The diesel controversy

Tetra-Ethyl Lead requires the addition of a lead scavenger, commonly Ethylene Di-bromide to stop excessive buildup of lead oxides in the combustion chamber and to ensure the removal of the lead into the exhaust stream, this combines with combustion water / steam in the exhaust to form an acid.

Remove the tetra-ethyl lead from the fuel and you can remove the scavenger, and thus remove the exhaust corrosion problem. A petrol vehicle with a catalyst will, by the ongoing inherent chemical reactions have considerably more 'water' in the exhaust stream than non-cat equipped vehciles.

The actual fabrication and construction of exhausts has changed a bit over the years but fully aluminised exhausts were actually standard fitment to things like the mini metro in the early 1980's, from the removal of lead to standard cat fitment in the early 1990's the level of corrosion on exhaust has dropped considerably, fatigue failures are in my experience now far more common than corrosion.

Also fitment of cats was nothing to do with stopping people 'gassing' themselves with the CO. They orginated in the country where you can easily buy a handgun at the local supermarket, which is claimed to be far more effective and less painful than choking on exhaust fumes.

PS Aftermarket brake pads have to meet a certain (high) percentage of the braking capability of the orignals in order to be allowed on sale anywhere in the EU  (ECE R90) .  

In Germany everything you fit to the vehicle must be TUV approved in order for the car to remain legal for road use.   In the UK we are slightly more lax but ignorance of the construction and use regulations does not absolve you of prosecution.  Removing a DPF (or a catalyst) makes the vehicle non complaint for road use.  This is an absolute and is not open to any interpretation.

Edited By Martin 100 on 15/05/2017 22:25:26

This might be tosh, as it is a 'someone told me', but I'm given to understand that the imposition of catalysts by bureaucrats killed stone dead the development of stratified charge engines, which could have achieved the same or better results. Don't legislate the means, legislate the outcome, but they never learn.

Really? If true that is against EU rules on free movement of goods and services. TUV are just one of many test houses. What is required is CE marking for those items that are covered by EU Directives requiring it.

Russell

Compliance by CE marking for 1:1 direct replacements is enough, but for anything not a 1:1 replacement, involving some degree of modification, or deviation from the orignal type approval is not.

As an end user you can fit what you like sourced within Europe or elsewhere, but you cannot use it on the road in Germany, nor will a vehicle pass the equivalent of the VOSA MOT test if you do not have the supporting documentation. CE marking in this instance is worthless without a proper paper trail and without an ABE or a TUV reference the CE marking by itself is not enough.  

(this is in reference to motorbikes but cars are treated the same)

ABE and TÜV certificate of conformity – how to maintain a clear overview

It's very effective proactive enforcement of their equivalent of the construction and use legislation to the actual vehicle fleet on the road. It's also ensuring continued type approval compliance regardless of in which country it was first achieved.

It's not a barrier to free movement of goods and services.

Edited By Martin 100 on 16/05/2017 12:06:00

Martin 100 said:

A petrol vehicle with a catalyst will, by the ongoing inherent chemical reactions have considerably more 'water' in the exhaust stream than non-cat equipped vehciles.

Really? Perhaps you might explain the reasoning behind that statement? As I see it, the water in the exhaust is either tthat which goes in with the combustion air (a relatively small but variable amount) or from the hydrogen in the fuel. Catalytic converters only convert a very minor amount of hydrocarbons to water and carbon dioxide, thus only a tiny extra amount of water would be generated, if any, by a vehicle with a catalytic converter.

The differences in fuel molecular make up would certainly change the proportion of water (shorter carbon-carbon chained hydrocarbons contain a higher percentage of hydrogen), but that has naff all to do with the catalytic converter? Further, as cars are generally more fuel efficient these days, the gross exhaust emissions will be lower - again, nothing to do with the cat. Enter alcohols,added to the fuel, and that changes things too, but nowt to do with the cat.

As regards internal exhaust corrosion, the removal (at the refining stage) of sulphur componds (more noticeable for diesel fuel, of course) and conversion of NOx to nitrogen means there should be far less acidic radicals in the exhaust stream. That a cat needs to run hotter than a non-catalytic exhaust (if it gets up to temperature - see post on cold cats/short journeys) combines to give less sulphuric and nitric acids being inside the exhaust. So there is one reason why exhausts last longer these days. I would think the higher exit temps of exhaust gases, since unleaded fuels were formulated, has more bearing on the problem, than the actual catalytic converter.

I look forward to your explanation for the above statement.

I suppose it depends on what Martin meant by 'considerably more' and not done it yet means by 'tiny'.

Wikipedia has average figures for pre-cat emissions from the average American car in 2000 of:

Hydrocarbons (ie un-burnt fuel) 35kg per annum

Carbon Monoxide (Poisonous) 261kg pa

Nitrogen Oxides (Poisonous) 17.3kg pa

The US emissions targets issued in 2004 called for reductions to:

Hydrocarbons 0.91kg pa

Carbon Monoxide 43kg pa

Nitrogen Oxides 0.64kg pa

The catalyser burns an extra 35kg of un-burnt fuel producing quite a lot of water in the process. So Martin is 'right' if he means extra water per year and not done it yet is 'right' if he means extra water as a percentage.

