[Apex1815]

First of all I would like to express my sincere gratitude to Team-Bhp for approving my membership request. Last week I got my membership and this is my first post on Team-Bhp.

A brief introduction about myself: I work with an Automobile OEM (Earthmoving Machinery manufacturer) from almost a decade and my area of expertise is Vehicle Homologation, Regulations & Compliance. I often come across the queries related to Cars and bikes from my friends/ relatives and I try to answer them in a very layman language so that it is easier for them to understand the technical aspects of automobiles. At least, at home I want to avoid the language of Technical Standards & Regulations for the vehicles.

Recently (from the past Two to Three years), the Indian car market has seen a lot of hype about Turbo Charged Petrol Engine cars over their naturally aspirated counter parts. Ever since the Turbo-Petrol Engines have kicked in the Indian market, it has gained attention of a lot of potential car buyers (especially post launch of Hyundai Venue, i20 & KIA Sonet). Many car buyers aspire their set of wheels to be equipped with Turbo-Petrol Engine (because that has become fashion), without even knowing their driving requirements and blindly follow the mob. Many of the car buyers who end up following the league of Turbo-Petrol often regret later about lesser fuel efficiency of a Turbo-Petrol Engine car.
While few people use their time and resources diligently to select and buy the right car as per their requirement, many buyers just follow that fashion league during car purchase and prefer Turbocharged Petrol Engine, Large TV type looking Touch screen on the Dashboard, Sunroof, Engine On/Off Push button etc.

I came across a lot of dilemma among few friends on Turbo waali Petrol gaadi and Naturally Aspirated Engine and thought of simplifying the same by quoting the example below so that even a person who just uses the car for simple office going can understand his requirement of the right engine.

Example:
Hyundai uses the 1.2 Litre Kappa Petrol Engine (Naturally Aspirated) in Grand i10. The same 1.2 Litre Naturally Aspirated Engine is also used in i20 & Venue.
Now, it is already known to the mankind since the inception of this planet that i20 and Venue are heavier than the Grand i10 therefore 1.2 litre petrol (which is used in Grand i10) does not perform in the same manner as it does on Grand i10. After reading such a statement, a not so enthusiast buyer will shift towards a Turbo Petrol Engine so as to maintain some status among his neighbours and peer group. <You never know when the uncle ji in neighbourhood will question the capability of a naturally aspirated 1.2 litre i20/Venue – Beta Turbo waali Venue nahi dekhi thi kya who jyada power nikalti hai ?”
So keeping all such peer pressures apart, let us try to understand this in terms of Power to weight figures below for a naturally aspirated engine (1.2 Litre Kappa Petrol of Hyundai) and decide whether it is a suitable engine for your next purchase.

The weight of the cars considered below is the Average of Kerb weight available on internet as the actual weight of the variants is not available in the company’s Brochure.



A simple look at the figures above indicate that i20 produces 10.5% lesser power and Venue produces 15.4% lesser power than Grand i10.
Further a look on the Kerb weight figures of the car will give some more insights about the Feel factor of driving these cars:



Considering the Kerb weight differences among Grand i10, i20 & Venue following inferences are drawn to understand the Driving feel factor of 1.2 Litre Kappa Petrol on i20 and Venue:
1) i20 (solo) driving feel factor = Driver + Two slim people on board on Grand i10
2) Venue (solo) driving feel factor = Driver + 3 slim people on board in Grand i10
If you drive a Hyundai Venue or i20 with 1.2 Litre naturally aspirated Petrol Engine you will not find a huge difference as compared to the Grand i10.

Verdict:

Potential candidates for naturally aspirated Engine:
-A calm driver, -Majority (say 90%) of your driving miles are solo (or with small family i.e spouse and a kid)
-Drives mostly in city areas -Rarely go to long drives (like once or twice a year)

Turbo Charged Engine potential candidates:
-A driver who always want to overtake the vehicles ahead
-Majority (say 90%) of your driving miles are with fully occupied vehicle
-Frequently goes to long drives

With more urbanized lives and nuclear families, most of the potential buyers will actually need the Naturally aspirated Engine.

Most of the times the Test drive of a car is for a very limited Kms like 2~3 Kms and it is not possible for everyone to judge the dynamics of the car with such a small test drive. So with this type of small brain storming one can understand his requirement better.

