How often do GPFs need to regenerate to burn off accumulated particles. I’m assuming much less often than diesel vehicles. Happens - an active regen that is - in my diesel about every 500 miles but often at the wrong time which means I need to drive about for a bit to let it finish.

The site looks like the former Redcar Steelworks - a huge remediation job after years of steel making. At least it will be a good investment for Teesside, it badly needs it after years of decline with closures that have ripped the soul out of Redcar and other surrounding local communities. The nearby Wilton Complex lit at night was supposedly the inspiration to Ridley Scott for the cityscape for Bladerunner. I digress!

What is the enforcement threshold for speeding in the US? I assume it varies from state to state? In the UK policing guidelines suggest an enforcement threshold of 10% +2mph. So on the motorway it’s not unusual for people to set their cruise at 78mph even though the limit is 70mph.

The London Underground is similar. There’s always a hazy mist over the platform. I’ve also blown black snot out of my nose onto a tissue. Amazing though how it’s taken, like the best part of 100 years to realise this. I haven’t seen any headlines yet about how bad it is to be on a train platform when a diesel loco is ticking over. On the platforms of Birmingham’s New Street Station you could cut the fumes from a Virgin Cross Country diesel train with a chain saw. No one speaks about this though because those in local office are too busy obsessing about how streets can be altered to create congestion, supposedly because this makes people throw their car keys in the bin and take the [non existent] bus instead.

There’s a lot of irony in a train being transported by road. The Kelpies on the other hand are brilliant sculptures. Worth coming off the M9 to explore than just pass by.

Over 10 years ago, the UK government said that all new build housing would be zero carbon. It never happened. New houses still have gas boilers and are poor to adapt to air or ground source heat pumps because they leak heat like sieves. So how can we be so confident that a ban on the sale of new ICEs will be in place if it could be similarly dropped quietly? By then, if drop in synthetic petrol or diesel using captured airborne CO2 becomes a market reality, will a ban on really be necessary? I’m not convinced it will if emissions have improved.

How on earth did we cope back in the days when brake pads were made with asbestos?

Yes it is, quite common now.

... meanwhile in the UK some roundabouts are being replaced with traffic signals, or have become signalised themselves to become. Frustratingly this often happens when a road to expressway standard meets a motorway e.g J28 of the M1 where the A38 meets the motorway with a roundabout above the motorway which becomes overloaded, so it is signalised, then it becomes overloaded again. Instead of biting the bullet and designing free flow intersections, exit slip roads (off ramps) are widened to make larger queues fatter, but then it’s not long before the queuing back up onto the main carriageway of the motorway again. In the UK more money is spent bodging and tinkering than fixing problems like this properly. And they are called improvements. The occasional junction has been fixed. J19 of the M1, where the M6 begins had the A14 expressway terminate with a nasty dumbbell junction when it was built in 1990. Goole Earth shows how this has now been fixed. No more 4 mile queues to the roundabout now it’s been replaced with direct connector slip roads.

..or recycle the CO2 to synthetic fuels to use in existing cars.

You can't run the existing ICE fleet on electricity, so developing greener drop-in fuels has to be a good thing. Scrapping vehicles prematurely through scappage scheme, to me is a waste. We need effort to go down the Co2 capture and convert route. I don't see why this cannot sit alongside electric technology constrained by the availability of rare earth resources. Horse for coures and that kind of thing.

OK, so what about the other 60%, or is that in the "too difficult" pile.

I use Shell V Power Diesel in my Euro6, as it has a blend of GTL synthetic diesel and supposedly more cleaning additives. It's more expensive, but in the belief that less soot will load the DPF. I haven't noticed any active regeneration side owning it over the last 6,000 miles. MPG has improved slightly over that time with a cleaner engine.

We could put part of the blame on high fuel taxes which has encouraged people to switch to diesel to eek more likes out of a gallon, to offset the cost. I would be no coincidence that many developed countries outside the EU happen to have better air quality levels because more people use petrol, as it's not taxed so highly.

$20? I spent £80 filling my Audi A6 with diesel on Monday night, admittedly with V-power diesel, which works out at $7 per US gallon. I can get 550-600 miles on that amount though.

If it's anything like the UK it will be the extortionate costs of car insurance that will put young people off driving and hence getting a licence. You're looking at at least £1,000 or more to be insured to drive at a young age, because of risk.

If you live in a country like the UK, where the cost of fuel is $7 per gallon, then driving a diesel becomes an attractive choice, and indeed this is a big reason why I have a diesel, because I rack up 24,000 miles year commuting. It would be so much less if I could afford to live close to work, but that would be futile, anyway as my wife commutes the same distance in the opposite direction and there are no jobs closer. This relates to a huge issue about a massive disconnect between having homes close to where people work, which is the elephant in the room when it comes to the question as to why so many people commute. It's either that or be out of work and a home, so it's a no brainer, unless of course you have the nice luxury of being within spitting distance of mass transit, or a short walk to work. Lucky for some I guess. I did myself. I used the Metro, but I had to move from where I used to live to after losing my job. Hence! No surprises that in countries where fuel is half the cost, gasoline is more popular and less polluting, locally at least. But in countries where fuel is highly taxed, you find ways of getting round it. Hence, diesel. Yes, Electric could be option, but that will have to wait before I can afford one, as my budget for car buying sits at $7k. It would also have to be something that can get me from the UK to France on road trips - 700 miles on a tank of diesel in a day and with a boot big enough for camping gear or capable of bring 100 litres or so of wine home, or seat 4 adults with luggage for trips to places such as Bruges like we did last summer. I try to do my bit though. I use V- Power Diesel nitro for its GTL blend of synthetic diesel - it's more poke and less smoke. And over 50 mpg is possible in my 2006 Audi A6 2.7TDi on long runs. Where I commute, air quality isn't an issue, so I don't have any shame at all of driving a Euro IV emission standard vehicle.

