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View Poll Results: petrol or diesel for performance ?(read post before vote)
Petrol 129 69.35%
Diesel 57 30.65%
Voters: 186. You may not vote on this poll

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Old 21st March 2010, 09:10   #16
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The TSi for sure. The A4 TSI and TDI ( 2.0 ) are priced similarly. And the TSi blows the TDI cleanly out of the water. Forced induction of a high revving Petrol engine is one of the sweetest things to ever to cars.
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Old 21st March 2010, 09:18   #17
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I'd say Petrol.
With a diesel 1st gear , 2nd gear you have to floor the accelerator and wait for the RPM increase until the turbo kicks in. Whereas with petrol its almost instant.
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Old 21st March 2010, 09:54   #18
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Petrol has to be it.
Due to high Rev nature of petrol engine and continuous surge of power where as diesels loose power after their specified max rpm's.
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Old 21st March 2010, 10:09   #19
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With due respect, I find this discussion flawed

1. The definition of performance in itself is undefined. Torque, FE, HP, Power per litre are all measurements of performance.

a. Torque: Diesel engines usually have a higher torque (thanks to the higher compression ratios) and hence are preferred for commercial applications in trucks and trains.
b. Fuel efficiency / Horsepower / Power per litre: The most significant technological breakthroughs concern the development of direct injection and common rail turbodiesel technology. Direct injection, as the name suggests, is a process by which the fuel is injected directly into the combustion chamber. The fuel supply can therefore be controlled more precisely, improving the efficiency of the combustion process. The latest common rail systems can also operate at a much higher pressure, further enhancing the
detonation process. The result is more performance with improved fuel efficiency.

2. Drawing conclusions by comparing a 3 litre petrol engine with a similarly sized diesel engine is not correct. The same engine can be tuned for different levels of performance. 1.3 MJD a.k.a "National Diesel Engine" and the 1.5 Honda iDSI engine have all been applied in different power avatars across different models.

3. Some commentators have suggested that we’re entering the age of the diesel, but such proclamations might be premature. Much of the technology that’s being used to such fine effect in modern turbodiesels is also beginning to filter into petrol engines. The Volkswagen group, for example, already offers a range of direct injection petrol engines that offer improved fuel economy and lower exhaust emissions

4. The only reasons why petrol engines were preferred for racing all these years was
a. It had a higher rev band than a diesel engine
b. It was a much lighter engine and can be matched to multistage turbo more easily
c. Many sports car drivers also continued to prefer the sonorous roar of a performance petrol engine to the more muted, deep bass mutterings of a diesel.
d. While Le Mans may be populated by diesels, sprint racing will continue to be dominated by petrol power. A diesel-powered F1 car remained and remains a preposterous
suggestion

Last edited by acidkill : 21st March 2010 at 10:12.
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Old 21st March 2010, 10:36   #20
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Quote:
Originally Posted by pgsagar View Post
I disagree with the second part. Sure, diesels make torque much lower down the rev range and hence will be first off the mark. But petrol will eventually catch up when the dizzying revvs finally build up and wave of torque piled up at higher rpm pushes the car with a rush. Yes, petrol needs a long straight to catch up with diesels. But once it does it will just blast past diesels which although take off very fast but pretty quickly they run out of the steam towards higher rpm range when the torque tapers off. Since we do not have that kinda straights in India, we feel that diesels are winner. Give us a straight like they have in Australian outback ( 160 km of arrow straight uninhabited road ) and see who wins.
No. That is incorrect. For same powered engine, any engine that generates torque at lower RPM band will always hold the edge. In this case, it happens to be a diesel. One main reason why Balenos of yesteryear were almost as quick as higher powered other cars was that they produced peak torque at much lower RPM.

I do not have data handy, but I'll not be surprised if 120 BHP Optra Magnum is quicker than 118 BHP Honda City (assuming both weigh the same). Or, if 110BHP Verna has almost same 0-100, 0-160 numbers as 118 BHP Honda City.

