Diesel Vs Petrol

gazfast

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G'day, anyone out there like to debate the pros and cons of high speed diesel motors vs petrol engines in passenger cars.

I am declaring myself to be a big fan of the high speed diesel, having driven plenty and owned a couple, BUT, that is not too say I do not believe the petrol engine is dead either, particularly withthe chance to run alternate fuels such as ethanol or LNG/LPG/CNG.

Well, over to you fine people, please, kepp it clean, nothing nasty, I am interested in hearing what people have to say on the topic, for or against...
 

jimishtar

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its hard to compare them. diesel engines have more torque n rpm, while also consume less fuel, so are more suited for heavy vehicles and off-road driving. the downside is that they have less horse power and they have that oily smell.
petrol, on the other side, delivers more horse power, so its widely used as a performance fuel in racing, and its the most common, let say, public fuel. downside is that they consume a lot of fuel, and have far less torque n rpm. most petrol engines struggle when faced with heavy loads or off-road tracks.

i personally prefer diesel engines, since their development have brought them so close to petrol engines. I don't see the point of driving on petrol when u get the same performance for less money with a diesel.
 

szymek

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I'm taking petrol enginge. But it's only because I like more power on high rpms. If you want to have a car which youll be driving in city, then diesel is a better option for you. And it's not true that diesel is cheaper, since you have to pay more for such engine.
 

pastit

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It depends on the way you drive.
If you want out and out performance then you have to have petrol; LPG, diesel or other fuels (Excluding exotics) do not provide the energy. It does come as a cost though.
For normal driving diesel is just as good, and is better if you need to tow.
JB
 
G

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Diesel during the week (mazda 6 ts2 2.0 tdi) petrol on the weekends (EVO VIII fq300 360 bhp)

Diesel engines are just more efficient and cost far less to run and modern ones are quiet and dont smell anymore!
 

gazfast

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All essetially the reason we bought the Pug, it is a great town car, I am lucky to have access to some fun toys for weekend work, still tingle at the thought of the AMG E-Class, 245km/h before acking off to avoid getting airborne...thrilling.

However, we have a 12 Hour race here every Febrary at Mt Panorama, aka Bathurst, and I am hot on the idea of racing a VW Polo or Golf diesel, not as much outright power, I admit, but plenty of torque for in-gear acceleration, they will certainly climb the mountain no sweat, and actually, produce pretty scary power levels once you start to tune them...decisions, decisions...
 

jimishtar

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usually turbo diesel is same like a petrol in performance. it is true that diesel car costs more than the petrol version, but by spending less money on fuel, the investment pays for itself. unless you drive your car 2 times a week, in that case go for petrol. :)
 

Walkfire

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I have owned at least 13 autos, including a Mustang, a Gimmy, a Camero and a Town & Country, a MGB and a Carmengia and a bunch more. Some of them were new, most were used and required all kinds of work which I usually did myself. I love fast and efficient and of all my cars the very best on fuel effeciency and flat out speed is my TDI Jetta 2002.
The Turbo Deisel is kick ass and I can take most stock cars off the line and up the Mountains. I easily can cross 110mph accidently while passing and in regular driving I get 51 mpg. Thats right. 20 mpg better than most of our best milage gass autos get. Consider how many gallons you burn per year and then multiply that by at least 20.
Before Catrina when Desiel was priced fair it cost a third of what Gasoline cost. Now it cost more but still there is no comparison to what I save and get to appreciate in my little speedster.
 

ulysses35

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I recently made the change from Petrol to Diesel.... and wont be going back. Sure petrol engines have better throttle response and hence a slight advantge in pulling away from standstill - however the advantge is very small. In my case the turbo diesel in my current car is quicker on the move due to the torque advantages and the light pressure turbo makes up for any performance loss over the old petrol.

Better still - used cars (year old diesels) are just as cheap as petrol - but have better fuel economy
 

jamesgoddard

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Diesel is just downright safer - ask any military unit around the world what fuel they use - it's not because of efficiency, but when there are bullets flying around you don't want to be sitting on a potential fireball. Diesel fuel very rarely ends up catching fire or exploding.

Petrol (gasoline) as we know will catch very easily and IMHO it's not worth even the small risk, especially with my kids in the car. And don't get me started on either LPG or worse, cars with 1/4 ton of lithium under the seats, both of these are mobile mini nukes... Can't be long before we hear a story of a lithium car battery going gaga (like some laptops have done) just with 1000x the amount of explosive lithium!
 

amnotanoobie

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Diesel.

Modern CRDi engines doesn't have the noise or smell of old diesel engines. And I agree with jamesgoddard's point, diesel needs compression and/or heating up before it burns, unlike petrol which burns instanteneously.