Unfortunately I don't have the luxury of living close to work because of the huge difference in housing costs. So I commute 35 miles instead. Hence , I tactically travel in early to beat the traffic and go for a nice 7-mile walk along a canal and through parkland. It's a nice way to start a day and beats doubling my commuting time sitting in rush hour traffic. I feel fit too!

The less poor will drive cars that are older that will get less mileage that more recent models. The greater cost will eat into any ability to save money for a better mileage replacement. In Europe highly taxed fuel means more people drive diesel engined vehicles, because you get much better mileage. I can get over 50 mpg (imperial) in my Audi A6 2.7 TDi Avant which makes $8 per imperial gallon easier to live with. Mind you I use V-Power diesel which is more like $9 per gallon. The petrol equivalent might manage 35mpg on a similar run. Now you have the green lobby with a vendetta against diesel - the same lobby that wanted and still want higher fuel taxes which resulted with more people resorting to diesel power. A spectacular own goal in that context. Yes we have electric vehicles now but for a person like me who likes road trips to France or to visit family and friends range still needs to improve and costs need to drop. I'm the sort of person who avoids finance and pays cash for my cars and saves money in the meantime for the next car when needed. Hence, bought my 2012 Audi for £5k four years ago and will get another good four years out of it. For that sort of money you'd be lucky to buy electric. Anyway, with PHEVs the quoted mileage is a scam unless your the sort that gets away with running on electric mode most of the time. Otherwise 100 mpg is a myth for long distances.

Be careful about increasing fuel taxes. It's no coincidence here in the UK that the massive surge in diesel ownership happened as fuel taxes increased under the fuel duty escalator to some 57p per litre. With air pollution now big issue, the idea that fuel taxes would benefit the environment has backfired badly. The highly taxed rate of fuel is THE reason I bought a diesel to keep a lid on fuel costs, as I have to commute 35 miles to work. My wife commutes 30 miles in the opposite direction, so moving is not an option. Neither are EVs, as we often need to cover greater distances. We drive to France for holidays, or parts of the UK for work, camping trips, or to see family. Remember also, fuel taxes are regressive, hitting the poorest hardest. So don't expect to see more wealthy folk ditching their SUVs in a hurry. It will put low paid people into fuel poverty, especially if they have no alternatives. The negative s outweigh the limited benefit in my view. To be cynical, it's a stealth tax and nothing more.

Is it really a good thing to invest a lot of public subsidy on something that will have a indiscernible impact in the great scheme of things. Is taking an older car off that could have a good few more years of service remaining a sustainable practice if the emergy and materials needed is going to more than offset any savings in lower fuel consumption. Sorry for being cynical but is this to benefit air quality or the auto industry? For my part I have a 16 year old car 1.8T Passat with 215,000 miles which suits my driving routines in a way that an EV cannot meet. In europe where fuel prices are acopalyptically high (in a US consumer's view), it's effecient enough for me to keep it going even though it runs on petrol (gasoline). I can get 45mpg on a good run to work even though it is rated to be 34mpg on the EU Combined Cycle, as I have looked after it and know how to drive effciently without driving like funeral director.

Thomas If I wanted a car for short journeys I would get one that is a lot older and has lost much of its depreciation already. I've always had older car that I have paid for in cash. I've had an 1997 Audi A6 2.5TDi cost £2,700 and lasted 7 years before I let it go to a good home for £200. I also have a 1999 Passat that I bought 11 years ago that cost £4,500 and could fetch a optimistic £750 if I sold it tomorrow. I still have it with 210,000 miles done and I expect to still have it when it reaches 250,000 miles. Even though fuel is £5.50 per gallon (or about a good $8 per US gallon) its a damned sight cheaper than running a LEAF and I get to go onlong roadtrips quite regularly which is a bonus, as I have friends and family in distant places.

The driver demographic will be quite narrow, mainly people who commute a regular daily milage that is well within EV range but adds up to high weekly milages and saves a lot in cost on petro-fuels. Very few people will buy an EV if they do limited milages as the little money saved in fuel will be completely wiped out by depreciation costs. Equally no-one will by an EV if driving patterns include longer even occasional road trips. So naturally the mileage of Leaf drivers will be more. That all aside, I think the biggest disincentive about the Leaf is the fact that it is ugly, but maybe that's more to do with the fact that Nissan have got into a bad habit of making ugly cars, likelwise with Renault who have been at it (uglification) for a lot longer. Look at the Juke as a good example or the Renault Vel Satis. The Tesla at least looks quite normal. I see them regularly in my neck of the woods.

People buying electric vehicles will do so for a reason: they do a lot of miles through a regular commute but comfortably within the range that an EV allows. I cannot see people buying an EV if the few miles and hence little saved in fuel is overwhelmed by the cost of depreciation, and that applies equally in Europe than it does in the US. That's why the mileage is higher. It attracts a certain driving demographic who typically drive a daily milage witin range that adds up to more than the average for the whole driving population. In short damed lies and statistics.

These are the unintended consequences of high fuel taxes.