BS: Petrol vs. Diesel cars?

Subject: RE: BS: Petrol vs. Diesel cars?
From: the lemonade lady
Date: 29 Nov 04 - 06:22 PM

Ahem Schantieman "Haven't done enough long runs (100M+) to know what its consumption will be under those conditions." It's about time you drove it to Bishop's Castle... you'd be able to do a calculation then.

Signed,

Your Lover
8)

Subject: RE: BS: Petrol vs. Diesel cars?
From: NH Dave
Date: 29 Nov 04 - 04:39 PM

I had a man fuel up at my station last night, and I posed the question to him.

Turns out he is a mechanic at a local dealership that sells gasoline fueled cars, but drives a diesel truck to haul his boat and trailer around.

His thoughts were that diesel engines in today's cars are more robust and require little maintance other than changing the oil on a regular basis, while gasoline powered cars require frequent preventative maintenance; plugs, points in non electronic ignition (electricity is switched by an electronic system rather than points) systems, timing checks, distributor maintenance, because diesel cars don't use any of these systems - the fuel is ignited by the fuel air mixture being compressed to the ignition point of the fuel. Aside from the injectors, it is a much simpler system, and since many newer cars now include fuel injection, the diesel is much simpler in operation, with less to go wrong.

Dave

Subject: RE: BS: Petrol vs. Diesel cars?
From: Boab
Date: 27 Nov 04 - 06:23 PM

There is a seasonal bus service on Vancouver Island plying between Victoria and Tofino --a trip of over four hours one way---which runs on "bio-diesel'. [ Fuel manufactured from animal fats, used cooking oils, etc.,] A local filling station here took on the franchise for the fuel, and gets the benefit not only of the fuel sales, but also much "fallout" benefit from business to his shop and cafe.

Subject: RE: BS: Petrol vs. Diesel cars?
From: John Routledge
Date: 27 Nov 04 - 05:52 PM

The characteristics of diesel engines means that they have more pull at low engine revs and can take higher gearing. My 6 speed diesel does 57 mpg EASILY. At 70mph it does 2000 rpm. Is higher gearing the way forward.

Subject: RE: BS: Petrol vs. Diesel cars?
From: dianavan
Date: 27 Nov 04 - 04:21 PM

In Vancouver, the cars from city hall are hybrids. The taxi's are also converting. I'm not sure if they are Toyota Prius hybrid or the Ford hybrid but it seems to be the wave of the future. I asked a taxi driver if he liked it and he said they were great.

d

Subject: RE: BS: Petrol vs. Diesel cars?
From: Rt Revd Sir jOhn from Hull
Date: 27 Nov 04 - 10:18 AM

Good point Giok, but its still a lot cheaper then diesel, currently 84p a litre at my local garage.
LPG also burns cleaner, so is better for the car, and the enviroment.

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 27 Nov 04 - 05:28 AM

J9ohn LPG is good but the price of gas is creeping up, and locally it has gone from 27p to 33p in quite a short time. The conversion grant is only payable on a vehicle less tha 5 [?] years old, and I just can't see any government giving away money and not having plans to recoup it, so I see the cost of gas going up on a regular basis. The grant for purchasing a hybrid car like a Prius is dependant on how much money is left in the kitty, and there may be no grant available at all if you apply too late in the year.
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: diesel
Date: 27 Nov 04 - 01:45 AM

Thanks Bassic

I did know that ! honest ! Actually I used to know a lot more about engines than I should admit - I've been out of that trade some years and thought I still had a passing knowledge at this stage.

Since Ed posted the question - I've been reading up on variable geometry turbochargers, Variable engine compression ratios, filter and emission controls

Ouch - I've been away tooooo long !

Gotta get the books out and update them.....

Diesel

Subject: RE: BS: Petrol vs. Diesel cars?
From: Bassic
Date: 27 Nov 04 - 01:03 AM

A small point Diesel. It is Citroen and Peugeot models that have traditionally shared the same family of engines in both Petrol and Diesel aplications. Citroen and Peugeot are both part of the same Group of companies (PSA). However some specific engines do get used in cometitors cars as a result of "one off" colaberations to share developement costs.......eg Ford Galaxy/VW Sharan uses VW Diesels in both models. The "old" Rover 200/400 used the PSA groups XUD diesel engine, and small VOLVO models have used Renault based engines for a number of years. PSA and Ford have just released a jointly developed Diesel engine in yet another "developement cost saving" joint venture between traditional rivals.

