[mxx]

Considering that unlike before the newer generation diesels are more responsive and give better performance

1. When you have a choice of petrol or diesel, which one would you choose from a purely for performance? I repeat purely from performance perspective costs including fuel costs are NOT an issue for the choice.
And consider cars above the 25lakhs mark because below that there is no choice of good petrol and good diesel within same model.

2. Why is it that with all the advancements in diesels, petrol is still used in racing circuits? If I am not mistaken only audi has a successful diesel in the racing arena. And no track or street racers prefer diesel.

[Shan2nu]

1. When you have a choice of petrol or diesel, which one would you choose from a purely for performance? I repeat purely from performance perspective costs including fuel costs are NOT an issue for the choice.
And consider cars above the 25lakhs mark because below that there is no choice of good petrol and good diesel within same model.

For pure performance, id choose a petrol. No doubt diesels are getting quicker by the day but thats where the prob lies. They are only getting quicker without the fun factor.

When i rip a car through its gears, i want the engine to scream its heart out. The sensation of driving a high reving petrol engine is a different experience altogether.

2. Why is it that with all the advancements in diesels, petrol is still used in racing circuits? If I am not mistaken only audi has a successful diesel in the racing arena. And no track or street racers prefer diesel.

The prob with diesel engines is that they still depend on "Forced Induction" to compete with petrol engines.

The Audi that you mentioned is FI, the Seat diesel that won the WTCC championship last year was FI. But not all forms of racing allow FI and thats where the diesels suffer.

Shan2nu

[raj_5004]

with the new generation diesels getting faster as well as more fuel efficient than their petrol siblings, i feels diesels have an edge.

i dont have to redline the engine & the enormous torque wave pushes me to unbelievable speeds, thats where the fun lies!

[R2D2]

Undoubtedly diesels have their advantages, efficiency is the primary one. And they are closing the gap with petrol engines in NVH and power.

But for sheer performance it is petrol. If diesel engines were all they are made out to be, then F1 would be running diesel engines. My 2 cents.

Cheers

[raj_5004]

the JCB dieselmax shows what a diesel can do-
JCB DIESELMAX

[dustom_99]

most prestigious 24 hr race LE MANS is not only running AUDI diesel but it has won the event twice in recent years ,putting all other gas guzzlers to shame.a diesel engine with same CC as for petrol ones,and all the same rules regarding forced induction and ecu/ecm etc, so the point that diesel engine is force induced does not stand a chance,who is barring petrol once from using a turbo,no one is! but "DIESEL IS THE NEW PETROL"

[reignofchaos]

Originally Posted by dustom_99

most prestigious 24 hr race LE MANS is not only running AUDI diesel but it has won the event twice in recent years ,putting all other gas guzzlers to shame.a diesel engine with same CC as for petrol ones,and all the same rules regarding forced induction and ecu/ecm etc, so the point that diesel engine is force induced does not stand a chance,who is barring petrol once from using a turbo,no one is! but "DIESEL IS THE NEW PETROL"

The reason why diesels are preferred in endurance races is not because of their power characteristics but rather their fuel efficiency. Diesels need to do only a third the number of stops compared to petrols because they are more fuel efficient and hence win when a race is being done over a very long distance.

When FE/number of pitstops is not a concern, a petrol engine will cane a diesel.

[RX135]

Depends on how you look at it.

Modern CRDi Diesels are perceived to be more powerful than Petrol ones. But, that's because we typically compare turbo-charged diesels with NA petrol engines. Bring in Turbo Petrols and suddenly, diesels lag behind as they used to earlier.

If we look at similar powered diesel and Petrol engine (irrespective of turbo and displacement), diesel will always hold advantage. That is because diesel produces torque at much lower band and will be quicker. So a diesel with 100bhp engine would be faster than petrol with 100bhp engine.

