Petrol Engine or Diesel Engine: Your Choice?

[nozzlering]

What is a twin turbo or triple turbo engine? And how does it make the engine better than a single turbo engine?
As we increase size of turbo, the energy required to run it also increases. Which means, the turbo would be useless at lower rpms. So to get rid of this problem, smaller turbos are fitted. Smallest one works at low rpm. After that, the larger one cuts in to cater increased power needs.
Why diesel engine have low end torque while petrol engine not?
Diesel engines have heavier moving parts, heavier flywheel, heavier countrweights, has longer stroke length, to achieve higher compression pressures. Even at low speed or idle speeds, diesel engine works at good efficiency. There low end power output is high, hence low end torque is high.
Why petrol engine rpm is higher than diesel ones?
Petrol engines are comparatively lighter than diesel engines. They dont have to achieve high compression pressure like diesel engines. They have lesser inertia than diesel engines. They have shorter stroke lengths. Because of this, they can easily achieve higher rpms. Also, the calorific value of petrol is higher than that of diesel. So inspite of running at higher rpm, they lack the torque provided by diesel engines.
How is a petrol engine turbocharged?
It is more complex than diesel ones. Because here we have to deal with air/fuel mixture, instead of plain air. Another problem is, the fuel (petrol) will tend to burn earlier than required, causing detonation. I haven't studied about petrol turbocharging and, don't know much, how exactly petrol turbocharging is done.
Why petrol engine rev higher, still have less torque?
Answered above

My answers are not fully accurate. But I have tried on the basis of what I know. If someone can throw more light, most welcome.

 

[TSIVipul]

You both are seniors to me in the forum !!

When this happened??

After looking at your posts, I felt something friends.

If you look at the topic heading is Petrol Engine or Diesel Engine : Your choice

So it is as simple as if you like Mango then say 10000 reasons why you like it and you should not tell why you do not like the Banana

With this, I was bit afraid and scared looking your posts there how deep you have gone and there is no rope available to pull you back !! what to do

So come out quickly saying " All is well "

Don't worry buddy,Nozzle sirji is like a diesel engine teacher and hence I am free to fight with him on any question.And amazingly,being a teacher it is his duty to answer all my doubts,CALMLY

My answers are not fully accurate. But I have tried on the basis of what I know. If someone can throw more light, most welcome.

Got the answers and liked the fourth one most,it is just like the way I answer many people.You know what "MEETHI GOLI DENA",it is a very important part of any job or business.

 

[nozzlering]

^^I am waiting for answers and even better will be if you post some youtube videos.Because you may not believe me but I really can't get more than 75% of what I read.
Else please feel free of giving some weird examples and they are easy to understand.

I am also like you,not driven any triple turbo,BTW has BMW 535i got twin turbo?If yes,the I have driven one for 9 kms.
And yes,by this sentence I meant "Like you said that if one don't know the answers to the questions then he must not make comments" going by this way those who haven't driven twin/triple turbo powered cars must not make comments.(don't take it seriously please)

What I mean to say is, make a comment, when you have atleast some idea on what you're saying. If doing just for sake of a post, or to show something thats baseless, can't say.
I have given a fare idea in above post. Feel free to google, and you'll find many videos and writeups. Even then you cant get, then forget it. You've got other important things to do.

Vipul & Nozz

You both are seniors to me in the forum !!

After looking at your posts, I felt something friends.

If you look at the topic heading is Petrol Engine or Diesel Engine : Your choice

So it is as simple as if you like Mango then say 10000 reasons why you like it and you should not tell why you do not like the Banana

With this, I was bit afraid and scared looking your posts there how deep you have gone and there is no rope available to pull you back !! what to do

So come out quickly saying " All is well "

Thanks for concern gurrala. We have spent more time on this forum, that doesn't make me any superior. Yes. things have gone a bit far. And I feel its not at all fruitful. And using the rope you just threw, I am coming back.

 

[Gurrala74]

Oh Thank God. One is coming out !! the other will defenately come out behind him, because he is not the type to catch a rope, but to catch the rope catcher Nozz

See, you guys speak lot of technical stuff and really it is amazing knowledge sharing from one angle and other hidden angle in that was you are been dragged and dragged deep to the level of a live debate, so I just felt to say this to you and nothing more. Me being a old era mechanical engineer, studied something about IC engines and etc., but I always try and see that I post some thing called laymen language, I meant to say that whatever I post here others should understand it straight way. So that was my effort always which should be understood by every one in simple terms, because we cannot expect all the new car buyers are new members to the forum having lot of Automobile knowledge.

So finally I was actually looking at this topic to learn 10000 things about petrol engines and 10000 things about diesel engines and I am successful to learn few out of them, because of Vipul, Nozz, Codeman, Raja. Thank you all. Now continue again and all the good luck !!