Whatever you said, will hold good, if the Petrol engine eventually produces more power than Diesel at those high RPMs.

P.S.: And most probably, an electric car will kill both Diesel and Petrol, since it has peak torque starting from 0 rpm.

Last edited by RX135 : 21st March 2010 at 10:45.
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Old 21st March 2010, 10:55   #21
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To compare apples to apples one needs to pip A turbo petrol like SKoda to the likes of a Turbo Diesel like Cruze or Optra Magnum. But then some might liken the rush of adrenaline that comes from a high revving petrol compared to those who liken the torquey pulling power at low revs.

PS: Wondering why I have never seen a supercharged diesel!!!
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Old 21st March 2010, 11:04   #22
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Quote:
Originally Posted by raj_5004 View Post
sorry but thats wrong info. agree about the skoda 1.8 but not the BMW.

0-100kmph timings of-

BMW 530i - 8.71 secs
BMW 530d - 7.08 secs


BMW 320i - 11.57 secs
BMW 320d - 9.39 secs

Audi A4 3.2 FSI - 8.05 secs
Audi A4 3.0 TDI - 6.68 secs

Source: Autocar India
I'd like to disagree Raj. The BMW official website gives an entirely different timing.
BMW 530i - 6.70 secs, top speed 250kmph
BMW 530d - 6.80 secs
, top speed 248kmph

I guess Petrols still have the upper hand over Diesels.

BMW India : 5 Series Sedan : All the facts : Technical data

Last edited by Rehaan : 24th March 2010 at 12:59. Reason: Correcting as per your mention
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Old 21st March 2010, 11:08   #23
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The thrill you get when you hit the limiter in a petrol engined car is to die for
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Old 21st March 2010, 11:28   #24
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Nothing concrete would come out of a discussion comparing petrol and diesel engines in general..I have opted for petrol, reason being I have largely driven a petrol.

.My daily run is the baleno, The only diesel i have driven till now is the swift ddis for some 200kms, so based on my limited understanding the car is fast but not quick. It is the torque that makes the driver feel that the vehicle is quicker.

Carwale.com:
0-100kmph (seconds)
Swift DDis - 14
Baleno - 12.8

1/4 Mile (seconds)
Swift DDis - 19.1
Baleno - 20

I feel this would be totally different for engines running on luxury cars (i.e.) turbo charged petrol/diesel..

Last edited by Mr_Bean : 21st March 2010 at 11:33. Reason: k
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Old 21st March 2010, 13:35   #25
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Quote:
Originally Posted by BuBooMan View Post
FACT : The quickest ROAD cars in the world are petrol. Bugatti Veyron, Ferrari 458, Lambo 670, Porsche 911 Turbo etc. I respect what Audi and VAG is doing for the diesel. Especially on their road cars. I kno cos I have owned a few. If only I was a bit richer and had a stonking petrol in my garage. Hmmm.
The only reason why the quickest road cars in the world are petrols is because the majority of people stil think Diesel powered cars are slow. And Ferrari is the last company to prove otherwise.

Audi and Peugeot went into Le Mans with Diesels to prove otherwise. When Audi UK decided not to bring in the R8 V10 TDI customers forced them to do so.

With the Fiat 1.9 16v M-Jet we are currently at 265bhp and 460lb ft of torque. We are working on more. You won't be able to get this sort of torque per litre from any force induced petrol engine.
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Old 21st March 2010, 13:43   #26
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Quote:
Originally Posted by CPH View Post
The only reason why the quickest road cars in the world are petrols is because the majority of people stil think Diesel powered cars are slow. And Ferrari is the last company to prove otherwise.

Audi and Peugeot went into Le Mans with Diesels to prove otherwise. When Audi UK decided not to bring in the R8 V10 TDI customers forced them to do so.

