are there incentives to buy hybrid lexus

E92

Capt'n Midnight wrote:

If you are interested in the environment just get a diesel.

I disagree. Its a well known fact that diesel cars cause local pollutants, and have a negative impact on local air quality. Why does Ken Livingstone make such a fuss about the air quality in London, even though he has the so called congestion charge? In Germany, where diesels are very popular, though in my experience, they're only in the ha'penny place compared to Portugal/ France/Italy, the government made a concerted effort to get the car companies to fit particulate filters as standard. Yes, I accept that they are infinately better than before, but don't ever forget that if a petrol and a diesel do exactly the same mpg, the diesel produces 13% more Carbon Dioxide per kilometre. The reason why diesels produce lower emissions in areas such as CO2 and CO is because of a complete lack of investment in petrols. Companies that invest in petrols can easily get low CO2 emissions; look at the soon to be launched BMW 118i; 47.9 mpg average, 140 g/km CO2 and the 320d; 49.6mpg average, 153 g/km CO2. I know I'm not comparing the same series car, but the 1er and the 3er are as close as you'll get:D

Capt'n Midnight wrote:

Most hybrids are not much greener to run than a diesel, especially when you take into account the fuel used in the refinery to crack/reform petrol.

If you take into account the enviromental impact of the batteries / electronics etc. then most hybrids are worse than diesels.

I couldn't agree more, but anything that stops ecomentalists from complaing about cars has to be welcomed, if and only if for that reason. Hence why I said what I did about the good oul fashioned petrol.;)

JHMEG

E92 wrote:

look at the soon to be launched BMW 118i; 47.9 mpg average, 140 g/km CO2

For a bog standard petrol engine that mpg figure for the 118 sounds a little too good to be true. A quick bit of googling reveals 38.7mpg on the combined cycle. The CO2 emissions are equally as poor @ 176g/km.

http://www.carpages.co.uk/bmw/bmw_new_118i_04_09_04.asp
http://uk.cars.yahoo.com/car-reviews/car-and-driving/bmw-118i-1004437.html

unkel

JHMEG wrote:

that mpg figure for the 118 sounds a little too good to be true

Yes it sounds very optimistic. Any links to back that up, E92?

Capt'n Midnight

E92 wrote:

I disagree. Its a well known fact that diesel cars cause local pollutants, and have a negative impact on local air quality.

Diesel didn't have lead. Also much of the smokiness is a thing of the past. Cyclones and filters have reduced the particle emission. The quality of the fuel is improving and bio-diesel is supposed to be better.

but don't ever forget that if a petrol and a diesel do exactly the same mpg, the diesel produces 13% more Carbon Dioxide per kilometre. The reason why diesels produce lower emissions in areas such as CO2 and CO is because of a complete lack of investment in petrols.

Oh dear.
Diesel is denser than petrol so more carbon per litre.
For the same weight it has more carbon and less hydrogen.
Not sure about the CO since lean burn petrol have up to 1% CO in the exhust ( maybe before the cat )
Because diesel is denser it has a higher energy density than petrol, so you would expect a better mpg from it. BUT the higher compression in a diesel engine is one of the reasons it's a more efficient heat engine in theory and in practice. Efficient in the sense that it uses the maximum % of the energy in the fuel. You will never make a petrol engine as efficient as a diesel engine, even using variable timing and all that good stuff. But you can do that with a diesel too

For large ships you have a choice of Diesel or Steam, trucks, locomotives, tractors, trawlers, construction equipment etc. are almost all Diesels. Considering how much cheaper petrol engines are there must be a reason, and it's only been like that for ages. With locomotives they generate electricity and use that to power electric motors on the wheels, and even still no one's thinking about building petrol trains.

Also it takes more energy (more CO2) to make petrol than diesel. Even Biodiesel is easier to separate out than the energy costs associated with distilling out ethanol , again more efficiencies

Petrol engines are cheaper, lighter, easier to start and more responsive. But electric motors have even better power to weight ratios and so easy to start and can be super responsive, only problem is the battery is heavy.

E92

unkel wrote:

Yes it sounds very optimistic. Any links to back that up, E92?

