Guide: How To Drive and Maintain a Diesel Car?


TSIVipul

Honoured Member
Joined
Aug 6, 2011
Messages
6,203
Likes
4,213
Location
Meerut, U. P.
Vipul, I will try to explain you the difference between FGT and VGT.
Basic principle of a turbocharger in layman's term. A turbine is directly coupled to a compressor(blower). Exhaust gases make the turbine rotate, which in turn rotates the blower. This blower compresses the intake air and supplies air in excess to combustion chamber. The exhaust gases are introduced to the turbine blades via a set of nozzles. The angle of these nozzles determine the gas pressure. More pressure, faster the turbine will rotate and vice versa.
When the angle of nozzles is fixed it is FGT. In FGT max power and efficiency range is limited.
But latest technology is that the angle of nozzles can be varied on the basis of external factors. In this case, max power and efficiency range is more widespread.
Thanks a lot buddy,now I can say that I have really understood what the difference is.
I rate it as a 5-star(*****) tutorial...(somewhere TAI is a college too.a lot of technical terms can be learnt here)..[:)]

I was explained in laymans term that turbo Chargers introduce nitrogen (NO) in the combustion chamber. Is it right or incorrect?
Now don't tell me buddy that you meant NOS,the fast and furious thing...:biggrin:


Ok guys first extremely sorry if iam talking something silly or making silly comparisons so far what I have understood about turbo lag in cars is
Lets take example of Scorpio and safari , people say scorpio is easy to drive in city does it mean that if you are at 40kmh on 3 gear and you brake and the speed comes to 20 you can still continue driving without shuddering the Scorpio and then slowly build the speed to 50 and then shift to 4th gear ?

But if the same example happens with safari you have to downshift on 2 gear then again build the speed to 40 upshift to 3 then 50 and 4th because if you don't the safari will shudder and may stall ? Can some 1 answer this please
.
Raj thanx for creating this thread this will be of immense help for the members and you vipul and others are doing great job and will be great if you guys can give some real world examples like the one raj and vipul gave about turbo lag and other topics which will pop in it gives a better understanding and more easy to grasp alongbwith technical words.
What is silly in the comparisons you are making?And sorry for what?....we are here to learn and making mistakes is our birth right,there are a lot of people to correct them..:lol!:
About the Scorpio and Safari Query,here are three factors:-
1):Kerb weight:-
  • Innova D-4D weighs about 1680 kg.
  • Scorpio weighs about 1850 kg.
  • Safari weighs about 2040 kg(4X2) and about 2170 kg(4X4).
So the weight difference is about 460 kg between Safari and Innova and 190 Kg between Safari and Scorpio and this net weight difference helps the Scorpio a lot.

2):Engine power and torque delivery:-
  • Toyota D-4D is having the best low end torque of three and hence requires least gearshifts in the city(since Innova is lightest too).
  • Mahindra mHawk is having a fantastic torque spread from about 2000-3500 rm and hence this engine offers fantastic responsiveness in mid range.In fact since any car spends most of its life in the mid range only and this car has the best of it,that's the reason mHawk is known for its responsiveness.Am I right Raj?
  • Tata 2.2 VTT DICOR is the only engine to have a VGT here and hence it offers best of its performance between 27-2800 to 3900-4000 rpm,but no doubt this engine pulls like a pro in this range.In other words this engine is having a better higher-mid-range.Hence Safari don't has as good low end as Scorpio or Innova and the added weight of Safari worsens it even more.
None of these engines have got a meaty top end,all experience a tail off in the power there.Innova feels most strained,mHawk second and 2.2 VTT feels least strained..

3):Gear ratios:-
  • Gear ratios can make or break a car in terms of performance.Example:A swift has got better acceleration then Indica Vista and Punto 90 HP.Why?This is the magic of gear ratios.In other words a car with 50 bhp and perfect gearing can eat up an another one with 100 bhp but imperfect gearing.
  • Toyota Innova has got longer second and third gear as compared to first,fourth and fifth.Due to this Innova can cover a wide speed range in these gears and hence can cover a whole city in second or third gear itself and since the engine has good low end,so it helps even more.
  • Mahindra Scorpio has a shorter first gear with second gear longest and third gear slightly shorter than the second one and again with good low end of engine,the second and third gears do well in city.
  • Tata Safari has got a shorter first and Second gear(shorter than Scorpio and Innova,still its quite long) as well as the third is long but its meant for cruising(its not for 20-80 kph but its for 60-120 kph).And hence the Safari is more favorable as a cruiser or mile muncher.
I haven't considered 4th and 5 th gear as its longer in every vehicle and are meant for cruising only..