With regard to overal Diesel vs Petrol performance figures, if performance per gallon is the measure.......i.e., how much "Bang" for your "Buck`s" worth of fuel, Diesel wins hands down. As this test clearly shows. Not only is the Diesel versions fuel economy superior, but so it its performance and "drivability". And that from two newly developed engines from the same maker. Yes , the Diesel model is more expensive to buy, but spending the extra on a more expensive and larger capacity Petrol verson to bring the purchace cost and on road performance figues in line would only heighten the Diesel`s fuel economy advantage still further.

To the best of my knowlege, the US and Canada have such a limited experience of modern Diesel aplications in well made smaller pasenger cars, that it is unfair to expect the North American experience of Diesel Cars to have any real relevance to the UK/Europe experience on this occasion. The few attemps to establish Diesel engines in the North American market were done with badly chosen models, using relatively un-developed engines in a market place where fuel costs had much less of an impact on engine choice. High fuel prices in Europe over the last 25 years have driven investment in Diesel Engine technology at a startling rate. A good Petrol engine of 25 years ago compared with today would "feel" very similar in terms of refinement. Even the best Diesel engine of 25 years ago would "feel" positively agricultural in comparison to almost any modern Diesel aplication. Such has been the pace of Diesel development. With North American fuel prices seeming to be on an ever rising spiral now, I would urge you to start considering Diesel as a serious alternative again, I think you will be suprised at the progress in Diesel developement since the last time a serious attempt was made to introduce Diesel Cars to your market.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Rt Revd Sir jOhn from Hull
Date: 26 Nov 04 - 11:52 PM

ED-If your looking for fuel economy and enviormental issues, consider an LPG conversion, LPG is less tyhan half the price of petrol, [about 30p a litre?], and is better for the enviorment.
Humberside police converted most of their transport fleet to LPG, and up to now, they have saved over £1 Million pounds on petrol.

[put lpg and humberside police in your searcher to read about it in detail].
The goverment run an incentive scheme, wherby tey will pay towards the cost of a cars conversion to ruun on LPG, there are terms and conditions, ie it has to be done properly at an MOT registered garage, car should be less than 3 years old, and the maximum they'll pay towards it is [i think] £1000.
there might be more conditions, there is a website about the grant , what its called, how it is operated etc, I'll try to find it.

Or alternatively, buy an lpg converted ex plod car, panda cars are protons, and they are sold through BCA [British Car Auctions].
Protons take the miles well, last one i owned had covered 238,000 miles, it was 7 years old, and cost me £120 from auction.

Subject: RE: BS: Petrol vs. Diesel cars?
From: diesel
Date: 26 Nov 04 - 11:35 PM

With my moniker on Mudcat - What can I say - Diesel is definitely the option.

Old style rules of thumb - if you drive over 40,000 miles/yr then no argument - Diesel.Under 15.000 - petrol in between - then other factors come into play.

New argument : Toyota have the Carina II, now Avensis, with a lean-burn engine. Compression ratios equaling that of Diesel - which return 50+ mpg, around towns as well as open road.

Modern Diesels : Citroen (and by that Renault/Peugeot as they use the same engines) did have a great 1.9 TD. Posts 500 miles to the tank every time (I drive a 1.9TD Xantia with 100,000 miles on it.)
Volkswagon also have a 1.9TDi with I believe simmilar characteristics.
Citroen's HDi series engines form what I hear are pushing that figure higher - They have recently produced a 1.4l HDi Turbo with figures I believe of 70mpg - that's my next car in 2 years time.

In Ireland - Diesel tends to be less expensive also.So mixed with higher mpg than 'most' petrols - runs at far greater cost efficiencies.

Environmental question. Diesel do not produce more NOx (nitrous Oxides) which are the more damageing of pollutants - Petrols do. Pertrols especially at startup and revving modes do. True the catylitic convertor does reduce nearly all these - but only when hot. Your long journey is OK for that.
Diesel is also produced by less distilling than Petrol, so technically less harmful to environment.
Petrol is definitely quieter - where do drive ? Motorways - than no -issue for Diesel, but you will find noise is not a problem in any diesel under 10 years. (the golf above is actually typical of the era)
Particulates from diesel - again no issues with modern engines, are from unburnt fuels - blocked filters, poor injectors etc. and in fact do less environmental harm.