[dustom_99]

I guess it isnt only about KMPL,it is a factor of course, but you typically get twice the torque at half the revs, with advancement in turbo tech, variable turbine thingy and ecu governed bov s, you get that massive almost tank pulling torque right from low end rpm(almost idle rpm for petrol ones) till almost the red line, and some mordern diesel engines now have red lines pretty close to petrol ones.Top torque through out the rev band quitely(without much bling bling ) means The car hits and gets out of every corner while its on its top torque and pulls till redline with almost same torque,while the petrol one one the exit will be either in its power band(which is already quite near to red line) or out of it,then quite soon either you will have to upshift or will have to downshift.


when comparing Turbo petrol to turbo diesel,we must also keep in mind the petrol turbo costs almost 3 times of diesel turbos,because they encounter higher specific temps hence metallurgical need are far exoctic,and that means you would be comparing petrol and diesel engine according to there specs, there will be a huge cost difference in both the engines. so plain n simple,they dont belong to same segment of cost and R&D hence should not be compared

[pgsagar]

Originally Posted by RX135

Depends on how you look at it.

Modern CRDi Diesels are perceived to be more powerful than Petrol ones. But, that's because we typically compare turbo-charged diesels with NA petrol engines. Bring in Turbo Petrols and suddenly, diesels lag behind as they used to earlier.

If we look at similar powered diesel and Petrol engine (irrespective of turbo and displacement), diesel will always hold advantage. That is because diesel produces torque at much lower band and will be quicker. So a diesel with 100bhp engine would be faster than petrol with 100bhp engine.

I agree with the first part. They trick up modern diesels with all kinds of gizmos like turbo, intercooler etc. etc. Do the same to petrol and it will say sayonara to diesels.

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.

[raj_5004]

i guess it would be fair to compare say a BMW 5 series- both petrol & diesel. the diesel has better acceleration, driveability as well as fuel efficiency at the same or lower cost.

[Torque-ative]

Gasoline rules !! No question...case in point my antiquated 2.2 liter hurricane 3B.
Slip it into low rato 2 and then watch her scream like a Bazai runner ,..no make that a Stuka dive bomber !!!

I am still new into the jeep scene,...you have to watch Sarvinder Mod (NIOC) with his willys MB. There is no terrian that he has'nt kicked *** in...& thats thanks to pure Petrol power !

[CPH]

Originally Posted by reignofchaos

The reason why diesels are preferred in endurance races is not because of their power characteristics but rather their fuel efficiency. Diesels need to do only a third the number of stops compared to petrols because they are more fuel efficient and hence win when a race is being done over a very long distance.

When FE/number of pitstops is not a concern, a petrol engine will cane a diesel.

Sorry, but you aren't up to date.

In the 2008 24 hour race the the tanks were reduced in size for the Diesel engines in order to force them to have as many tank stops as the petrols.

They also had a big tyre disadvantage due to the 250kg (925kg) more than the other cars at 675kg.

Dispite the handicap the Audi in the lead finshed the race over 200 miles ahead of the fastest petrol.

I have the Audis and the Peugeots seen competing and they were unbelievable fast and the sound was great.

I like petrols but I would go for a performance Diesel powered car if I would go bigger than a shopping trolley (which my preferreed cars are).

[BuBooMan]

IMO its petrol all the way. Point in case the Skoda Laura : 1.8 TSI vs 2.0tDI. Diesel thrashed. BMW 530i incinerates the 530d. So many more examples to follow. And I know people will tall about usable power, all top end power and diesel torque curves. A quick diesel will give you that underdog rush. But the feeling a revvy gas guzzler gives is unparalleled. Ah the 8000 rpm red line, the throaty roar, the buzzing mill which feels like its connected to one's right foot. Epic! Now only if petrol was cheap and the quality was good. Well you win some, you lose some. 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.

[raj_5004]

Originally Posted by BuBooMan

IMO its petrol all the way. Point in case the Skoda Laura : 1.8 TSI vs 2.0tDI. Diesel thrashed. BMW 530i incinerates the 530d. So many more examples to follow.

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