.

if it were not for the energy storage issues of electricity then the ICE would have been dead years ago.

Couldn't argue with your defense of electric propulsion but your last point makes the case. In terms of carrying a certain energy density power source to yield a certain range diesel is remarkable. Its power reserve is also rapidly replenished. All stating the obvious but none the less true for all that. Until cell and/or capacitor technology catches up it will retain those advantages.

It's a moot point though if we're not taking pollution and CO2 emissions into account.

[herewego]

Evanivitch said:

rdjohn said:

A great article

Plug-in Hybrids should be tested for emissions as if the were simple ICE's. That is how they are used most of the time.

Utter tripe.

It seems people are buying them for the BIK and congestion charge alone and not actually plugging them in. There's even a thread somewhere of people asking why they should bother plugging in as it only saves a few quid. How many of such people there are we don't know. The only justification really is that the tax breaks encourage plug in technology. Somehow we need to ensure they are plugged in or the tax breaks should be clawed back.

[peklim]

I have a X5 PHEV & it has saved me a fortune in petrol. I buy petrol every couple of months now as opposed to at least weekly before, which admittedly was with a E61 M5.Buying a PHEV & not plugging it in,ideally at both ends of the journey,makes no sense.

[Evilex]

otolith said:

Evilex said:

otolith said:

Evilex said:

Going back to first principles? No. Walking, for example, is still free.
However, Governments of all political persuasions like to accrue and spend revenue. In this specific case (motor vehicles & VED), the mechanism is already in place and tolerated/viewed as a necessary evil that facilitates our use of the road network. How much of that revenue actually goes into road construction/maintenance/improvement is, at best, unclear. Nonetheless, it is likely that the road network maintenance cost would be the primary reason cited for the retention of VED after the decline of ICE road vehicles.

VED is a small slice of the cake, though. The big issue is fuel duty, and that mechanism will become redundant with a shift to electric vehicles.

Which is why I suggested that a big hike in VED (or a realignment) would be likely (in order to compensate for the reduced fuel duty income) in my earliest post.

I don't think that's a likely measure. Such a large hike (we're talking a factor of six) would be a very hard sell politically. Applying it only to electric vehicles would be counter-productive to the desire to shift cars to electric power, shifting taxes from use to ownership is counter to policy objectives to discourage driving and making multiple car ownership prohibitively expensive will discourage families from enabling everyday electric car use by owning a second ICE car.

While in this transitional phase as we move (glacially slowly) from ICE through Hybrid powertrains to all-electric, I wouldn't advocate applying any single tariff to any one kind of vehicle exclusively. Nor do I favour taxing ownership over use. I do, however, think that the government will use VED realignment to balance the books in the short term. That, and the new first-year tax that's been introduced seems to signal their train of thought.

Edited by Evilex on Wednesday 22 March 11:45

[otolith]

That will work in the short term, we're still only looking at a small proportion of EV/PHEV cars. I think if things accelerate, they will need to come up with another plan.

[buggalugs]

RobDickinson said:

Uh..

Given electric motors sare incredibly efficient.. and the Panama hybrid is 2300gks +

How it does 16kwh per 100km compared to the small light i3 at 29kwh or the similar sized and slightly lighter tesla of 24kwh? Given the tesla has a better Drag coefficient too (24 vs 29)?


Magic?

Yeah that Porsche number makes no sense at all

Also why apply fairytale conversions to some of the cars but not others?

[Evanivitch]

herewego said:

Evanivitch said:

rdjohn said:

A great article

Plug-in Hybrids should be tested for emissions as if the were simple ICE's. That is how they are used most of the time.

Utter tripe.

It seems people are buying them for the BIK and congestion charge alone and not actually plugging them in. There's even a thread somewhere of people asking why they should bother plugging in as it only saves a few quid. How many of such people there are we don't know. The only justification really is that the tax breaks encourage plug in technology. Somehow we need to ensure they are plugged in or the tax breaks should be clawed back.

I forgot everyone lived in London again, my mistake.

Or perhaps because even without the plug-in part, it's still more efficient than a "simple ICE".