Service issues - small diesel cars ie Peugeot 205 1.9, eat up brake pads and front tyres due to heavy engine up front. Not the same for the same engine in the larger saloon.
Normal engine service parts : No spark plugs but a fuel filter ? very light trade off.
Engine life on Diesel 300,000 miles with reasonble care.
On petrol, normally less than 150,000.

OK I'm biased - but on a long journey, still I believe Diesel tops out.

Look up 1.4litre HDi info on web see what figures they claim ? ( I just did + it's good)

Enjoy the drive (But get a turbo on the diesel - then the 15-40 K difference swings in favour of Diesel

Diesel

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Bobert
Date: 26 Nov 04 - 10:09 PM

Ohter than the furnaces-on-wheel's 0-60 mph times measured with calendars rather than stopwatches, I love the furnace cars....

I drove a VW furnace pickup for several years until it go rear ended and totaled...

Bobert

Subject: RE: BS: Petrol vs. Diesel cars?
From: robomatic
Date: 26 Nov 04 - 08:38 PM

One comment of relevance to the Atlantic divide amongst us. Europeans of the day measure auto fuel efficiency in 'liters per 100 kilometers' which threw me for a loop until I learned to convert it to MPG. BUT, when some of the UK denizens among you are listing your miles per gallon, you are probably referring to miles per Imperial gallon, which is a bit larger than the US gallon, so as the saying goes, "your mileage may vary".

The efficiencies gained by the Toyota Prius are threefold:
1) The internal combustion engine is not started by the drive, rather the car computer turns it on and runs it at optimal efficiency until it is required to supplement the electrical engine as a direct drive at speed or when passing.
2) The electric motor becomes an electric generator when braking, so that some of the energy inherent in motion is recovered to the battery rather than simply heating up the brake pads. This is why the Prius and other good hybrids often get better mileage in the city than highway driving.
3) When you are stopped in traffic, the computer will simply turn off the engine so you don't burn fuel idling. This also preserves engine life.

I test drove the early Prius in Anchorage and it performed quite well, although I'd like to hear someone who's gone through a real Winter with one.

I think using a diesel as internal combustion in a hybrid would be an excellent idea.

Early returns seem to indicate that the incidence of repairs of hybrids isn't any worse than regular cars, But I've talked to mechanics who don't like the idea of getting under the hood with electric components, so you might want to check on your nearby maintenance shops to see if they will work on a hybrid. I am keen to own one to deal with my eventual midlife crisis.

I can't wait to hear from the folks who purchase a Ford hybrid.

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 26 Nov 04 - 03:43 PM

Came over Woodhead yesterday afternoon in a queue about 3 miles long, boy was I pissed off, I had just driven 400+ miles almost non-stop and was getting to the end of my tether. Still made it to Deepcar by 1400 hrs, having left Lairg in the Highlands at 0650 hrs. Picked up my new motorhome, drove it to Barmby Moor [Dangerously near Beverley], and drove home to Scotland today.
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Terry K
Date: 26 Nov 04 - 05:56 AM

that last guest was me - still cookieless

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST
Date: 26 Nov 04 - 05:44 AM

Modern diesels are superb and a far cry from the older ones.

Unfortunately, reputations persist, so people still talk about noisy, smelly diesels which lack performance - none of which is true. Someone also said that diesels should be maintained more often - simply not true. My present car has 38,000 miles on the clock and the computer tells me it won't need its second service until 5,000 miles time, the first service having been done at 24,000 miles.

As to performance, my 2.7 common rail diesel is slightly quicker all round than the 2.4 petrol, but I average 40+ mpg whereas the petrol equivalent does 31 mpg. No contest.

cheers, Terry

oh, and diesels hold their value much better too!

Subject: RE: BS: Petrol vs. Diesel cars?
From: Bo Vandenberg
Date: 25 Nov 04 - 07:41 PM

One has to be careful talking about this on both sides of the pond. In Canada our diesel fuel is very dirty, with far more sulpher and fewer performance additives. We are also not as big a Diesel market (although I think that is changing) so volkswagen is really the only fully commited diesel player in small vehicles.