Thank you for reading my post.

[GTO]

Originally Posted by Apex1815

So keeping all such peer pressures apart, let us try to understand this in terms of Power to weight figures below for a naturally aspirated engine (1.2 Litre Kappa Petrol of Hyundai) and decide whether it is a suitable engine for your next purchase.

I appreciate your analysis, but disagree with the entire premise of your post. You cannot choose which engine is better via an excel sheet.

Case in point = Hyundai. Their 1.0L turbo-petrol is superior in almost every way to the old & now outdated 1.2L NA motor. It has decent driveability, is refined enough, revs surprisingly well for a Hyundai petrol and runs like a horse on the open road. With a light foot, the fuel efficiency is acceptable.

It's no "fashion league". The direct-injection turbo-petrols offer 50 - 100% more torque, a punchier mid-range, faster performance and don't need to be revved to 5000 - 6000 rpm to extract power. Unlike NA petrols, they are alive even at 2000 rpm.

The main downsides = higher price than the 1.2 NA, and the drop in FE if you drive hard (as is the case with all turbo-petrols). In every other area, the turbo petrol is the superior and 99% of Indians don't drive hard.

If you have budget constraints, fine, go for the 1.2 NA and you'll be okay. But if you don't have budgetary constraints and still buy the 1.2 NA, it's like getting an iPhone 4 today. You got to move with the times.

[Kosfactor]

In normal city traffic an i20 works very well with its 1.2 NA engine, it has good driveability, most refined cabin of them all and overall a relaxing place to be.

Once you are on the open road, any need for swift progress - like overtaking will need some planning, the engine has to be nicely wound up to perform. A turbo on the other hand produces more power in the cruising RPM range,so just push the pedal and off it goes - effortlessly.

[arindambasu13]

Originally Posted by GTO

The direct-injection turbo-petrols ....don't need to be revved to 5000 - 6000 rpm to extract power. Unlike NA petrols, they are alive even at 2000 rpm.

While I understand that turbo petrols are the future, and will only get better and more efficient at delivering power and reliability going forward, I would differ with you on the generality of this statement. For instance, the City iVTEC that I drive daily is very much alive and kicking at 2000 RPM onwards. Yes, the nature of the engine may be different, i.e. more linear build up of power and not a sudden surge at the turbo-boost RPM, but this is one NA petrol which is responsive even from 1500 RPM onwards. The good old Honda definitely does not need to be revved till 5000 RPM to get going and feel alive In fact, with my not too aggressive driving style, I have enough power at my disposal between 2000-3500 RPM in most daily use scenarios.

Agree though that the current 1.2 petrols (Hyundai, Suzuki etc.) behave differently and respond better at substantially higher RPMs. Also agree that in a comparison of 1.2 NA and 1 liter turbo as in the instant case, the turbo would probably perform much better in most situations.

[androdev]

Don't underestimate that 0.01% of the situations where you need instant power. This is not a country of curtious road users who will allow you plan your overtaking maneuver as per your power to weight ratio.

[Jeroen]

I appreciate that some people might be impressed by having a turbo, but that will pass.

In the western world, nobody, expect some petrol head nerds, would know whether their car engine has or doesn’t have a turbo. You would be hard pressed to find out too. Unless you know what to look for under the hood.

I agree with GTO’s comment. The problem is that these sort of analysis get lost in some very simple commonalities of NA versus turbo engines. These days a very moot comparison in my opinion. Because in practice so many other variables come into play.

I really don’t see the point of comparing say a 2.0 l NA engine to a 2.0 l turbo engine. It’s like chalk and cheese. They both serve a different purpose.

So in the end it is the combination of car, engine, drive train, transmission and a bunch of other variables that gives you a certain performance.

We have not seen cars being badges as “turbo” for decades. I remember it very well, because I am a very old git. I remember the first Saab turbo. It was specifically marketed as Turbo and wore a badge that saidTurbo at the back. Did nothing for the image of the car as such. Saab owners are only marginally less boring than sheep. Be it NA or turbo.