Nice Thread. Anyone can give me info on the petrol & diesel engine maintenance costs? Why do people always say that diesel is only good if you drive daily for about 50kms?
These are the old school myths.Now a days diesels are just slightly more expensive on maintenance as compared to petrol.And about the 50 kms per day theory,you can have a CRDI and park it at your home and use it once a week,it will be in the pink of health always.
Actually the second reason for 50 kms/day is that it means 1500 ksm per month and hence diesel will prove far more economical than its petrol sibling.

Yeah. That's what they meant. Scorpio has a good low end torque & even the Innova goes smooth at 40km/h on 4th gear!
Absolutely right.Its longer 4th gear shows its magic here.
 
Joined
Nov 1, 2010
Messages
4,237
Likes
372
Location
Kannur,Kerala
Gear ratios can make or break a car in terms of performance.Example:A swift has got better acceleration then Indica Vista and Punto 90 HP.Why?
A good Auto enthusiast never relies on paper figures to conclude performance of a car.

In your case I am forced to believe you have followed the path of ignorance.
just do not post a comment for the sake of comment. it may sound very amateur and boring.

in gear acceleration of 90hp punto and indica vista is better than swift. it is always better to have in gear acceleration handy than 0-100kmph figure.
This is the magic of gear ratios.In other words a car with 50 bhp and perfect gearing can eat up an another one with 100 bhp but imperfect gearing.
aren't you exaggerating ?
this is a automotive forum. above comment was very childish.
i can understand what you meant is 50kmph car is having perfect gears and 100bhp one is having worst ..but that is worst example one can give and totally off topic here.
 
Joined
Feb 28, 2012
Messages
7,026
Likes
2,846
Location
Mumbai
Guys in the Aria on the rpm meter there is green zone from if I recollect marked from 2000 rpm to 3500 rpm is this green zone to let the driver know where the peak torque lies and once you reach this zone you can ufshift and when you fall below this you can downshift ?
 
Joined
Apr 6, 2012
Messages
876
Likes
187
Location
F Deck
The approach to my apartment is sort of a dirt road (about 300 m), full of uneven surface, inclines. Last night, when I was coming back home on my Manza (4 adults, 2 kids and some luggage), engaged in 1st gear and let car propel on its own (without using accelerator pedal). I was surprised that the car brought me home through the ups and downs, effortlessly. My wagon r would stall in this condition.
Is it because of high torque of a diesel engine?
 

TSIVipul

Honoured Member
Joined
Aug 6, 2011
Messages
6,203
Likes
4,213
Location
Meerut, U. P.
A good Auto enthusiast never relies on paper figures to conclude performance of a car.

In your case I am forced to believe you have followed the path of ignorance.
just do not post a comment for the sake of comment. it may sound very amateur and boring.
in gear acceleration of 90hp punto and indica vista is better than swift. it is always better to have in gear acceleration handy than 0-100kmph figure.
Buddy who bothers about in-gear acceleration.If I am moving on a highway and I have to overtake a truck doing 80 kph suddenly then I'll downshift and push and then upshift and enjoy a good acceleration in every gear.Instead of keeping myself in 4th or 5th and accelerate like an ant.
And yes,to conclude that Swift does 0-100 faster under hard acceleration than Indica,Punto etc.I don't need any magazine,only driving is enough to distinguish between their acceleration and any sensible driver in fact even a novice driver can also tell which car has a better overall acceleration.
What you are talking is the highway story where your generally keep in top gear and cover a wide speed band in it,but in traffic conditions the game changes and again Swift comes out as the hero.Its not for that no reason I always appreciate the gear ratio adjustment of MS engineers.They offer the best of all worlds:Performance,FE and pulling.

i can understand what you meant is 50kmph car is having perfect gears and 100bhp one is having worst ..but that is worst example one can give and totally off topic here.
Buddy,there are two type of people one is the person who is unable to understand what we mean and another is the one who does not want to understand,by your above comment it feels like you are very keen to be classified as the second category guy...

Buddy,what I meant from my 50 bhp and 100 bhp comparo is that:
One car is having 50 bhp power but its engineers have got a gearbox which can make the perfect utilisation of the power and requires very less gearshifts to keep then engine in the powerband.While the car with 100 bhp has 'just' got a gearbox but gear ratios are not optimised that nicely,then there are a lot of chances that the car with just 50 bhp will beat the 100 bhp one.

Guys in the Aria on the rpm meter there is green zone from if I recollect marked from 2000 rpm to 3500 rpm is this green zone to let the driver know where the peak torque lies and once you reach this zone you can ufshift and when you fall below this you can downshift ?
Buddy that's the power band of the 2.2 VTT engine of Aria.In this rev range the Aria gives best of its FE,performance and since your turbo is active for whole time,so you need not to change gears in this rev range.
You are absolutely right,if the revs go lower than 2000 then one must downshift and if they go above 3500 then one must upshift.

