Regenerative Braking

[Mike Watterson]

Some cars even from 2003 (twenty years old) will meet ULEZ. Some new cars won't.
https://www.theguardian.com/environment/...tudy-finds

I don't think a modern EV is simpler than a 1970s petrol car.

I was looking for figures of fire risk and hybrid seem worse than pure petrol or diesel. The EVs are 20 to 10 times less likely to go on fire, but some bad non-EV models the issue is ironically electrics (some Astras)! The figures lack detail so some models or age or cost bracket may skew the figures.

The only car fire I ever personally encountered was my mum's Ford Anglia. Wiring in steering column went on fire. She opened the window and kept going; eventually it burnt out (the wires in the column, not the car). I think my brother replaced the wiring, but he once swapped a Cortina engine because one spark plug was seized in.

I saw a second car burn at a distance. It had been stolen. How many car fires are deliberate? Then there are incidents like Luton car park which are not representative of real day to day risks.

You can get the EV batteries replaced.

[ppppenguin]

I don't think a modern EV is  simpler than a 1970s petrol car.

All modern cars are more complex than 1970s cars. We need to compare like with like - modern EVs are simpler than modern ICE cars.

The Guardian article quoted is somewhat misleading because it focuses mainly on CO2 emissions which are obviously going to be high in big ICE cars. These are addressed, perhaps inadequately, by vehicle tax bands. CO2 emission doesn't cause local problems but obviously contributes to climate chnage. ULEZ is based on NOx and particulates which do cause local problems.

Of course EV batteries can be replaced. At the moment in most cases the cost would put a vehicle BER.

EV fires are much less common, percentagewise, than ICE fires. But they are nasty, burning lithium is hard to extinguish.

[Mike Watterson]

Most Guardian articles involving anything technical are very inaccurate!

Some diesels are likely much worse for particulates and NOx (higher compression) than petrol?

Anyway, it's not simple. I find it hard to believe a Tesla is simpler than my petrol Toyota Yaris. Logically hybrids must be the most complex? However I think an EV ought to be mechanically simpler. Two or four motors (at the wheels, which I saw a design for in 1970s) also would remove more mechanical parts. The differential, drive shafts and gearbox is a lot of mechanical weight and mechanical complexity, especially on 4WD.

You'd think ULEZ is costing every motorist a fortune according to some reporting, but other reporting suggests only about 12.5% are liable. However it seems it will save lives in London.

The remaining pollution issue for EV, apart from manufacture, is tyre particulates. Perhaps there is scope there for improvements too.

[ppppenguin]

Most Guardian articles involving anything technical are very inaccurate!

Most newspaper articles involving anything technical are very inaccurate!

I suppose one should talk of mechanical complexity. A Tesla is a set of computers that happens to run on four wheels! But so are most modern cars.

[Mark Hennessy]

Of course, tax bands have essentially gone for anything made this side of 1st April 2017. The CO2 output only determines the tax for the first year. After that, you pay almost exactly the same as everyone else, whatever your vehicle. The exception being the "luxury car tax", currently an extra £390 if the list price of your car (not the final price you might negotiate) is greater than £40k. With inflation of car prices in recent years, it's surprising how even quite ordinary cars are at risk of falling into that category, especially if you option them up. Note that the £40,000 threshold hasn't changed since inception, so that's yet another stealth tax rise (a bit like the income tax thresholds for higher and additional rates).

I saw that article this morning before work. I had to re-read it now to check it was the same one, because I don't recognise the comments made about it. Nowhere does it say that a new car won't meet ULEZ. I'm not sure where the inaccuracies are, but they are quoting a report, which they clearly cited. I thought it was quite well done, personally. Given their target audience, which isn't us, I generally think their technical articles are good. Much better than most of the press (even the BBC at times). Fine to criticise, but be specific and accurate. E.g. CO2 was better targeted prior to 2017, when the bands affected the cost of VED for the life of the vehicle, not just the first year. The people behind the report - Possible - are arguing for more taxation of big, heavy vehicles, and saying that folk who can afford a massive SUV could afford to buy an EV instead. The newspaper is reporting on that. It's not an opinion piece. The comments here look like they come from people who simply skimmed it.

As is pointed out in the article, CO2 is an environmental issue; ULEZ is a public health concern - in other words, it's to improve air quality rather than drive down CO2 (although that is a useful side-benefit). So that's why it's based on particulate emissions rather than CO2, and that's why old petrol engines are often fine, despite generating more CO2 than diesels of a comparable vintage. I've never liked diesel passenger cars, and won't be sorry to see the back of them - dirty, noisy, smelly things. When cycling, or even just walking through town, you can literally taste them. But petrol isn't innocent - modern direct-injection engines produce higher NOx than port injection. That's why particulate filters are now pretty much standard on petrols.