We had the Renault 5 Turbo. And a few others. In those days the difference between the turbo and non turbo version would be quite spectacular. They were also a pain to drive in normal commuting traffic. But some sad souls decided the turbo badge looked cool. Hence, these cars were primarily sought after by men who thought it would make them more attractive to girls. A sad mistake, because most women have very different interests and more pressing matters to attend to then turbo’s.

I haven’t done the math, but I would say that in the west probably 90% of ICE cars sold are turbo these days. Only some, usually the lowest model variant might be NA. Nobody cares, nobody notices to my earlier point. Even in car brochures these days it might be hard to find what kind of engine is fitted.

NA or turbo, for all intents and purpose is a non issue for most car owners. It’s a topic discussed on car forums. Technically speaking I can go on about turbos or NA engines for that matter, for hours, but my wife would find it all very boring.

I would be very interesting to hear a bit more about your job with respect to regulation compliance and so on.

Jeroen

[asit.kulkarni93]

When I drove the boosterjet equipped Baleno back to back with the k12 Baleno, I realised why these small turbocharged engines are amazing. The k12 had an amazing low end performance but mid range was flat. Unnecessary revving to the top end yielded nothing. The boosterjet had a manageable low end and a punchy mid range which made driving within the city and on highways very easy. A fully loaded Baleno boosterjet vs k12 will make one realise why turbo makes a very strong case. The first time my friend drove the boosterjet Baleno, he switched from the Delta MT to Baleno. He is not an enthusiast but loved the availability of torque available lower down.

Point being we can do comparison based on spec sheets but the real world feel of driving a well tuned turbo charged engine vs NA engine especially of smaller capacity is huge. Just driving the Polo 1.6 MPI vs 1.0L TSi can show you the difference.

[Kosfactor]

Originally Posted by arindambasu13

Agree though that the current 1.2 petrols (Hyundai, Suzuki etc.) behave differently and respond better at substantially higher RPMs.

OT : VTEC is notorious for its poor low end response. As someone who used to switch among these vehicles of Hyundai and Honda, VVT vs iVTEC, I`ll take a Hyundai any day. Their petrol has better drivability, be it city or highway makes for a much effortless driving experience.

Brio Vs i20 - i20.
City Vs Verna - Verna.

Also, Suzuki, Honda, Hyundai all uses some sort of Variable valve tech.

[Raghu M]

Great thread, but the choice of an NA engine vs. Turbo is also because of the range a company offers. Take for example Hyundai. They do not offer a NA engine on their top models. It is only turbo engines that are on offer. How can a customer make a choice in such situations? I don't think the average Indian customer knows the difference between a normal and turbo engine. If he/she wants a high end model, they have to go for the turbo, there is not much choice there. Speak to Hyundai and tell them you need a NA engine but also with sunroof, 6 airbags, traction control and other features, they will draw a blank face. There is simply no choice available to a customer if he/she wants to opt only for NA engines, they need to go down the model list and pick a bare bones one.

[arindambasu13]

Originally Posted by Kosfactor

OT : VTEC is notorious for its poor low end response. As someone who used to switch among these vehicles of Hyundai and Honda, VVT vs iVTEC, I`ll take a Hyundai any day. Their petrol has better drivability, be it city or highway makes for a much effortless driving experience.

Really? I have not come across a single instance of poor low end response in the 1.5 iVTEC across close to 16,000 kms of driving on an every day basis in the past couple of years. So I am really not sure what you mean when you say "low end". If is its sub 1200-1300 RPM then yes, response is nothing to write home about, but that would presumably be the case in any engine in this segment. But anything above that, absolutely no question of poor response. In fact, the City's sharpness of throttle response is among the best out there. Above 2000 RPM, as I had pointed mentioned earlier, the power flow is solid and smoothly progressive.

As for your comparison - I have limited experience with Hyundais (except maybe a few drives on friends' Verna and Creta, totalling to possibly 300-400 odd kms), since Hyundai cars have not appealed to me in any way (mechanically or cosmetically) at any point in time. I did for sake of good order test drive the Verna when I picked up my City in 2019, but there was no comparison in terms of driving pleasure as far as I was concerned.

I have also owned a Brio for several years, and yes, the 1.2 iVTEC on that one is certainly much slower to respond at sub 2000 RPMs. Which is why my post about responsiveness was very specifically about the larger 1.5 iVTEC engine.