The approach to my apartment is sort of a dirt road (about 300 m), full of uneven surface, inclines. Last night, when I was coming back home on my Manza (4 adults, 2 kids and some luggage), engaged in 1st gear and let car propel on its own (without using accelerator pedal). I was surprised that the car brought me home through the ups and downs, effortlessly. My wagon r would stall in this condition.
Is it because of high torque of a diesel engine?
Its the low end torque buddy and you have tasted it at its best.
And in case you want to see what is lethargic low end then drive one of the best driver's car in 10 lac price bracket "HONDA CITY I-VTEC"..
 
Joined
Feb 28, 2012
Messages
7,026
Likes
2,846
Location
Mumbai
Thanx vipul and raj again for making things to understand in the most simplest possible way very very fortunate to have you as members and part of
this forum .
 
Joined
Oct 8, 2011
Messages
1,556
Likes
457
Location
Bangalore
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.
I would say this is not a wise way to show off with the petrolhead friends ,as it will very soon be pointed diesels dont rev high & have shorter gearing in comparison to the petrol car(you cant really compare there gearing).

So what if the Petrol car friend said lets see what top speed our cars will do in 2nd & 3rd gear.

Petrols are rev happy(dont have good low end torque) , & diesel are torque rich(dont really do well as revs increase),

So i think the question of Diesel engine vs Petrol should be left out under this thread topic.
 
Thread Starter #38

raj_5004

Honoured Member
Joined
Aug 24, 2009
Messages
5,890
Likes
1,142
Location
Dubai / Mumbai
[*]Mahindra mHawk is having a fantastic torque spread from about 2000-3500 rm and hence this engine offers fantastic responsiveness in mid range.In fact since any car spends most of its life in the mid range only and this car has the best of it,that's the reason mHawk is known for its responsiveness.Am I right Raj?
Good low end torque, perfect gear ratios & nil turbo lag is the reason for mHawk's responsiveness. You are right.
[*]Tata 2.2 VTT DICOR is the only engine to have a VGT here
As said before, even mHawk has a VGT.

Guys in the Aria on the rpm meter there is green zone from if I recollect marked from 2000 rpm to 3500 rpm is this green zone to let the driver know where the peak torque lies and once you reach this zone you can ufshift and when you fall below this you can downshift ?
The green marking is to indicate the 'economy' zone. Stay within that zone & your car will give excellent fuel efficiency.

Is it because of high torque of a diesel engine?
Yes, the superb low end torque, which is inherent in all diesels, right from Ambassador to M&M jeeps to Fortuner!

Buddy who bothers about in-gear acceleration.If I am moving on a highway and I have to overtake a truck doing 80 kph suddenly then I'll downshift and push and then upshift and enjoy a good acceleration in every gear.Instead of keeping myself in 4th or 5th and accelerate like an ant.
If your car has good in gear acceleration, then you wont have to downshift.

Buddy that's the power band of the 2.2 VTT engine of Aria.In this rev range the Aria gives best of its FE,performance and since your turbo is active for whole time,so you need not to change gears in this rev range.
You are absolutely right,if the revs go lower than 2000 then one must downshift and if they go above 3500 then one must upshift.
It is actually the economy zone, not the powerband.

I would say this is not a wise way to show off with the petrolhead friends ,as it will very soon be pointed diesels dont rev high & have shorter gearing in comparison to the petrol car(you cant really compare there gearing).
Ahem, I was just talking about showing off the low end torque... not how superior a diesel is. So there is no petrol v/s diesel debate here.

So i think the question of Diesel engine vs Petrol should be left out under this thread topic.
Sure.
 
Joined
Mar 9, 2012
Messages
51
Likes
1
Location
mumbai
Advantage Diesel.[/B]

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!

yes its true that diesel engines have more torque.mine is indica ev2 lx with crdi engine.in traffics i dont use accelerate paddle at all.just release the clutch slowly and car moves easily wihtout any struggle.the same thing is with our bolero camper lifestyle gold.
 

TSIVipul

Honoured Member
Joined
Aug 6, 2011
Messages
6,203
Likes
4,213
Location
Meerut, U. P.
I would say this is not a wise way to show off with the petrolhead friends ,as it will very soon be pointed diesels dont rev high & have shorter gearing in comparison to the petrol car(you cant really compare there gearing).

So what if the Petrol car friend said lets see what top speed our cars will do in 2nd & 3rd gear.

Petrols are rev happy(dont have good low end torque) , & diesel are torque rich(dont really do well as revs increase),

So i think the question of Diesel engine vs Petrol should be left out under this thread topic.
+100,diesels are torque happy and petrols are rev happy.