This one, Unkel http://www.bmw.co.uk/bmwuk/about/news/0,5126,1156___co-181209342,00.html tells us about the 118i, which as I said before, is soon to be launched i.e the 1 (to pardon the pun) they'll sell you at the moment does the figures JHMEG mentioned.
and this one http://www.bmw.co.uk/bmwuk/pricesandspecifications_technical_specs/0,4639,1156_149349913__bs-Mw%253D%253D%2540bb-M0xJ%2540bm-WjNTQg%253D%253D,00.html tells us about the 320d.

Capt'n Midnight wrote:

For large ships you have a choice of Diesel or Steam, trucks, locomotives, tractors, trawlers, construction equipment etc. are almost all Diesels. Considering how much cheaper petrol engines are there must be a reason, and it's only been like that for ages. With locomotives they generate electricity and use that to power electric motors on the wheels, and even still no one's thinking about building petrol trains.

Also it takes more energy (more CO2) to make petrol than diesel. Even Biodiesel is easier to separate out than the energy costs associated with distilling out ethanol , again more efficiencies

Petrol engines are cheaper, lighter, easier to start and more responsive. But electric motors have even better power to weight ratios and so easy to start and can be super responsive, only problem is the battery is heavy.

Thanks for that Capt'n Midnight, for putting that much right in my mind anyway.I thought this was a forum about cars:D . Look, I wasn't, (and I'm sorry if this comes across as arrogant, I'm not meaning to be ) trying to say that petrol is always better than diesel, on any grounds. Of course nobody is trying to make a petrol powered train, that would be sheer lunacy. All I wanted to say was that for cars, if they're serious about the enviornment, that with high levels of investment, there's no reason why petrols couldn't offer fuel economy figures close enough to diesels. In my example of the 118i/320d, even though the diesel had almost 2 mpg of an advantage, it still produced 13g of CO2 more for every kilometre travelled than the 118i. If you travel 20,000 km(roughly 12,000 miles) a year you would save the earth of 260kg of CO2 with the 118, even though more fuel would have been used. The reason why diesels are better with heavy vehicles is because of all the torque a diesel has, which is a force that produces rotation i.e makes a vehicle move in the first place. I know its theres more to it than that, but lets not go there:) . That and the fact the even the highest revving diesel can only go to around 5,500 rpm; some petrols are only starting to get into their stride at 5,500 rpm. The importance of such a low rev limit is that theres less wear and tear on the engine at lower revs, meaning diesels can be more reliable and can last longer.

unkel

E92 wrote:

This one, Unkel http://www.bmw.co.uk/bmwuk/about/news/0,5126,1156___co-181209342,00.html tells us about the 118i, which as I said before, is soon to be launched i.e the 1 (to pardon the pun) they'll sell you at the moment does the figures JHMEG mentioned.
and this one http://www.bmw.co.uk/bmwuk/pricesandspecifications_technical_specs/0,4639,1156_149349913__bs-Mw%253D%253D%2540bb-M0xJ%2540bm-WjNTQg%253D%253D,00.html tells us about the 320d

I'd rather a link that didn't have the letters bmw in the url

Capt'n Midnight

E92 wrote:

there's no reason why petrols couldn't offer fuel economy figures close enough to diesels.

Absolutely , all they have to do is burn the petrol in a diesel engine.
...

The reason why diesels are better with heavy vehicles is because of all the torque a diesel has,

If you want more torque use a gear box.
Diesels also last longer because they have more metal in them to take the higher pressure.

http://uk.encarta.msn.com/encyclopedia_761553622/Internal-Combustion_Engine.html

The efficiencies of good modern Otto-cycle engines range between 20 and 25 per cent (in other words, only this percentage of the heat energy of the fuel is transformed into mechanical energy).
...
The efficiency of the diesel engine, which is in general governed by the same factors that control the efficiency of Otto-cycle engines, is inherently greater than that of any Otto-cycle engine and in actual engines today is slightly over 40 per cent.

25% vs. 40%
That means petrol engines would have to extract 60% more energy from the fuel than they do at present. And even then you still don't make up for the losses in the refinery in re-forming other hydrocarbons to petrol.