With the Fiat 1.9 16v M-Jet we are currently at 265bhp and 460lb ft of torque. We are working on more. You won't be able to get this sort of torque per litre from any force induced petrol engine.
Both Audi and the Bugatti belong to VW.The Audi R8 has a diesel.Then why didn't the Veyron get a diesel mill?
Going by what you say, diesels are as fast or maybe even faster then petrol. Then why aren't they racing using diesel mills? Why does F1 still use petrol mills?

Last edited by rg_chn : 21st March 2010 at 13:46.
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Old 21st March 2010, 14:25   #27
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Quote:
Originally Posted by rg_chn View Post
Both Audi and the Bugatti belong to VW.The Audi R8 has a diesel.Then why didn't the Veyron get a diesel mill?
Going by what you say, diesels are as fast or maybe even faster then petrol. Then why aren't they racing using diesel mills? Why does F1 still use petrol mills?
I am not only a performance tuner. I am also an automotive consultant, but I hate this part of the job and do it less now dipite the money that can be earned.

The reason why I hate it is because common sense doesn't prevail. This means bangingyour head against the brick wall and I dson't like to bear such pain.

To start with the Veyron was purely an engineering exercise. Many things went wrong during development. Fitting a Diesel engine would have created even more problems for the engineers.

When the Veyron was pinned it was only the Audi division that worked on a strategy to market a Diesel powered super car. The marketing people are too afraid to go into new territory. The are like bankers = no vision and whimps.

The Lamborghini is lined up for Diesel engines, but some people hold back the release.

Unfortunately for the Diesel powered cars is not a good time right now to explore new markets as the push from politicians towards electric and renewable energy powered cars is getting harder.

The industries doesn't want to invest into technology that doesn't repay.

They all are sitting on the fence waiting for changes in the market. Many people think that the electric powered cars have no future either because with current technology they are the worst poluters ever because lithium ion batteries last on average only two to three years being a tremendous environmental hazard. This would mean in the long run for cars alone over 4,000,000 articulated truck loads of batteries to be disposed of.

F1 was close to collapse. The majority of people in the past years lost interest (which only changed last year) and manufacturers are pulling out for cost reasons.

Bringing in Diesel technology would incur extorsionate cost in development. Diesels outrun petrols in long distance racing and in most (so called) saloon racing classes. Diesel engines are made to last, which is not something F1 is about. In F1 the engine designers need power. Creating the power is fairly easy. But this power must be maintained for a certain time. Nobody has got any experience to make a Diesel engine extremely powerful, but light.

In any case it would only be possible to have a Diesel in F1 if forced induction was permitted, which might come in within the next few years. One idea was to introduce supercharged 2.2 six cylinder engines that are restricted to 10,000rpm.
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Old 21st March 2010, 15:21   #28
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Well, define performance first. If it is top speed it is Petrol, but for maximum load pulling it is diesel.
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Old 21st March 2010, 15:39   #29
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Quote:
Originally Posted by raj_5004 View Post
sorry but thats wrong info. agree about the skoda 1.8 but not the BMW.

0-100kmph timings of-

BMW 530i - 8.71 secs
BMW 530d - 7.08 secs

BMW 320i - 11.57 secs
BMW 320d - 9.39 secs

Audi A4 3.2 FSI - 8.05 secs
Audi A4 3.0 TDI - 6.68 secs

Source: Autocar India
You bring in-gear acceleration and things will tilt even more towards diesel.
Diesels pack more power per drop of fuel. Problem was only in extracting the power in a rapid manner, which is no more a problem with modern technology.
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Old 21st March 2010, 19:16   #30
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Comparing turbocharged diesels with naturally aspirated petrols is not right. All the diesels that we get here are turbocharged and in the naturally aspirated form, they can't hold a candle to the naturally aspirated petrols. And if you turbocharge both of them, a petrol and a diesel engine, a petrol would beat a diesel hands down. Alas, there are not many turbocharged petrols avalable to derive empirical evidence.

Petrol all the way.

ps: On a side note, would people have opted for diesels even without the price advantage that it currently enjoys?
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