Good low end torque, perfect gear ratios & nil turbo lag is the reason for mHawk's responsiveness. You are right.
Are you sure 'NIL' turbo lag,?

As said before, even mHawk has a VGT.
Ah,a mistake of mine.

If your car has good in gear acceleration, then you wont have to downshift.
To get the bursts of power,even you too have to.

It is actually the economy zone, not the powerband.
How it is the economy zone buddy?Let me explain:-
The 2.2 VTT delivers best of its power and torque between 2000-3500 rpm after that the power stars trailing off but still goes strong upto 4500 rpm.
Now if you keep your car in this rev range then you get three advantages:-
1):Great power delivery.
2):Since power delivery will be great,so no need of making upshifts or downshifts.Or say very less usage of clutch and changing of gears.
3):Less usage of clutch and running in same gear for a wide speed band means you get a great FE.
And hence the powerband is always economy zone in the diesel cars.While in petrol ones,its the guzzling zone.

Advantage Diesel.[/B]

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!
Buddy it looks like you went overboard.Since I am yet to drive even a single car till date which climbs uphills without the use of throttle.on the plain surface,it happens..but uphill!!!
 
Thread Starter #41

raj_5004

Honoured Member
Joined
Aug 24, 2009
Messages
5,890
Likes
1,142
Location
Dubai / Mumbai
Are you sure 'NIL' turbo lag,?
The kind of responsiveness it gives, it is almost NIL turbo lag (for a turbo diesel). Yes, if you compare it back to back with a naturally aspirated petrol, you will feel a lag.

To get the bursts of power,even you too have to.
Hmmm, I have rarely felt the need to downshift, even on the highways. To each, its own...

Buddy it looks like you went overboard.Since I am yet to drive even a single car till date which climbs uphills without the use of throttle.on the plain surface,it happens..but uphill!!!
I have never used to throttle to start off in an uphill, in the Scorpio & Innova. By uphill, I mean our ghats... not Ladhakh or Rohtang Pass!
 
Joined
Apr 6, 2012
Messages
876
Likes
187
Location
F Deck
Yes. Today morning I went to Nandi hill. At a steep section, while going up, I stopped and shifted to 1st gear, and started rolling without throttle. 4 adults and 2 children onboard. Believe me, my Manza was pulling up effortlessly. Though very slow, car was moving ahead smoothly.
 

TSIVipul

Honoured Member
Joined
Aug 6, 2011
Messages
6,203
Likes
4,213
Location
Meerut, U. P.
The kind of responsiveness it gives, it is almost NIL turbo lag (for a turbo diesel). Yes, if you compare it back to back with a naturally aspirated petrol, you will feel a lag.
Actually Raj buddy,you are now an expert when it comes to playing with the gearbox and hence any car will have 'NIL' turbo lag for you.As I say "Turbo lag is nothing,its the driver who lags or leads".

Hmmm, I have rarely felt the need to downshift, even on the highways. To each, its own...
Because you do relaxed driving,drive on busy dual carriageways and you will definitely need the feel to make a downshift or two for most of the overtakes.

I have never used to throttle to start off in an uphill, in the Scorpio & Innova. By uphill, I mean our ghats... not Ladhakh or Rohtang Pass!
Well,being true I am quite short of experience when it comes to following this practice,but as many members are coming up with this point,so I can't be that much rigid any more.Especially when I myself haven't tried it on even slight inclines(But,yes,for 'hills' I can bet that this can't work..my driving experience says this).
 
Joined
Apr 6, 2012
Messages
876
Likes
187
Location
F Deck
Having driven petrol cars for quite some time, I always needed throttle to start-off. Even when I drove diesel occassonally, I would drive like a petrol. Only now, when I own a diesel, I started exploring it. And I am amazed by the amount of torque they have.
Slight-off topic, today on my trip to Nandi hill and back, I obtained FE of 20.4 kmpl.
Ascent and descent on 2nd and 3rd gear mostly.
Speed on road, mostly 80-100 kmph.
Total distance: 110km.
 
Joined
Feb 28, 2012
Messages
7,026
Likes
2,846
Location
Mumbai
Having driven petrol cars for quite some time, I always needed throttle to start-off. Even when I drove diesel occassonally, I would drive like a petrol. Only now, when I own a diesel, I started exploring it. And I am amazed by the amount of torque they have.
Slight-off topic, today on my trip to Nandi hill and back, I obtained FE of 20.4 kmpl.
Ascent and descent on 2nd and 3rd gear mostly.
Speed on road, mostly 80-100 kmph.
Total distance: 110km.
Nozzlering that's impressive mileage buddy [clap]
 

Top Bottom