Re: Ontario "Drive Clean" Program. I believe there are different levels of pollution allowed for the two types of engine. Saying an older car passed the emmission tests could just be a function of the levels set for Diesel.

Because diesel's are not a big market here some of the popular views are very warped. Diesels are dirty but our fuel that they burn is dirty. Diesels are noisy but our selection of diesel models is very small.

I bought my wife a diesel golf because she has a long drive to work. It is noisy and (I think) a little unglamorous but it has great mileage. She's really proud of the near 800km she gets to the tank.

Sigurd

Subject: RE: BS: Petrol vs. Diesel cars?
From: MARINER
Date: 25 Nov 04 - 06:54 PM

Go for the diesel, it's easier to maintain and causes a lot less hassle from a breakdown point of view than the petrol models as long as you service them regularly. I've been driving diesels since 1978, mainly Transit Campers and have never had a major breakdown. I've recently changed to a Fiat Ducato, (got a very good deal.)and find it very easy to drive and economical. There is a company not far from where I live who are installing waste cooking oil conversions which are very easy on fuel but thre is the drawback, as someone said earlier, of smelling like a chip shop.

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Art Thieme
Date: 25 Nov 04 - 01:55 PM

substitute DETROL --- and you'll never run out of petrol. **SMILE**

(Only a special few will get the joke.)

Art Thieme

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Beerdrinker
Date: 25 Nov 04 - 08:43 AM

The advantage of the Sparrowpit route is you could stop for a pint of Robbies at the Anchor or the Wanted. Oh, and it's a nicer route.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Ed.
Date: 24 Nov 04 - 05:07 PM

Many thanks for all the detailed thoughts, and well considered posts.

I'm certainly leaning toward the diesel direction, and will be investigating the financial implications of trading my current car in the near future.

Thanks again for the intelligence and expertise of (most of) the posts.

Ed

To answer Dave's question regarding travel from Sheffield to Manchester: "Do you do Woodhead or the Snake or Sparrowpit?"

I've tried them all, Woodhead is too far north, so I either use the Snake or (more often) take the A6187 through Hathersage, Hope and Castleton, up through Winnats Pass, and then drop down onto the A6.

Sparrowpit takes longer, but is my 'bad weather emergency' route (used last during the snow on Thursday night and Friday morning)

Subject: RE: BS: Petrol vs. Diesel cars?
From: Folkiedave
Date: 24 Nov 04 - 03:24 PM

I have a Toyota Corolla diesel and it is extremely economical on fuel.

IMHO the great advantage of diesels is the fact that run properly they will easily last for "ever"...probably longer than the metal of the bodywork!!

Best regards,

Dave Eyre

Subject: RE: BS: Petrol vs. Diesel cars?
From: Don Firth
Date: 24 Nov 04 - 02:47 PM

This isn't diesel, but I have a friend with a Toyota Prius hybrid: batteries plus gasoline engine. It switches back and forth between batteries and gasoline depending on circumstances. And while sitting at a stop light, for example, everything shuts off. When the light turns green and you step on the accelerator, the electric motors kick in and away you go. These "flip-flops" (not to get political) are smooth and unnoticeable, and although you probably can't peel rubber in it, the car is fairly peppy. On the open road, he gets 50 to 60 miles per gallon. But here's the kicker: it gets even better mileage in city traffic.

He loves it. He waves and smiles (smirks) as he passes gas station after gas station.

Honda and Ford have similar offerings. And people who have them seem to really like them.

Don Firth

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 24 Nov 04 - 02:29 PM

You should be able to get 200,000 miles out of a well maaintained diesel.
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: jonm
Date: 24 Nov 04 - 12:30 PM

I have recently converted from the 1.6 petrol model to 1.9 turbodiesel of the same model of car.

The petrol model returned 32mpg average (22 mile commutes, lots of long distances, some town running), or 11.9 pence per mile using the rate at my local station.

The diesel gives me 42mpg on the same driving pattern, which equates to 9.2 pence per mile, since diesel is more expensive.

Modern diesel engines emit fewer hydrocarbons and sulphates than petrol and I waited to get a diesel engine with both a particulate filter and a service interval the same as a petrol car (previously, the diesel model was 9000 miles to the petrol's 12000).