Although most supercars are petrol, that is why the R8 holds a special place in my heart :p.

* Of course, there's the other issues of diesel such as it needs 25% more crude to make and it spews out more particulates than petrol when burned. But I don't mind as diesel cars and fuel is cheaper from where I'm from.
 

howardp6

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The thermal efficiency of the diesel engine is higher that a petrol (gasoline) engine due to its higher compression ratio. After all both are just heat engines are governed by the laws of thermal dynamics. It is about 30 to 40 percent more efficent. You have to weight the fuel costs, versus the difference in price. Diesel engines are heavier, a little noisier and harder to start and usually are more costly. The torque at engine speeds is different. The availiablity of the fuel is another factor. It is usually a matter of personal perference.
 

Nick_C

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Unfortunately the R8 V12 TDi has been canned - too many problems shoehorning the V12 motor into the engine bay and keeping it cool enough.

I went diesel when I last changed cars. I do in excess of 18,000 miles per year and average about 44mpg. I would not buy another petrol car unless my annual mileage drops significantly.
 

gazfast

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True Ford might not make a GT500 diesel, but there are some deadset rockets, try VW Touareg R50, 5-litre V10, two turbos, even in a 4WD wagon it will blow a WRX away (Did it myself), and still offer reasonable fuel consumption, plus a full factory warranty.

the point to consider here is that engineers have been working on petrol motors to make them more powerful and more economical for decades.
That research is only just starting on diesels, especially the small capacity 'high speed' diesels, which means in about 10 years time, there will be some genuine purebred race-type diesels on the road...Peugeot uses the same HDi and FAP technology in my road car that is used in its Le Mans winner, except mine is 2.0 litre and the racer is 5.5 litres.
 

gazfast

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howardp6

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Crashman

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Engineers argue that Turbos recapture waste energy from the hot exhaust gases. Recapture waste, as in more efficiency. As in, a 2.0L turbo making the same power as a 3.0L non-turbo but with lower fuel consumption.

Superchargers take power from the crank, they don't reduce waste energy at all, so efficiency goes down.
 
Audi just started advertising the A3 TDI in the States. That might just might end up being my next car...but until then I will continue to enjoy the 40+mpg of my Jetta TDI!

JETTA TDI FTW!!!!!!!!!!!!!!!! :pt1cable: :eek:

America could be on the leading edge of bio-diesel vehicles and bio-diesel technology, especially with the state of the American auto industry and the willingness of Obama to spend my tax dollars to fund alternative fuels and alternative fuel vehicles. Unfortunately diesel technology, and even clean diesel, suffers from a perception issue as many Americans only remember the smelly and noisy diesel cars from the early 1970's as well as the countless 18 wheelers up and down the highways. However, what most Americans and the auto industry fail to realize is that if you truly want a vehicle that will consistently get over 40mpg and still maintain the performance of a V6 or small V8 petrol engine, a 4 cylinder turbo diesel is all you need. And, if the auto industry wanted to sell and the American car buyer wanted a high mileage, fuel efficient vehicle, that is also environmentally friendly, a diesel-electric hybrid vehicle is exactly what they are looking for. Sad to say that, in America, diesel suffers from a total lack of political will, financial backing, and the testicular fortitude required to have clean diesel technology in the forefront of the American auto industry and car buyer.

Yes Americans, you could have your high HP and high MPG cake and eat it too...just start demanding clean diesel cars and light trucks as well as diesel-electric hybrid vehicles!
 

Walkfire

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Symbolically Speaking, "Pride's" closest relative is "I Believe" and together they have pissed on more ingenuity and science then any of our other attitudes.

I get the sense that you are just kidding, yet just kidding often is the tip of the ice berg exposing just a hint of a massive belief.
Perhaps not even a belief your committed to personally, but in your sense of humor you have brought the elephant into the room.

The USA is embarrassingly undeveloped in green technology due to such apathy and self gratifying opinions.
Truly Mrface, it is not you I am speaking to, it is the idea you have teasingly rolled across the table and I responsibly must respond to this elephant.
 
lol, wow...

Sure you are free to comment how you want...

Ill keep my gas car for now as I am happy with it, and no it isnt apathy that drives me. I truly love the car. :p

show me a diesel for the money that gets that power?

some people make sacrifices, albiet for the earth or for the power, its your choice.

[/btw it was sarcasm and you responded correctly. just a litte funny to me thats all]
 

Crashman

Polypheme
Former Staff


I'll keep mine because recycling a fuel-thirsty car to make a less fuel-thirsty car takes more energy than than you could save by driving the more efficient car for ten years!

In other words, its "greener" to extend the life of a "gas guzzler" by ten years than it is to replace it. That's something the politicians and touchy-feely left-coasters won't tell you.