People have been experimenting for years to make motors in hubs work, but it's much harder than it sounds. Easy to say from the comfort of the armchair, but try doing it, then put it in production. There's lots of information out there about all of this, but just for starters, it's a much harsher environment to put a bunch of electronics and a motor - no cushioning from the suspension, and much harder to give protection from water and other elements. The HV cables have to travel with the suspension and never break, while being protected from road debris, etc. Talking of brakes, they still have to fit there too! And then you've got to sort the handling and ride, given the massively increased unsprung weight. Whereas diffs and driveshafts are proven technology that allow you to overcome all the issues at low cost. Hmm...

Famously they managed to find a Tesla owner who thought he would have to pay ULEZ. I'd have thought that if you could afford a Tesla, you'd be able to do the most basic research, but perhaps not. But now that it's in place, people realise that it's not the big bad bogeyman that certain quarters made out it would be (for obvious reasons that we don't need to stray in to).

[Mike Watterson]

No doubt I misread the article. Unlike the BBC I don't think they block the UK version.

Ah, well a hub motor works in a cycle, but not a great idea in a car or truck, but still you can have a motor system that's closer to the driving wheels. A rear engine with rear drive or front engine with front drive on a regular car does away with the transmission shaft, but you still have the gearbox and differential gears. I wasn't thinking of motors actually in the hubs, though that might work for a city "rickshaw" modern version of Sinclair C5. I remember hydraulic drives were also looked at many years ago.

Ultimately NOx, particulates and CO2 are all environmental and health issues.

I'm totally unfamiliar with UK taxing issues.

Irish tax used to be on Engine Size and at one stage was abolished. There is also Fuel duty and a carbon levy tax on fuel.

Wikipedia has,

As of 2014, annual motor tax rates for private cars on the emissions-based system range from €120 (0 g/km CO2) to €2,350 (more than 225 g/km).[1] Tax for motorcycles varies from €35 to €88.[2]
Vehicles 30 years old or more qualify for "vintage" motor tax status - a special low rate of €26 per year for motorcycles or €56 per year for all other vehicles.

But the annual NCT (like MOT, but different) measures other emissions too and has fail limits.
I just paid €76 for three months for the Yaris (2008).

[Mark Hennessy]

Don't worry - my comments about VED were in reply to Jeffrey's points. I should have quoted, but was in a hurry to leave.

Since getting home, I've been reviewing my YouTube history, looking for a video I saw which explained the issues of hub motors in cars really well. Giving up now, as it must have been longer ago than I thought. It's definitely not impossible, but it'll be a while before it's in mass production, if ever. Many challenges.

As it is, some EVs (e.g. Rivian) have 4 motors, but mounted inboard. That's a half-way house, but it's debatable what you gain. The losses in a differential driving half-shafts aren't terrible - are they worse than the penalty of the extra weight of another motor? From what I've seen, 4-motor setups are more about power than efficiency. Personally, I'd rather focus on the latter - we all know that EVs can be crazy-fast, but that gets boring quickly - efficiency and range are what matters to most users of public roads.

For 4WD, I haven't seen one that uses front-rear prop shaft and differential like ICE - they all use separate front/rear motor/final drive assemblies. Probably because the battery is in the way! Most seem to only use 4WD for tearing away from a standstill, and drop back to one (usually the front) for normal driving. So they are quite a lot simpler than conventional 4WD cars. I'd wager there's a lot more moving parts in the simplest ICE engine than any EV motor, and of course the "gearbox" is only a fixed gear and differential, as there's no need to shift gears. The trouble is, it's easy to forget how complicated ICE engines and drivechains are, even in a relatively simple thing like a Yaris, because we don't strip them down any more. The last engine I worked on was an 8 valve from 1984, and I only needed to strip and rebuild the head - that was complicated enough, though it was my first (and only) time getting that involved. I've been watching quite a few teardown and restoration videos of engines over the years, ranging from simple to high-end, and they are so much more involved than an EV motor. Especially if you are replacing rod and main bearing shells. Kudos to the people doing that! Really, the complexity now is in the electronics and software, plus the cooling system. In terms of parts count alone, the cooling system is probably the most involved part of an EV, with lots of hoses, pumps and valves. Tesla have done a good job of integrating lots of these parts into one fairly large single component with the so-called "Super Manifold". Of course, it's not just about cooling the batteries, motor and inverter; the same system provides the cabin heating/cooling via a heat pump (and can heat the batteries to condition them as needed before driving and charging). Is that system more complicated than an ICE vehicle with air-con? Not sure, but certainly in a similar ballpark...