Question for ya-Diesel vs. Gas

I was talking to a friend yesterday about the emissions from a diesel versus the emissions from a gas vehicle. You know when your driving along and you see those big puffs of black smoke come from diesel vehicles, well it seems to me there would be alot tighter emission standards on deisels than on gas powered vehicles. But here in Texas it's just the opposite. You have to pass an emissions test on almost all newer gas vehicles, but on diesels you just gotta pretty much honk the horn and flash the head lights. Can anyone answer this for me or at least enlighten me a little. My friend suggested that maybe the combustion process of the fuel being different may make the diesel have less pollutants, but as for me, I doubt it.

Not sure what the rules and reg's are like in texas but in Europe any modern deisel engine doesn't puff huge clouds of black smoke, in recent years they have tightened up a lot on emisions laws, and most modern engines we have use common rail injection which helps both emisions and fuel econemy, for instance one of the cars i own is a nissan micra 1.5dci (1.5 turbo diesel with common rail injection) this is capable of over 100 mph and if driven carefully i have had it recording almost 90 mpg.

Gas engines probably do emit less polution? but the problem here in the UK is that the goverment has started to slowly increase the amount of duty they take on this fuel which is making it less atractive and will make it take longer to recover the engine conversion cost's.

My boss's wife has a deisel jetta which he said gets 51 mpg and I thought that was great, but 90 mpg , WOW. We need more of those on the road.

You have to drive like an old granddad to get that sort of econemy but financially it pay's for itself

No wonder I only get about 14 mpg.

Originally posted by opinionsarefree
No wonder I only get about 14 mpg.

lol my other car does around 4 mpg with the speedo usually half way around lap two

Originally posted by opinionsarefree
My boss's wife has a deisel jetta which he said gets 51 mpg and I thought that was great, but 90 mpg , WOW. We need more of those on the road.

One has to wonder why in the US we do not even have the option of this kid of fuel economy. Even the hybrids don't get that much.

Originally posted by Relentless

Originally posted by opinionsarefree
My boss's wife has a deisel jetta which he said gets 51 mpg and I thought that was great, but 90 mpg , WOW. We need more of those on the road.

One has to wonder why in the US we do not even have the option of this kid of fuel economy. Even the hybrids don't get that much.

almost all of the engines i've seen in US cars have been above 5 litres in size which obviously doesnt help? you then have to take into acount things like fuel injection systems and gearing (i'm not sure what they use in the US)