 

[codename47]

Alright guys and girls enough debate

Lets have a nice weekend driving what you like.

I have to go check my skyline's heart transplant.

Punjabi has a line - Keha suneya maaf !

Enjoy your ride

 

[TSIVipul]

Oh Thank God. One is coming out !! the other will defenately come out behind him, because he is not the type to catch a rope, but to catch the rope catcher Nozz

Eh,wrong you are.I was sitting on the shoulder of Nozzle,have a look at my last post(I think its no.152) and you will read some lines saying "I have the right to fight with Nozzle".There is a complete list of five six people.I hope you won't ask me to disclose those names.

See, you guys speak lot of technical stuff and really it is amazing knowledge sharing from one angle and other hidden angle in that was you are been dragged and dragged deep to the level of a live debate, so I just felt to say this to you and nothing more. Me being a old era mechanical engineer, studied something about IC engines and etc., but I always try and see that I post some thing called laymen language, I meant to say that whatever I post here others should understand it straight way. So that was my effort always which should be understood by every one in simple terms, because we cannot expect all the new car buyers are new members to the forum having lot of Automobile knowledge.

So finally I was actually looking at this topic to learn 10000 things about petrol engines and 10000 things about diesel engines and I am successful to learn few out of them, because of Vipul, Nozz, Codeman, Raja. Thank you all. Now continue again and all the good luck !!

Leave it all aside,this has already killed the pace of the thread and stopped the fun-train.

Now let me today speak something in the favour of diesel engines,just from what have experienced.Pure desi experiences:-

• Diesel engines are weak till turbo comes to life and have a small powerband too,but they are really more powerful than petrol engines in that 1500-2000 rpm band of their rev range.More powerful than even turbo petrols.
• If you love driving with a light foot,then really petrol engines can't match the diesels.Or say for relaxed driving,diesels are really good.
• You always miss a diesel engine in the bumper-bumper traffic as in petrol you need to press both clutch and accelerator as well as brake too,but in diesel you need to adjust only clutch and slight press on brakes.
• When you are about to overtake someone and in a higher gear then for that sudden surge of power,diesel is more favourable.Just shift down,let the revs rise and feel the power push you back.Though petrols are also great but you have to shift down more than that of a diesel.
• For novices,diesel engines are a better choice.They are easier to drive at snail-pace.

And yes,whenever came the name of torque.I was always waiting you guys to mention one engine.The most brutal diesel engine fitted in any road-car till date.The most fierce power delivery any engine can offer.The only engine in the world which makes a 2.5tonne SUV feel like it is over-engined and make it feel like it will loose traction any moment.
You guys know which engine I am talking of?
Read these power figures and maybe you may fell off your chair:-
102 kgm of torque,or say 1020 Nm of torque that also spread between 1750-3500 rpm.
500 horses that also available at around 3000 rpm itself.

The car is Audi Q7 V12 TDI.I hope no one will ask me what is V12.

Rest now I am not against any engine,will speak in favor of both but still,minor competition is fair guys.

 

[nozzlering]

Tsi knows the advantages of Tdi, still he has to brag about petrol engines.
Well I didnt realize you're sitting on my shoulder. When!! I thought it was a fly!!
As far as your questions are concerned, bring them in. I will me glad to give answers to you.
Anyways, the competiton will be on, always. Because the competition is very close. Was either of two weaker, the game would have ended years back.

 

[VivekRj.Dieselhead]

Eh,wrong you are.I was sitting on the shoulder of Nozzle.

Didn't realized.

Now let me today speak something in the favour of diesel engines,just from what have experienced.Pure desi experiences:-

• Diesel engines are weak till turbo comes to life and have a small powerband too,but they are really more powerful than petrol engines in that 1500-2000 rpm band of their rev range.More powerful than even turbo petrols.
• If you love driving with a light foot,then really petrol engines can't match the diesels.Or say for relaxed driving,diesels are really good.
• You always miss a diesel engine in the bumper-bumper traffic as in petrol you need to press both clutch and accelerator as well as brake too,but in diesel you need to adjust only clutch and slight press on brakes.
• When you are about to overtake someone and in a higher gear then for that sudden surge of power,diesel is more favourable.Just shift down,let the revs rise and feel the power push you back.Though petrols are also great but you have to shift down more than that of a diesel.
• For novices,diesel engines are a better choice.They are easier to drive at snail-pace.

Sounds much fair now.

The car is Audi Q7 V12 TDI.I hope no one will ask me what is V12.

Rest now I am not against any engine,will speak in favor of both but still,minor competition is fair guys.

No i won't ask at least. Yeah it is actually good to have some competition, leads to enrichment of knowledge.

Anyways, the competiton will be on, always. Because the competition is very close. Was either of two weaker, the game would have ended years back.

I totally agree with you bro.

 

[TSIVipul]

Tsi knows the advantages of Tdi, still he has to brag about petrol engines.

Take it this way:Every car owner knows the pulling power of tractor,but that doesn't mean that the car owner loves the tractor.

Well I didnt realize you're sitting on my shoulder. When!! I thought it was a fly!!

Say thanks to my light weight.

Anyways, the competiton will be on, always. Because the competition is very close. Was either of two weaker, the game would have ended years back.

+100,after soem years only petrols will be declared better!!

Didn't realized.
Sounds much fair now.

Oh,I speak in favour of diesel and it FAIR!!And if I speak in favour of petrol then it will sound 'better',not only 'good'.

No i won't ask at least. Yeah it is actually good to have some competition, leads to enrichment of knowledge.

Don' take only Q7 V12 TDI,there are cars like Koenigsegg Agera and BV(Bugatti Veyron) which produce far far higher power and torque than Q7.Also the linear power delivery don't make them as brutal as the Q7 V12 is.This is how the power of petrol engines is more usable.

 

[Ceekay]

In India its got to be Diesel for me, and you know the reason, yes low cost of fuel.
If I am in a Middle East country no way I will hate petrol, yes its got to be Petrol outside India.

My point is choose wisely, and enjoy driving

CK

 

[VivekRj.Dieselhead]

Take it this way:Every car owner knows the pulling power of tractor,but that doesn't mean that the car owner loves the tractor.

You are trying to use spark plug besides petrol container. While every thing is cooling down.

Even jets use petrol(somebody said petrol instead of jet fuel), does it mean you can use it normally on any expressway?

+100,after soem years only petrols will be declared better!!

Its a dream won't come true, at least in india.

Oh,I speak in favour of diesel and it FAIR!!And if I speak in favour of petrol then it will sound 'better',not only 'good'.

Just because you were trying to put forward pros. and cons. of both the engines.

Q7.Also the linear power delivery don't make them as brutal as the Q7 V12 i

that,s because of basic diff in working procedure b/w diesels & petrols.

 

[codename47]

In India its got to be Diesel for me, and you know the reason, yes low cost of fuel.
If I am in a Middle East country no way I will hate petrol, yes its got to be Petrol outside India.

My point is choose wisely, and enjoy driving

CK

Absolutely

Thats how it is man .
You have to choose wisely

Up here in australia diesel is same price as petrol and I don't see point where I have to go get myself a Diesel car here , for the same amount of money I can get a petrol car and that too from a variety of sellers.

Diesel head & Vipul guys take it easy

 

[vaibhav]

My dezire ldi is giving me 14 km now and my ac maruti used to give 11-12 km /pl
Diesel anyday if we consider costs

 

[jihu123]

If the diesel engine had a good exhaust note, high revving capability, less engine sound & no turbo-lag (I know there are many cars which doesn't have turbo-lag). Then I would have surely opted for the diesel with the consideration of the extra torque.

But unfortunately, diesel is not providing the requirements I prefer. So I will still stick on to petrol cars despite the ease-to-drive in traffic or hills. It's fun for me to rev hard, change gears often etc.
I guess many diesel owners prefer them due to their low running costs (I agree to this considering the rising petrol prices) & the ease to drive in traffic/hills (why not the automatic?).

 

[TSIVipul]

You are trying to use spark plug besides petrol container. While every thing is cooling down.

Ah yes,petrol engines work with the help of spark plug only.BTW,what was cooling down?This spark plug thing gives them a very very big advantage in the COLD weather where you need to keep your diesel engines started for even hours during night time.Just start your petrol car and leave,not like the diesels who keep their engine started for hours.
Go and see in Badrinath,Gangotri,Manali,Rohtang,Ladakh etc the condition of diesel owners.

Even jets use petrol(somebody said petrol instead of jet fuel), does it mean you can use it normally on any expressway?

IF jets will use diesel then:-
Your ears will get blown away by the sound.
Just think,the jet is doing 300 kph and turbo starts and it will suddenly reach 400 kph in 1 second.Result:2-3 passengers dead due to heart attack.

Its a dream won't come true, at least in india.

Hmmm,+100-agree.

My dezire ldi is giving me 14 km now and my ac maruti used to give 11-12 km /pl
Diesel anyday if we consider costs

If you consider costs,and what about other factors?

If the diesel engine had a good exhaust note, high revving capability, less engine sound & no turbo-lag (I know there are many cars which doesn't have turbo-lag). Then I would have surely opted for the diesel with the consideration of the extra torque.

But unfortunately, diesel is not providing the requirements I prefer. So I will still stick on to petrol cars despite the ease-to-drive in traffic or hills. It's fun for me to rev hard, change gears often etc.
I guess many diesel owners prefer them due to their low running costs (I agree to this considering the rising petrol prices) & the ease to drive in traffic/hills (why not the automatic?).

+100,agree on all points.