Diesel models of my car cost approximately £1000 more than the equivalent petrol model at one year old (the age when I normally buy my cars). It will therefore take me 37000 miles to recoup the extra outlay.

That's 18 months' motoring for me and diesel engines tend to wear higher mileages better. The increase in torque and low-rev power also swung it for me.

Hope this helps.

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 24 Nov 04 - 12:30 PM

Heavy plastic?
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Chief Chaos
Date: 24 Nov 04 - 12:22 PM

Warning thread creep!

Doesn't it alarm you guys that the average efficiency of a car has gone down, not up over the years?

I used to drive a '68 Mustang with a V-8 (289 cubic inch) engine. On the highway it got the same mileage as my brothers 1984 Trans Am which was far more aero-dynamic and mostly plastic.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Dave Bryant
Date: 24 Nov 04 - 12:01 PM

Both Linda and I drive Diesels, she a Vauxhall Astra 1.7 TDI, and I a Peugeot 405 1.9 TDI. Both cars give excellent fuel consumption figures even pulling the caravan. In some ways, I would tend to say the reverse of Bassic, as we find that the diesels seem to love purring along on long motorway jouneys. Because a diesel engine relies completely on the heat of cylinder compression to provide ignition of the mixture, it tends to run more efficiently after warm-up. Thats why the MOT emissions test on a diesel have to be made after the engine has reached a certain temperature.

Because no electric ignition (spark plugs etc) are used on a diesel engine, wet and damp conditions make no difference to starting or running (you won't need to spray with WD40). Cold weather can however be a bit more of a problem. The high compression ratio of a diesel engine (more than twice that of a similiar petrol engine) does mean that you need a good battery to warm up the heater plugs and then crank the engine.

Incidently, the sugestion about running on agricultural diesel could end you up with a big fine. There is an additive in it which produces quite a distinctive smell, and quite small concentrations can be detected if the contents of your tank are tested, so it will show up for a long while. From a spell of work at London Airport, I know that jet aircraft fuel works fine and is not as obviously detectable - of course I've wouldn't dream of breaking the law like that though.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Schantieman
Date: 24 Nov 04 - 11:22 AM

..er.. American-speaking people, actually, but let's not go into that.

In September I bought a nearly-new (March 04) Vauxhall Astra 1.7 DTI to replace my 1991 petrol VW Golf 'Driver' 1.8 (which had done 178 000 miles).

It's already proving to be more economical - I'm on my third or fourth tank of diesel and have been averaging 50 mpg so far compared to about 40 in the Golf which is smaller and lighter. I don't drive to work (about a mile) unless I'm going on somewhere else afterwards, so it doesn't do many short journeys. Haven't done enough long runs (100M+) to know what its consumption will be under those conditions. Anyway, I've been tending to drive it too fast just for the hell of feeling the turbo kick in. When I grow out of that It'll probably do better.

It's not so much the car, but how one drives it (ahem) and the journeys one asks it to do. I think we should all use public transport as much as poss & reduce the number of cars on the road. Then the buses would be able to go faster.

(dismounts from hobby horse)

Right - off to drive 15M to Southport, the shortest journey I regularly drive, about twice a week. O;-)


Steve

Subject: RE: BS: Petrol vs. Diesel cars?
From: Once Famous
Date: 23 Nov 04 - 04:05 PM

Guest, Sam Hall

I am very well aware that not everyone here is American and that in Britain, England, UK, or whatever you guys are, we can fit you easily into the state of Texas.

So it's called gas by consderably more English speaking people than it is called petrol.

Anyway, I would consider eating some boiled potatoes and then farting in the gas tank as it would be much more economical than buying a VW diesel.

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Charmion at work
Date: 23 Nov 04 - 03:58 PM

I have been driving diesel Volkswagens since 1983, and I'll never go back to petrol -- I love that feeling of passing filling stations. Here in Ottawa, the in-city mileage (kilometrage!) is not that much better than with a gas-fired car, but on the highway the difference is startling; we can go to Toronto and back on 50 litres, and drive around for several days after. My first diesel car, a Rabbit, was a pain in the neck, but the 1986 Golf that succeeded it is still running sweetly -- I sold it last year to a guy who was trading up from a 1982 diesel Rabbit that his wife refused to ride in any more. We are now driving a 2003 diesel Jetta station wagon.

