Are new petrol engined cars really any greener?

[Sp!ke]

This got me wondering.

I appreciate that diesel technology has come a long way over the recent years but how about petrol engine technology?

My old workhorse is now over 18 years old, it is fuel injected, has a catalytic converter and at MOT time, the emissions are still so low I was told last time that it would pass even the very latest MOT emissions test. It also returns over 30mpg on my daily commute across the congested roads of west London.

Would a new 2.3 litre petrol engined car of a similar size really be significantly kinder on the environment or more economical?

 

[The Boss]

It will be kinder.. but significantly kinder.. doubt it...

new engines - More fuel efficient, for sure! but towards the environment, i dont think there is much in it..

Its some of the other brands that never got the cars quite right that are spewing out crap into the atmosphere.. and more so, the likes of older tatas in Indian/Africa that i think are causing the enviromental issues..

Get them off the road!

 

[crockers]

It will be kinder.. but significantly kinder.. doubt it...

new engines - More fuel efficient, for sure! but towards the environment, i dont think there is much in it..

Its some of the other brands that never got the cars quite right that are spewing out crap into the atmosphere.. and more so, the likes of older tatas in Indian/Africa that i think are causing the enviromental issues..

Get them off the road!

Rather an arrogant view........ how are the locals going to afford the newer much more expensive cars.

Its all well complaining about India, Africa etc polluting the world - but all they are trying to do is raise their living standards to something akin to ours in the 50's 60's - so if we don't like the way they are doing it we ought to perhaps offer help and assistance rather than rhetoric.

But then where is the money going to come from?

 

[KillerHERTZ]

Drive behind any 1980's or earlier car and you will know how far filters/cats etc have come.

Main problem with new cars are the weight, although engines are more effient the cars mass has creased by huge amounts.

New Fiesta for example, slightly shorter than a W202!

 

[grober]

Modern petrol engines can be significantly more economic then the older designs with corresponding lower CO2 figures The obvious ones are ones with direct petrol injection smaller capacity coupled to turbo charging .Many also employ variable inlet dynamics and camshaft profiles to improve low speed torque. These engines exhibit high torque characteristics over a wide engine rev range-- in other words very like modern turbocharged diesel engines. The downside is increased complexity which may mean expensive repairs in the long term--a bit like modern turbo charged diesels.
You still can't beat the sheer thermal efficiency of a high compression ratio diesel tho.
Here's an example from a rival manufacturer.http://www.audiworld.com/news/06/paris-audi-18tfsi-engine/content.shtml

or Mercedes new CGI engines http://www.worldcarfans.com/109060419755/mercedes-adds-new-engines-to-c-class-blueefficiency-range

 

[Sp!ke]

new engines - More fuel efficient, for sure! but towards the environment, i dont think there is much in it..

Heres the thing though. Is a new 2.3L petrol engined Mercedes really noticeably more fuel efficient than its 20 year old predecessor?

I filled up yesterday and noted that my average mpg for the tank was 32mpg for mostly rush hour driving across the capital.

If I look up the official fuel consumption of say a brand new CLK200, (a smaller lighter car with a smaller engine), the combined cycle gets a claimed 32mpg and the urban cycle 22.4mpg. There doesn't seem to be an awful lot of progress going on in the engine efficiency department over the last 20 years.

 

[The Boss]

Heres the thing though. Is a new 2.3L petrol engined Mercedes really noticeably more fuel efficient?

I filled up yesterday and noted that my average mpg for the tank was 32mpg for mostly rush hour driving across the capital.

If I look up the official fuel consumption of say a brand new CLK200, (a smaller lighter car with a smaller engine), the combined cycle gets a claimed 32mpg and the urban cycle 22.4mpg. There doesn't seem to be an awful lot of progress going on in the engine efficiency department over the last 20 years.

When i have looked at the new models, for example, the newest s class vs the previous generation, vs w140 vs w126, u notice a definetly improvment in feel, control, power delivery. Full efficient wise, i never really saw any benefits.. the biggest being when they introduced the v8 half cylinder shut offs on motorways..

Generically, from an 18 yr old car, to a new one, there is efficiencies ofcourse, but i think its more in the way the power of the engine is harnessed, so its got alot to do with whats going on around the engine...

I have always enjoyed the additional refinement of the new cars, just not the build quality...

like an old brick built house compared to new modular partition built houses.. both can lived in efficiently and effectively, but one just feels more solid that the other..

its an interesting topic though..

 

[Sp!ke]

I think we can all agree that newer cars are more refined.

The question is are they truthfully any greener?