[Wills2]

herewego said:

Evanivitch said:

rdjohn said:

A great article

Plug-in Hybrids should be tested for emissions as if the were simple ICE's. That is how they are used most of the time.

Utter tripe.

It seems people are buying them for the BIK and congestion charge alone and not actually plugging them in. There's even a thread somewhere of people asking why they should bother plugging in as it only saves a few quid. How many of such people there are we don't know. The only justification really is that the tax breaks encourage plug in technology. Somehow we need to ensure they are plugged in or the tax breaks should be clawed back.

Yep it's a farce, everyone I know who has one did it for one reason to save money on BIK has nothing to do with green credentials perceived or otherwise.

They know the official MPG/Co2 data in rubbish and don't care so long as they save money.

[NJH]

Same reasons why people who don't need pickup trucks buy pickup trucks, they can put it through the business as a utility vehicle when really for 99% of the time they just need a car to get around in.

[raspy]

steve1386 said:

Ive said:

I am driving a 2nd gen Prius as my daily.
Same argument as for the Honda. the hybrid part makes a small petrol engine very efficient and clean.
It provides the same torque and power as a small turbodiesel (120Hp), about the same mpg, but without the emissions.
By the way, the 2nd gen Prius battery pack weights 43kg, so about twice the weight of a lead starter battery of any bigger diesel engine, e.g. 72Ah of a BMW 6 cylinder engined car.

I'm sorry, but a Prius will never achieve the same real word economy as a diesel, nor will any hybrid. If the battery is fully charged, then they are only useful in short, stop-start city traffic.

Take one on a motorway for a long journey and you'll be lucky to see 40mpg.

On top of that you have to tell someone you drive a Prius!

I beg to differ. I went round the M25 last week and despite lots of overtaking trucks I still got 60mpg with my Gen 4 Prius. Not sure where your figure of 40mpg came from.

[havoc]

raspy said:

I beg to differ. I went round the M25 last week and despite lots of overtaking trucks I still got 60mpg with my Gen 4 Prius. Not sure where your figure of 40mpg came from.

It depends on your M-way cruising speed and also how much accel'n / decel'n you need to do.

Small-engine hybrids (and small-capacity diesels) tend to have shorter gearing (so operate at higher revs at e.g. 80 / 85mph) and need more throttle load to achieve sufficient accel'n in give-and-take driving.

Both of these have an adverse effect on economy. A larger-capacity diesel will typically have longer gearing so 80mph in 6th may be outside of the turbo-range, and it'll intrinsically have more torque so will not need so much throttle to achieve the desired acceleration.


(In other words, hybrids are excellent at town work (PHEVs esp.) and good at lower-speed longer-range driving (PHEVs less so as the range between stops increases), small-diesels are excellent for mid- and long-distance lower-speed driving, big diesels are (comparatively) better for higher-speed / longer-range work)

[buggalugs]

havoc said:

raspy said:

I beg to differ. I went round the M25 last week and despite lots of overtaking trucks I still got 60mpg with my Gen 4 Prius. Not sure where your figure of 40mpg came from.

It depends on your M-way cruising speed and also how much accel'n / decel'n you need to do.

Small-engine hybrids (and small-capacity diesels) tend to have shorter gearing (so operate at higher revs at e.g. 80 / 85mph) and need more throttle load to achieve sufficient accel'n in give-and-take driving.

Both of these have an adverse effect on economy. A larger-capacity diesel will typically have longer gearing so 80mph in 6th may be outside of the turbo-range, and it'll intrinsically have more torque so will not need so much throttle to achieve the desired acceleration.


(In other words, hybrids are excellent at town work (PHEVs esp.) and good at lower-speed longer-range driving (PHEVs less so as the range between stops increases), small-diesels are excellent for mid- and long-distance lower-speed driving, big diesels are (comparatively) better for higher-speed / longer-range work)

I really don't understand all these people chiming in with their theories on why a Prius gets bad mpg, despite every single person with first hand experience stating that they don't.

[RobDickinson]

The original mk1 prius if not in urban cycle was pants, but that was a long time ago

[kambites]

RobDickinson said:

The original mk1 prius if not in urban cycle was pants, but that was a long time ago

Indeed. People have long memories when it comes to finding an excuse to still dislike things.