Ontario has a "Drive Clean" program that tests the tail-pipe output of cars over three years old for particulates and various noxious gases. The Golf was tested before sale, and passed with flying colours without even a pre-test tune-up. The Jetta is a turbo-diesel that performs at least as well as any gas-fired car on the road (short of a Mercedes, of course), and better than most. The closest contender in our pre-purchase test drives was a Volvo that cost half again as much, and flunked my taste test because of comparatively mushy handling and poor cornering.

Ontario is notoriously hard on cars -- after seven years most of them act as if they don't owe you anything, shedding body parts and generally crapping out. Despite the salt on the roads and the miserable witners, elderly VW diesels are to be found in every parking lot in town. If you can keep the body together, the engine will just keep going, and going, and going ...

The City of Ottawa has bought a fleet of diesel Golfs for its by-law enforcement officers, inspectors and property-standards people. They look efficient, comfortable and cute.

Charmion

Subject: RE: BS: Petrol vs. Diesel cars?
From: Dave the Gnome
Date: 23 Nov 04 - 03:31 PM

Sounds good indeed. I can't wait for the cheap portable hydrogen extracor though so we can run our cars on water. What will the Oil Shieks do then, eh?

Errr, excuse me please, can we buy some water?;-)

Cheers

DtG

Subject: RE: BS: Petrol vs. Diesel cars?
From: CarolC
Date: 23 Nov 04 - 02:39 PM

Here's some interesting information about the VW diesel hybrid:

Motoring.telegraph

It'll probably be more expensive than the non-hybrid equivalent (at least until economy of scale allows the pricing to become more competitive), but think of the savings in fuel costs over the life of the vehicle. And they're making it so that it can run on biodiesel. No more dependence on a dwindling petroleum supply and foreign oil sources. Sounds promising.

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 23 Nov 04 - 01:19 PM

Hope it's not as overpriced as the Golf!
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: CarolC
Date: 23 Nov 04 - 12:47 PM

I heard that Volkeswagen is coming out with a hybrid diesel. That seems like it is the best of all possible (currently or soon-to-be available) options in terms of fuel efficiency as well as low pollution levels.

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Chief Chaos
Date: 23 Nov 04 - 12:34 PM

And for those of you who are put off by the lack of performance, you can install a cylinder of propane injected into the cylinders which gives you a huge performance boost.

Not good for the environment!

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 23 Nov 04 - 11:49 AM

And vegetable oil at 50p a litre from Tesco.
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: Rt Revd Sir jOhn from Hull
Date: 23 Nov 04 - 11:10 AM

Another advantage of diesel cars, is you can run them on red diesel from your local freindly farmer.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Paco Rabanne
Date: 23 Nov 04 - 11:03 AM

Bloody hell Bassic, that was a huge post! Like Giok, I had a diesel berlingo which did 48 miles to the gallon. I currently have a fiat scudo which returns the same mpg. The BIG advantage of diesel over petrol is that the engine will last twice as long as a petrol, be a bloody sight more reliable, and cold starts are a doddle with glowplugs.

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 23 Nov 04 - 10:40 AM

Back in my peugeot 205 days I also had an American motor home with a 7.5 litre petrol engine, so it wasn't too economical. When we sold our house in England and moved to God's Country [Scotland] she followed while I drove the big beast at no more than 55 mph to save fuel, and she returned 66 mpg in the 205.
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: Bassic
Date: 23 Nov 04 - 06:41 AM

Petrol.

Modern engines are (relatively) clean in terms of their emissions.
Short stop start journeys are where Petrol is less efficient. They use much more fuel under these conditions and the Catalytic converter (which is what cleans up petrol car exhausts) takes several minutes to warm up to efficient opperating temeprature. So, from an environmental and economy point of view. A petrol engined car is at its best on longer journeys. Regular servicing of Petrol Cars is critical to maintining their economy and enviromental standards.

Diesel.