When you factor in that my old girl is still going strong, is using its original catalytic converter, original exhaust, original disks, original everything really, could the same be expected of the latest generation of cars and if not, would the shorter life and therefore extra manufacturing costs outway the seemingly minimal improvements in economy?

Everywhere else in life we are told that we should recycle and reuse. Yet in the car industry we are told to scrap and buy new. Are we being completely misled at such a high level?

 

[TonyVianoAmbiente]

If I look up the official fuel consumption of say a brand new CLK200, (a smaller lighter car with a smaller engine), the combined cycle gets a claimed 32mpg and the urban cycle 22.4mpg. There doesn't seem to be an awful lot of progress going on in the engine efficiency department over the last 20 years.

That's at least partly the fault of safety legislation, which has resulted in much heavier cars, and emissions legislation, which has reduced pollution but at the cost of increasing fuel consumption.

These factors have at least partly outweighed any improvements in fuel efficiency.

 

[timskemp]

Are the words "who cares, I like my cars" appropriate here?

My old 2.0 petrol montego was lighter and used less fuel than our current 1.6 V50, in face my old 2.8 XR4x4 wasn't much worse.

 

[corned]

I think KHz has hit the nail on the head. Yes, engines themselves are indeed greener - probably quite significantly so.

However, this is completely negated by ever-increasing safety legislation which means that the car bodies are now far heavier than they used to be, even in recent times. I was startled to read somewhere that the new Jaguar XJ, with it's lightweight all-alloy body, whilst being significantly lighter than the competition, still weights in at something like 2.3 or 2.4 tonnes wet! That was Range Rover territory not so many years back.

 

[timskemp]

Corned - the way I read it the current jaguar XJ starts at about 1750kg, 40kg lighter than the previous one, and significantly lighter than the S / 7 / A8

 

[renault12ts]

Greener? Yes. My first car...renault12ts... and second car...Morris Minor...both got 30mpg from 1286cc and 1100cc respectively. My 3226cc CDI averages above 37mpg with 50 mpg being seen on long runs.

 

[corned]

Corned - the way I read it the current jaguar XJ starts at about 1750kg, 40kg lighter than the previous one, and significantly lighter than the S / 7 / A8

Ah - OK. I must have read the maximum take-off weight then! It is still heavier than our old all-steel XJ of 1995 vintage though.

 

[Mactech]

Are new petrol cars greener than the ones they replace?
I think we are missing a couple of parts of this question.

Firstly yes! The new cars are cleaner and better despite being mostly heavier because we (or legislation) now demand safer cars.

Secondly I can't see how it can be overall greener if we take in to account the energy used to develop and build the new cars and the material usage.

Thirdly: Depends very much on the fuel we now use. The 2nd generation bio fuels are about 50% greener on a 'well to wheel' basis that traditional fuels.

Not a simple question, and I’m sure statistics can be warped to prove whatever we fancy depending how ‘global’ we want to make the terms of reference.

Reminds me of the energy crisis when lots of motorsport events were cut in length by up to 25% completly ignoring the fact that the race fuel usage was just 1% that of those coming to see the events!

 

[Sp!ke]

Ah - OK. I must have read the maximum take-off weight then! It is still heavier than our old all-steel XJ of 1995 vintage though.

I doubt it. The old 1995 XJ used very heavy materials and thick body panels.

Todays cars might be bigger but they are consistantly lighter.

>Mactech When you say Bio fuels, are you referring to Diesel fuel rather than Petrol? If not, I'm not aware of any Petrol Bio fuel being used to any extent.

 

[Sp!ke]

Greener? Yes. My first car...renault12ts... and second car...Morris Minor...both got 30mpg from 1286cc and 1100cc respectively. My 3226cc CDI averages above 37mpg with 50 mpg being seen on long runs.

We are talking about PETROL engines. Try to keep up at the back.

 

[Mactech]

>Mactech When you say Bio fuels, are you referring to Diesel fuel rather than Petrol? If not, I'm not aware of any Petrol Bio fuel being used to any extent.

If you fancy some reading:

http://www.bentleymotors.com/media/med/Libraries/1/Bentley_and_Biofuels_FINAL_FlexFuel_Version.pdf

It's petrol Jim, but not as we know it...

 

[Sp!ke]

From what I read, this is not being mass produced and would still need mixing with regular fuel.

I'd like to keep the debate about what we have on offer now rather than what may or may not be produced in the future.

Besides, I thought the whole biofuel thing was largely being dismissed as doing more harm than good.

 

[The Boss]

dismissed as doing more harm than good.

yup.. it smells.. lol