Dementia is much more common than it used to be. Apparently it is possible for particulates to migrate direct from the nasal cavity into the brain; they are not filtered by the lungs. A link between the amount of particulates in the brain and dementia has been demonstrated. I don't think anyone's proved that pollution causes dementia, but post-mortem results are certainly suggestive.

Dave

I have a stupid thing going on with my insurer at the moment.

I am converting my Vito taxi (includes 6 removable seats and windows) to a motorhome. The level of conversion I want to do would qualify in the US as a 'Day-van', but not as a full motorhome conversion, because I can use the vehicle for other things. So, I discuss the mods I want to do with my current van's insurer's and they say 'Not enough of a conversion to qualify as a motorhome, so we won't touch it as we're motorhome insurers.'. Then we go to a van insurer & get the response 'Are you going to modify the vehicle in any way? If yes, go away.'. I ask for the level of modification that counts as modifying the vehicle. The response: one M4 screw hole in the floor pan is enough to invalidate the insurance.

I've done stress analysis on aeroplanes & have had CAA accreditation and won't do anything stupid. Apparently technical competence & facts are entirely irrelevant. Probably because the person assessing the work is technically incompetent.

So, to progress, I ask if I can attach any mods I make to the cargo attachment points in the van. The reply 'That would then be cargo in the van and you can do what you like. It won't be insured, but it won't invalidate your insurance, either.'. Ahh. A way forward. Only the insurer said 'But we won't insure you.' 'Why not?!?' says I. The insurer's reply: 'Because you are obviously wanting to do something out of the ordinary and we don't insure risks like that." . They've told me it's OK, and then it's not in 3 minutes.

Makes you sick.

Rant over

Richard.

Edited By richardandtracy on 16/05/2017 16:43:00

OK Dave,

Let's just assume petrol is octane (clearly not, but an average hydrocarbon).

From that data, each car produced 5.600 tonnes of CO2 (ignoring the minor constituents)

If pure octane C8 H18 (RMMof 114), that equates to 5.6/114*18 tonnes of hydogen

= 0.88 tonnes .

That hydrogen combines with oxygen to form water (H2O has an RMM of 18), so 0.88/2*18 = 7.9 tonnes. And you or m 100 is suggesting that water from 35kg of hydrocarbons (equivalent to 50kg of water if it were octane - but it won't be) is a "considerable" increase? That amounts to a 0.63% increase. Hardly significant. I just asked my wife what she thought would be a "considerable increase" and she replied "more than 20%".

Of course those results are hypothetical and I would guess the 50kg water equivalent for 35kg of HC is 'vastly' overestimated! Catalytic converters were around long before year 2000, so real results would be very different - but no considerable increase in water emissions whichever way you want to look at it. Still hoping m 100 will explain his statement.

Planet over heating - Diesel addresses that.

Planet over populated..................

:D

Diesels been addressing that too hasn't it Nick?

Planet over populated

Don't worry, nature will sort that out ie wars, famine, disease, floods etc

Richard + Tracy,

what about insurance as special ......

I run a five seater VW,T4, actually first reg in Holland.....you should have been there trying to insure it....."they" the morons said as the vehicle was not a model supplied to the country I want to insure it in so they couldn't insure it.......... Reason being they could not offer a satisfactory repair because the parts are unavailable from the general dealer.....then I explained about other imported models of cars say from Japan.......think I just pxxxed em off and they gave me it.....bloody pen pushers......

and if it has a bump over a grand it's a write off anyway !!!!!!!!!!!

how about strapping ur furniture down with tie straps to the original fittings then ur legal.....

sorry it doesn't help much but I know how you feel......prats...Clogs

What makes a 'motorhome' is set out here:

www.ukmotorhomes.net/motorhome-faqs/16-motorhome-mots

My recollection is that basically this means there must be beds and table (which may fold away or be removable for stowage but are part of the vehicle - i.e. not just a folding picnic table)

Neil

You must also inform the DVLA for change of use from van to camper.

Martin P

Once done you can drive at 70mph on the motorway, instead of 60.

Logical, eh?

Neil

Once done you can drive at 70mph on the motorway, instead of 60.

Vans can drive at 70 mph on motorways anyway, so no change there ?

Nigel B

Edited By martin perman on 23/05/2017 07:41:09

They can and do, but they aren't supposed to.

Neil

They can and do, but they aren't supposed to.

**LINK**

HMG say otherwise - look at the column "Goods vehicles (not more than 7.5 tonnes maximum laden weight)" which shows motorway speed limt as 70 mph. This is the same as "Cars, motorcycles, car-derived vans and dual-purpose vehicles", "Motorhomes or motor caravans (not more than 3.05 tonnes maximum unladen weight)" , "Motorhomes or motor caravans (more than 3.05 tonnes maximum unladen weight)" and "Buses, coaches and minibuses (not more than 12 metres overall length)" - all are 70 mph on motorways.

Dual carriage ways & single carriage ways are another matter, but for motorhomes "not more than 3.05 tonnes maximum unladen weight" sets the limits, not maximum permitted weight.

Nigel B