Modern Turbo charged and intercooled diesel engines with electronic engine management systems are (reletively) clean. Particulates have been reduced dramaticaly and with modern Low Sulphur fuels which are now the norm in the UK, even further to a point where they are largely insignificant compared with other sources of particulate emissions in the environment. These engines are quick to to achieve their maximum efficiency and have their biggest advantage over Petrol Cars in town and city stop go driving. (Look at how many Taxi`s are diesel powered!.)
This is because of the Power characteristics of Diesel engines which produce more useful power at lower "revs" so the engines have to be driven less "hard" in city conditions to keep up with trafic. In open road and long distance driving a Diesel looses SOME of its economy advantage over Petrol but still should return between 10 and 20% better figures than a Petrol equivalent. Yes, there are small Petrol Cars which, if driven very gently, will give 40-50 MPG on a run. But speak to drivers or small Diesels and their TYPICAL fuel consumption will be between 45 and 50+ MPG no matter how and where they drive, town, Motorway, mixed......it makes very little difference. I had these figures from an "old generation" Peugeot 205 Diesel in the mid 1980`s (all carefully documented) and so I am not exagerating here at all. I must confess however that I did once manage to get the consumption down to 38 mpg.............towing a Caravan at 60 on the motorway!! :-) A modern equivalent of that car should easily be giving 50+ mpg and probably much better performance as well and a GREAT deal more cleanly.
Service intervals on Diesels are now simmilar to most Petrol vehicles and the service is a much simpler affair.........usually just oil and filter changes as with Petrol cars........but no ignition system and spark plugs to be replaced or need adjustment of course! (Another factor which improves Diesels "whole life" economy and environmetal credentials vs petrol.)

I am consious that my opinions only relate to UK driving conditions, model availability and costs. But for me it would be Diesel every time unless there were some specific need that would preclude it. For example, needing an Automatic Gearbox in a small car.....they just dont sell em in the UK with a diesel engine! or a very low annual milage.

In my view.........for the type of driving that you do Ed, a modern Diesel made in the last 5 years, would suit you very well. You do enough miles for the economy adavantage to be significant and would be making less contribution to global warming as a result. I think you would also enjoy the driving experience of Diesel cars these days. Petrol vehicles, in order to get those economy figures and environmental benefits, have become gutless and harder work to drive in normal conditions.....unless you put your foot down, and then of course you loose those benefits big style!! Hope you find something to meet your needs........come back and tell us which way you have decided.

Subject: RE: BS: Petrol vs. Diesel cars?
From: JohnInKansas
Date: 23 Nov 04 - 04:19 AM

Ed -

The performance and total cost of operation for newer diesels vs newer petrol/gasoline engines is probably close enough that you can make the decision based on "personal feeling" - or ignore the difference for most kinds of driving.

The "polution differences" cited in the link you gave may be a little dated, since they claim lower lead emissions. In the US, and I assume in the UK, lead additives were eliminated from gasoline several years ago, so that difference went away. Diesels do have a tendency to put out higher NOx (nitrous oxides) and particulates, and commonly available diesel fuel is often higher in sulphur, so you expect a little more SOx emissions. The particulates are probably the biggest complaint, since that's what makes diesels "smell bad." Under high engine loading (full throttle) and commonly under almost any rapidly changing loads, the fuel is incompletely burned and just spits out the exhaust stack like an oil spill (in aerosol form, of course). The NOx emissions are probably the most environmentally damaging, but that sort of depends on who you ask.

With either type, a properly maintained and properly driven engine of either kind need not be a major "polluter." Diesel engines do tend to "burp" their emissions during load changes and at full throttle. They are best suited to situations where they can run for long stretches at constant speed and fairly constant load. For long-haul trucking, the diesel is unquestionably superior, but they really do need those 15-speed+ transmissions to keep the engine loading within optimum ranges. For "downtown deliveries" most heavy haulers are about as likely to use gasoline engined vehicles because of the characteristically better performance in "stop-and-go" driving. If your commute is less than 80 or 90% "constant speed highway" driving, you'll likely do better with a gasoline engine. Even if it's all on a freeway, if the traffic causes constant speed adjustments a diesel engine will be "less friendly" than a gasoline one.

Although new "lightweight" diesels are out there, the whole package of engine and drivetrain is nearly always significantly heavier in a diesel vehicle, hence the common use only in vehicles large enough so that difference doesn't matter much. A smaller gasoline car, if it suits your usage, could offset most of the "fuel economy" advantage of the typically heavier auto diesel.

In my area, diesels are available in a wide variety of more-or-less suitable vehicles, but about the only ones who use them for commutes of less than 100 miles per trip (1,000 miles per week commute) except for towing and for vehicles over about 8,000 lb (3,600 kg?) are those for whom the "macho effect" is the main consideration. Especially if you're stuck with older vehicles, gasoline is still preferred by most - unless there's a "diesel requirement" such as a need for towing ability or a very large vehicle.

Some of the "luxury class" heavy sedan models have made quite good diesel applications, but for most commuters a properly maintained (smaller?) gasoline vehicle is likely the best choice. Given the distinctly different kinds of maintenance needed, and the different driving habits that should be learned, most people are also much more likely to operate acceptably and to do proper maintenance on a gasoline vehicle - and less likely to be an "environmental burden" that way than if they abuse a diesel.

For comparison: My town was cited for "hospitable working conditions" in a fairly recent survey because the "average commute" was only 18 miles per day (one way). The national average one-way commute in the US was reported as something around 38 miles (380 miles per week?). I can think - offhand - of at least a half dozen people among current friends who have driven 75 miles or more to work each day (750 - 900 miles per week) for several years, and we've discussed this tradeoff extensively.

Drive safely, maintain your vehicle, and don't feel guilty. There's not that much difference in principle between modern gasoline and modern diesel engines.

John

Subject: RE: BS: Petrol vs. Diesel cars?
From: Dave Masterson
Date: 23 Nov 04 - 03:27 AM

I have a Renault Clio 1.5 diesel - a round trip to work of 95 miles - mostly motorway (freeway) on which I get approx 75 mpg! And servicing intervals of 2 years or 18,000mls. I am a happy bunny.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Shanghaiceltic
Date: 22 Nov 04 - 11:43 PM

You get better mileage out of a deisal engine which must mean you are buring less fuel which might offset the anti diesal feeling that they worse for causing pollution.

I hired a Golf when I was in the UK in the summer and it did over 500 miles on a 45 litre tank.

Subject: RE: BS: Petrol vs. Diesel cars?
From: GUEST,Sam Hall
Date: 22 Nov 04 - 06:52 PM

Martin Gibson, you seem to assume that everyone on Mudcat is American. Over here it is petrol. Do try to be a bit more cosmopolitan (and no, I don't mean the women's magazine). Gas is that cloud of noxious vapour that surrounds you.

Subject: RE: BS: Petrol vs. Diesel cars?
From: CarolC
Date: 22 Nov 04 - 06:06 PM

Or you could get a diesel and burn bio-diesel fuel in it. Not sure what sort of fumes you'd get with that, but it would smell like chips (French ...freedom fries).

Subject: RE: BS: Petrol vs. Diesel cars?
From: Dave the Gnome
Date: 22 Nov 04 - 06:06 PM

Aye - True about the trian times unfortunatley, Ed. That run from Sheffield to Manchester and back is one of the most spectacular in the country! Driving can be a problem with delays though as well can't it? Do you do Woodhead or the Snake or Sparrowpit? All awful when the snows begin to fall I'm afraid:-(

Hope it doesn't affect you to much though.

D.

Subject: RE: BS: Petrol vs. Diesel cars?
From: Ed.
Date: 22 Nov 04 - 06:02 PM

Thanks, Dave

I'd love to do the train, but it's entirely unreliable, and my company stresses turning up on time as being very important. As such, I have little alternavive...

Subject: RE: BS: Petrol vs. Diesel cars?
From: John MacKenzie
Date: 22 Nov 04 - 05:48 PM

Small modern diesels are very efficient, although some of the newer petrol engines are very economical too. I always buy diesel as they are less complex, and easier to service yourself if you want to. Just ask yourself why there are so few commercial use petrol engined vehicles, diesel makes sense. I run a Citroen Berlingo 2litre HDi, and it's a great little car.
Giok

Subject: RE: BS: Petrol vs. Diesel cars?
From: Dave the Gnome
Date: 22 Nov 04 - 05:43 PM

Your 1.4 VW Polo is fine, Ed. The hydrocarbon emmisions are no worse than any diesel plus you are not putting out any heavy pollutants, which diesels lean towards, that, although not environmentaly damaging, can kick off some allergic reactions.

The other thing is that your petrol engine willl not use as much oil as a modern diesel, nor will it need maintaining as often, making it more environmentaly friendly in other ways.

Hope this helps. I thought you were doing the train though?

Cheers

Dave