Re: Motorbikes '16 times worse than cars for pollution'
 

As far as I'm concerned, the article lost all credability as soon as I noticed it was from the Guardian. Still churning out pompus left wing hippy crap as usual.

I believe the question is one of "environmental footprint"



"Guardian fails omission test"

Re: Motorbikes '16 times worse than cars for pollution'
 

Hmmm...I'm not quite sure where Jordan* sits on this one.

But I think he feels that the article is lacking in veracity.


*Flaming Squiller - slightly to the right of Genghis Khan.

:lol: :lol: :lol:

Hmmmm, too much scope for ill-informed politically motivated partial truths when it comes to the subject of "green" vehicles.

Just my 2p (or Eu0.02), though I confess I'm not really that up to date on bike emissions.

There's a fundamental difference between CO2 (which is fuel consumption by another name and not a "regulated pollutant"), and the "regulated pollutants" i.e. CO, HC (all types of hydrocarbons), and the various oxides of nitrogen NOx.

In Europe there are no regulations governing CO2, it's just measured and then used as a tax generator.

For bikes the big change following the EURO-1 standards (1999) came at April 2003 with tighter limits on CO and HC, hence the introduction of fuel injection and PAIR systems, some bikes having oxidation catalysts.

The next big step is 2006, some slightly different test procedure details and tighter emission levels, which really mean 3-way catalysts/lambda sensors will be pretty common. I think there's a staged test requirement going into 2007 depending whether the bike is a carry-over or a new model, not too sure on that.

Anyway, it's not surprising bikes in use today are "dirtier" than cars, that's regulations for you. Just like we in the UK were very slow off the mark in reducing car emissions thanks to one Mrs.M.Thatcher who was told the "lean-burn" would be the saviour of the world so no need to synchronise UK emission standards and practices with Europe, USA, Japan, Australia, Canada, etc etc.

After 2006 bike (>150cc anyway) emissions will be more in the theme of cars, though not strictly equal
http://www.unece.org/trans/doc/2002/...-44-inf06e.doc

There are hints of what's to come though regarding in-use compliance and/or prohibiting alteration of emission critical items, which would basically put the kybosh on aftermarket cans etc.

There's no getting away from it, pre-2003 bikes were pretty filthy things.

.....just don't start me on diesel regulations......... :evil:

But according to this, maybe we ought to be revving our engines at traffic lights in order to save the planet:

http://www.guardian.co.uk/science/st...672446,00.html

:?


(Though as it came from the Guardian, it might not be considered rodent-friendly :lol: )


.

So I now have a green reason for keepin gthe Spit on the road? Woohoo!

Q about the lean burn engines though - I always understood that lean burn engines are better than a normal engine chocked with a cat anyway? (And you don't have the at to manufacture / dispose or produce evil fumes when they break down?)

Could be wrong here though...

As long as you don't actually want to breathe aswell. :?

On lean-burn vs. stoichiometric+3 way cats, it's a complex issue and a lot of modern (= last year or 2) generation petrol engines actually run something of a combined regime.

True "Lean-burn" petrol engines still need cats, it's just that in theory the CO+HC is oxidised in the cylinder down to very low levels, the problem is that under load the NOx levels become very high and with excess O2 in the exhaust a "reducing" (opposite of oxidation) cat can't get the nitrogen and oxygen apart. To get lower "raw" emissions of NOx you end up using exhaust gas recirculation (EGR), which is also almost universally used on modern diesels for the same reason, and in a petrol engine the driveability suffers at the high EGR levels required (20%+), and high EGR plus high air dilution makes for big stability issues.

EGR systems are a mechanical headache too, with control valves and coolers etc.

Direct injection gasoline, especially the stratified charge versions, try to address some of these problems by burning the petrol in a stoichiometric region surrounded by excess air. It's all a bit witchcrafty.

Latest generation engine management and wide range lambda sensors can allow all sorts of strategies that weren't possible a few years ago.

It's a bit of a myth that cats reduce performance significantly. Early on (1970s and 80s) that was true, but specific output (both power and torque/BMEP) of modern petrol engines is higher than it's ever been. Technology marches on.

I really wouldn't go along with the suggestion that it's kinder to the planet to keep on running old bangers. One old "A" series engine with a well worn SU carb will probably produce as much noxious pollution as 500 new cars.

The ageing diesel fleet (i.e. vehicles typically 10yrs old) is the big problem in cities with NOx and particulates. The fleet needs to be replaced ASAP.

I know the Spit is evil, I set it up that way. I'm allowed 3.5% on the emisions and it's set to 3.5% - much healthier for the engine, and much better performance.

Plus of course every 7 years or so it needs a respray using power, solvents etc etc etc etc.

But it's still nicer than any new car (to me anyway).

Stu

Absolute nonsense. When was the last time you saw a cyclist on the road :wink:

Re: Motorbikes '16 times worse than cars for pollution'
 

Yes, Yes I agree why don't he tell us how he really feels about it!
:lol: :lol: :lol: