Guide: How To Drive and Maintain a Diesel Car?


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raj_5004

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The title of this thread is self explanatory. Many of us know how to drive cars. And what's so special in driving a diesel car? But I got a request from a fellow member that we should have a thread regarding this so that we all can share our knowledge on this aspect. Also, I do feel that there are some minor differences in driving a petrol & a diesel car. Please note that this is not a petrol v/s diesel engine thread.

Which one is more difficult to drive?


Now, the norm is that, petrol cars are easier to drive. But, I beg to differ. This holds true in the previous generation diesels which were lethargic, had a heavy clutch & gearshifts and also had cold starting issues and the likes. With modern CRDi engines, I personally feel that, with the enormous torque in hand, diesel cars are much more easier to drive in cities as well as highways. But that's just my personal opinion.

Advantage Diesel.


Diesel engines have more torque. So in city traffic or stop & go driving, more often that not, you dont need to use the throttle. Many people find starting the car on uphills a pain. In petrol, you need to use the throttle, clutch & brake judiciously to avoid the car from rolling back. But in diesels, you dont need to use the throttle at all. Just co-ordinate between the brake & clutch & off you go!

Disadvantage Diesel.


Almost all the diesels in our country are turbo charged engines. So you need to get used to the sudden turbo surge (sudden acceleration when the turbo kicks in) when accelerating. Diesels dont have a linear acceleration like petrols. Also, the powerband in diesels are quite narrow. For example, a typical petrol has a powerband right from 2500 rpm to 5500 rpm. But in most diesels, the powerband is from 1500 rpm to 3500 rpm. Do note that diesels have their torque right from as low as 1500 rpm.

How to start a diesel car?

1) Diesel engines dont have spark plugs. They rely totally on the battery to start the engine. So, never ever start the engine with AC on. Maybe you can even consider switching OFF the radio before cranking.

2) Since diesel engines dont have spark plugs, they have a pre-heating mechanism. In simple terms, look for the pre-heater warning symbol in your instrument console. It will come on as soon as you turn ON the ignition and will go off after 3-4 seconds. Crank your engine ONLY after this sign is off. This is not applicable for all diesel cars.

3) A diesel engine is very very heavy. The starter motor has to work hard to crank your engine to life. Be considerate to the starter motor. Depress your clutch every time you crank. This disengages the gearbox from the engine, making it a little easier for the starter motor to crank your engine, thereby prolonging its life.

4) Turbo idling - very important. Every turbo needs idling. After you have started the engine, wait for a minute for the turbo to warm up. Never ever rev the engine immediately after starting it. Also, after a long drive, wait for a minute before you switch the engine off.

How to drive a diesel car?


1) After all the above points are done, similar to a petrol car, never rev a diesel engine too much while driving, till it reaches the operating temperature. A diesel engine may take longer to reach it's operating temperature.

2) Do not unnecessarily rev a diesel engine till 4-5k rpm. There is no point. It will simply make noise without any acceleration. You are also burning precious fuel. Work on the enormous torque instead. Shift up at 3k rpm, shift down if you go till 1.5k rpm. Petrol car drivers will be amazed at the response because, by doing this, you are always in the turbo range.

3) At the same time, do not always drive below 2000 rpm, even though that is possible (torque!). Diesel engine leave a lot of soot (burned fuel carbon residue). This gets accumulated in the exhaust. Once in a while, when you rev your diesel all the way till 4000 rpm, you will see thick black smoke from the exhaust. This is perfectly normal & you have cleared the accumulated soot in the exhaust.

4) When you are stuck in stop-go traffic on an incline, dont get worked up by using the half clutch method, to prevent the car from rolling back. You are unnecessarily burning the clutch. Again, because of the torque of diesels, it is really very easy to get a diesel car moving on a slope. Even on sharp inclines, all you need to do is leave the clutch slowly & the car moves ahead. No throttle is required at all.

5) First gear of a diesel car is very very short. In a petrol car, you can use the first gear even till 20-30 kmph. In diesels, downshift to second as soon as you reach 10-15 kmph. Then the torque will easily pull you through. If you rev in the first gear, the car will jerk on your throttle inputs. The upside is, if you want to coast slowly, just engage a gear & leave the clutch, brake & throttle. A diesel car can coast endlessly without stalling, without any throttle input.

Any special maintainence/precautions required?


I know this is a driving only thread, but it is essential to mention this. Diesel cars have a mechanical pump, except high end diesel cars, which have an electronic pump. NEVER LET YOUR ENGINE RUN DRY. Because if you choke and stall your engine, you will have a hard time. After you fill in diesel, you will have to manually pump the fuel pump till your engine starts. To counter this, Fiat Punto electronically stalls the car when there is 2-3 litres of fuel left in the tank, so that the owner does not have to pump the fuel pump. This maybe applicable in some other cars as well.

Want to show off diesel torque?


Pick a car with a good diesel engine like Scorpio's mHawk, Vento's TDi, etc. Take the car on a uphill and stop it midway. Then fill your car with passengers. Then slot into 3rd gear. Then, with the AC on, give a little throttle and leave your clutch carefully and see your diesel car moving forward without a hiccup! Ask your petrol savvy friends to try this in their car!
Caution: Doing the above will burn your clutch.

Do diesel engines require heavy maintainence? No.
Are diesel cars noisy? Not exactly.
Are diesel cars fun to drive? Depends on your driving style.
 

TSIVipul

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Re: How to drive a diesel car?

Weather its diesel or petrol,my rule is simple:-
Start the car,idle it for a minute and move on..
After moving some distance any sensible driver will understand which part of the powerband is for what sort of driving.
For example:In turbo diesel cars:
Lower end:No power,no torque..this is for relaxed driving,or for city traffic.
Mid range:Full of power and earth moving torque...this is for highway driving when you need sudden bursts of power and hilly driving etc
Top end:Again a big part of power goes off..this is only for high speed cruising,or for hilly driving on steep inclines,although its a fact that a swift pulls better in second gear at 3500 rpm than in first gear at 5000 rpm because engine feels strained there and tends to bring down its revs itself.

So after I understand the powerband after driving the car for a couple of kilometers,now I drive my way,and what is my way?It is as follows:-
Whatever the car is,it performs best when in powerband of the rpm range,hence I never drive considering what gear,I always drive considering RPM and try to be on a fixed rev range.Most of the time 2500-3500 rpm for diesel cars.
 
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Re: How to drive a diesel car?

Thanx a lot for your effort raj sincerely appreciate you effort. My question to you and vipul and other experts is what exactly is turbo lag ? How does 1 recognize that the car has turbo lag ? How to overcome it in bumber to bumber traffic ?
 

TSIVipul

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Re: How to drive a diesel car?

Which one is more difficult to drive?[/B]

Now, the norm is that, petrol cars are easier to drive. But, I beg to differ. This holds true in the previous generation diesels which were lethargic, had a heavy clutch & gearshifts and also had cold starting issues and the likes. With modern CRDi engines, I personally feel that, with the enormous torque in hand, diesel cars are much more easier to drive in cities as well as highways. But that's just my personal opinion.
Yeah,only issue is till the turbo comes to life,before that,all the diesels are lethargic and underpowered and you need to work on clutch and throttle to move them in dense city traffic.Right buddy?Yes,its a fact that weak low end of petrols make them also painful in city,but still petrol cars with good low end are easier..
In my opinion,turbo petrols are the easiest cars to live with.


Want to show off diesel torque?


Pick a car with a good diesel engine like Scorpio's mHawk, Vento's TDi, etc. Take the car on a uphill and stop it midway. Then fill your car with passengers. Then slot into 3rd gear. Then, with the AC on, give a little throttle and leave your clutch carefully and see your diesel car moving forward without a hiccup! Ask your petrol savvy friends to try this in their car!
Caution: Doing the above will burn your clutch.
Buddy,it looks like you are still to drive in 'true' hilly roads.Those ghats are not the roads which I am talking of,just once drive on the hilly roads of Uttarakhand,J&K,Himanchal etc and you know what,you won't be able to even engage the third gear for most of the time.Why?Because your speed and the inclines,none will allow you to engage the third.
Example:On the way to Badrinath,there is a place called Hanuman Chatti,at that place I have seen the cars like Cruze also stall if the driver makes even a small mistake and then leave the second gear,its the game of first gear then and if the driver is not good at negotiating such inclines then the situation worsens even more..


Thanx a lot for your effort raj sincerely appreciate you effort. My question to you and vipul and other experts is what exactly is turbo lag ? How does 1 recognize that the car has turbo lag ? How to overcome it in bumber to bumber traffic ?
Turbo lag...hmm[thinking],if turbo charger is an interesting thing,then turbo lag is even more interesting.

What is turbo lag?
Simple it is,your turbo charger consists of a compressor ran by a gas turbine.And this gas turbine is ran by the pressure of your exhaust gases.Now to have the enough pressure for running turbo you need enough pressure of gases.That pressure is attained when your car nears 2000 rpm(may be any rpm range,even 1000 rpm too).
That meant until the engine reaches 2000 rpm,the turbine will not run and as a result turbo will also not run.this phenomenon is called 'turbo lag'.Or say,the rpm range till which the turbo doesn't work and engine works like a naturally aspirated one is called turbo lag.

How to recognise turbo lag?
Simple it is,take a Swift and engage second gear very shortly so that the car will be in second gear at just 1200-1500 rpm(below that the car engine stall)now start accelerating and you will notice that as soon as the engine nears 2000 rpm,the car will give a sudden burst of power and move ahead like a pro.Do this in third one and you will understand it even better way because you will get more time to feel it.In the turbo lag,the car refuses to move up with more force and RPMs does not increase swiftly,in other words,in turbo lag the engine RPMs also does not rise like they must.And hence the engine stalls.

How to overcome it?
Very simple it is,while driving in bumper to bumper traffic,keep your right hand on the steering wheel and using your left hand try to find out a short vertical stick near your left thigh.This stick is called 'gear lever':biggrin:,catch this stick and move it in a lower gear.And you will see,turbo lag is vanished.
In other words,only one way to encounter turbo lag is SHIFT DOWN.Driving on half clutch is not advisable.
 
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Re: How to drive a diesel car?

I dont know if I am doing wrong way please clarify: Punto90 is case.

I move the car releasing the clutch-1st gear and then gradually press throttle.

mostly i shift up at 1500-1800 rpm.

I love cruising in 5th gear at 50 -70kmph i.e 1600rpm.

I never go above 2000 rpm unless required for sudden overtake or such situation

I doubt i ever revved more than twice or thrice above 3500rpm.

so how much did i harm my MJD since 20k km on odo ?
 
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Re: How to drive a diesel car?

A noob question . What exactly is cranking the engine.
Is it like starting?
And what is the meaning of cranking on a cold start?
As to my understanding crank is starting your engine and cold start is early morning start when the engine is cold.
 

TSIVipul

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Re: How to drive a diesel car?

I dont know if I am doing wrong way please clarify: Punto90 is case.

I move the car releasing the clutch-1st gear and then gradually press throttle.

mostly i shift up at 1500-1800 rpm.

I love cruising in 5th gear at 50 -70kmph i.e 1600rpm.

I never go above 2000 rpm unless required for sudden overtake or such situation

I doubt i ever revved more than twice or thrice above 3500rpm.

so how much did i harm my MJD since 20k km on odo ?
Buddy,you are not doing any harm to your engine.
What you are doing is that your engine in the said rev range works like it has no turbo.It works like a N/A engine and and does its job in a very much relaxed way.
Still,as much I have heard its better if you increase your rev range a bit and start shifting up at about 2000-2200 rpm.This will make the turbo run too and will help you a lot as then you will have to make very less gearshifts.And yes,the FE will also increase a bit.


A noob question . What exactly is cranking the engine.
Is it like starting?
And what is the meaning of cranking on a cold start?
As to my understanding crank is starting your engine and cold start is early morning start when the engine is cold.
Haha,even I am also weak at answering this question.So let the Raj come back and start the tut classes for us.
As per me:Cranking means starting starting the engine(I think the starter motor runs the crank and hence its called cranking)..
 

350Z

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Re: How To Drive and Maintain a Diesel Car?

Great Article. Now Moved to The Automotive Library.

Drive Safe,
350Z
 
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Turbocharger is running at all rpms. A turbocharger is a high precision piece of engineering. And it starts rolling at slightest gust of exhaust gases. But the pressure developed by it is significant enough only at around 1800 rpm (or above this rpm).

You are right Vipul. "Cranking" means turning the crankshaft of the engine with external aid (by starter motor). Sometimes its done by pushing the car. Cold start is just a condition. You still have to crank it to bring it to life. [:)]
 
Thread Starter #10

raj_5004

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Re: How To Drive and Maintain a Diesel Car?

Weather its diesel or petrol,my rule is simple:-
Start the car,idle it for a minute and move on..
That's a nice habit.

For example:In turbo diesel cars:
Lower end:No power,no torque..this is for relaxed driving,or for city traffic.
Not true for all diesels. Yes, in my Punto, the low end is terrible. But in mHawk, TDi, D-4D, etc... even the low end is great. Just that, you wont get the kick of the turbo, but it wont be lethargic.

Thanx a lot for your effort raj sincerely appreciate you effort. My question to you and vipul and other experts is what exactly is turbo lag ? How does 1 recognize that the car has turbo lag ? How to overcome it in bumber to bumber traffic ?
Turbo lag. Okay...

Take a diesel car which is know for turbo lag, for example- Punto, i20, Cruze, etc. Now accelerate the car till say 40 kmph. Suppose you are in 3rd gear. Now slow down the car till maybe 20 kmph. Do not downshift to 2nd. Now press the throttle. You have now hit a dead spot. Even if you stand on the throttle now, the car wont accelerate. This is because the turbo is not active now, simply because you are not in the right gear/rpm.

To overcome turbo lag, all you have to do is be in the right gear at the right time. Its not a big deal as it sounds!

The technical answer to the above - Vipul has already answered it.

Yeah,only issue is till the turbo comes to life,before that,all the diesels are lethargic and underpowered and you need to work on clutch and throttle to move them in dense city traffic.Right buddy?
Again, depends on the engine also. Good diesel engines have a wider torque spread which ensures you dont need frequent gearshifts.

For example, Innova & Punto. You have driven both. Punto needs more gearshifts than Innova.

I dont know if I am doing wrong way please clarify: Punto90 is case.

I move the car releasing the clutch-1st gear and then gradually press throttle.

mostly i shift up at 1500-1800 rpm.

I love cruising in 5th gear at 50 -70kmph i.e 1600rpm.

I never go above 2000 rpm unless required for sudden overtake or such situation

I doubt i ever revved more than twice or thrice above 3500rpm.

so how much did i harm my MJD since 20k km on odo ?
There is nothing wrong in what you are doing buddy. Only thing is, you turbo must be in hibernating mode now, since you have rarely used it!

Once in a while, you do need to rev it. Dont unnecessarily keep revving it for long durations. Dont even rev it till 4000 rpm. Short bursts till 3000 rpm once in a while will also do. You have a turbo diesel, use the turbo !!!

A noob question . What exactly is cranking the engine.
Is it like starting?
And what is the meaning of cranking on a cold start?
As to my understanding crank is starting your engine and cold start is early morning start when the engine is cold.
After ignition, when you twist the key to start the engine, it is called cranking. Yes, basically cranking is starting the engine.

Cranking on a cold start is equivalent to cold starting.

As per me:Cranking means starting starting the engine(I think the starter motor runs the crank and hence its called cranking)..
Actually, it has nothing to do with the starter motor.

Dictionory says, 'cranking' means to get a machine started. I think it originated from the era when old cars used to have this long lever protruding from the bonnet, which you have to rotate to start the engine. Basically, that lever was connected to the crankshaft.

Anyways,

crank = A device for transmitting rotary motion, consisting of a handle or arm attached at right angles to a shaft

cranking = To start or operate (an engine, for example) by or as if by turning a handle

crank up = To cause to start or get started as if by turning a crank

Great Article. Now Moved to The Automotive Library.

Drive Safe,
350Z
Thank you buddy.
 
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Re: How to drive a diesel car?

A noob question . What exactly is cranking the engine.
Is it like starting?
And what is the meaning of cranking on a cold start?
As to my understanding crank is starting your engine and cold start is early morning start when the engine is cold.
Thats correct.

Cranking is now a days switching on or starting the engine.
In earlier days, one had to crank the engine with the help of a crank shaft to turn on engine to life.

Cold start is starting the engine after a long intervel - normally it is morning. Any time of the day if we start the engine for the firt time after long resting/switch off time, then it can termed as cold start.
 
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Re: How To Drive and Maintain a Diesel Car?

I beg to differ Raj. As you said cranking was done earlier to start the engine, using a handle. That lever has been replaced by starter motor. I feel it has to do with starter motor, or any device or means which is used to turn a engine for starting purpose.

Thanks

Actually, it has nothing to do with the starter motor.

Dictionory says, 'cranking' means to get a machine started. I think it originated from the era when old cars used to have this long lever protruding from the bonnet, which you have to rotate to start the engine. Basically, that lever was connected to the crankshaft.

Anyways,

crank = A device for transmitting rotary motion, consisting of a handle or arm attached at right angles to a shaft

cranking = To start or operate (an engine, for example) by or as if by turning a handle

crank up = To cause to start or get started as if by turning a crank



Thank you buddy.
 
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Nice work Raj!

In my opinion modern day crdi diesels are almost petrol car like , and don't feel very different like in terms of gear shift quality, clutch travel,though there are exceptions I think.

My mother now feels our beat petrol is more comfortable to drive than our swift diesel.At first she did feel that swift diesel was more comfortable than our beat petrol,but it changed.The reason is turbo lag.I its because of multijet 75hp.But my mother definitely feels the swift is more fun to drive though.

Tackling the turbo lag is quiet easy as the downshifting is easy in a car like swift with a slick and throw gearshift and a short clutch.

I am a diesel head in city and a petrol head in highway.

To me the clatter or idle noise of a crdi diesel resemble me very good low end torque!

BTW,our swift is redlined once in a while and is rarely driven below 2000rpm.I feel our swift's mjd is more eager to rev than the petrol heart of beat.
 
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