[landcruiser123]

This is exactly the kind of thing my manager terms as "analysis-paralysis." Everybody wants to keep up with the Joneses, so they'll buy whatever car their wallet permits.

If we lived a need based life, we'd have 3 pairs of clothes, live in small houses, take buses to work, drive small hatchbacks on weekends etc.

[pavi]

I own a 4th generation Honda City ivtec MT and a Skoda Rapid TSI MT. We can consider these engines best in their segments, hope you all agree with me on this. City has covered 1 lakh kms till now and Rapid is at 3000 kms.

Pros of a turbo engine.
1. A turbo engine needs much lesser time to complete an overtake at the right rpm. That right rpm is actually very low in a turbo engine compared to a NA engine. Higher torque in play here.
2. A turbo engine can keep the average speed of your journey high with out much work required from the driver end.
3. The availability of torque at lower rpm itself help you climb an incline very easily. Keep in first gear and leave your clutch, Rapid will easily climb most gradiants with out any accelerator input. Again torque in play here.


Cons of a turbo engine
1. Accelerator modulation is not smooth especially in long corners.
2. The usual culprit, turbo lag.
3. Rev matching downshifts are not that much fun as the revs need not be kept high.
4. Also accelerator input and corresponding rpm rise is not linear in a turbo.

If you ask me, which one I prefer, it's seasonal . For high revving fun and rev matching downshifts I would prefer a NA engine. For easy driving, I would prefer a turbo. You can complain NA engine's not so good mid range, and turbo engine's limited rpm limit. But at the same time, you can really enjoy the mid range punch/fun in a turbo engine and high revving fun in a NA engine. So understand the behavior of each of these engines and enjoy the positives.

Note: all the above observations are based on my experience with ivtec and TSI engines only.

[Rocketscience]

I don't agree with this post at all, i have had first hand experience with Kappa 1 engine in my i20, Kappa 2 engine in my brother's i10 and Kappa 2 engine in my cousin's i20, all for considerable long distances.

This is by far the lamest engine i have ever driven with hardly any redeeming points when it comes to its application in heavier cars (i20s in my experience), also don't be mistaken that the power drop in proportional to the additional weight, it drops exponentially (i'am not sure of the correct mathematical term), and the difference in i10 and i20 is staggering when it comes to performance, in i20, it is choked, it feels as if you are driving a car with handbrake on, it has no power anywhere in the revv range, it has average driveability, but for anything more you need to revv it like crazy because of poor torque thanks to no turbo, doing it makes it extremely fuel inefficient, but get this, you need to revv it like that to get a fair bit of performance to do your regular manoeuvres too.

I have not driven any other car which feels as lethargic, since it has poor torque and high weight, Hyundai has to gear it short and even when cruising at 100km/h, you see the revvs at 3100 rpm, which is not good at all for the fuel economy.

In regular city riding too, you need to revv it to atleast 3k to get some go, it gets much worse as you increase the weight further and add more passengers and luggage, i took this car to my school farewell and with 5 of us in the car, it struggled to climb flyovers, it was my first experience like this, this was with full throttle mind you, which is pointless in case of this engine.

In my hands it returned 8km/l (i didn't drive it fast because after a while i had given up on it), in my dad's hand who is somewhat of a sedate driver it returned 9km/l, all this for a car which is downright dangerous if you want to overtake and i have had my share of embarrassing moments where i honked to get the other car to move/not enter my lane and then buried my feet to accelerate and this thing won't move.

Torque is the key and in my experience of driving turbo diesels for the last decade, i'am never moving back to naturally aspirated engines, in fun to drive cars like Swift and even the older gen i10, things went south quickly as you load more passengers, as compared to you doing the same thing with turbo petrols/diesels, the answer is simple, more torque.

What's even better is turbo diesels, they will offer you about as much power, more torque, and substantially more fuel economy, they are not much more expensive than turbo petrols too, ticks all the correct boxes.

[GeeTee TSI]

I think the matter is more about progressing with the times in the Indian context, specifically in sub D segment cars. These segments weren't always contemporary to global offerings and for years we had only 2 digit horsepower offerings (with suitably low torque figures) and I am referring to petrols here.

Thankfully, we now get a bump in horsepower and torque thanks to turbo charging (we never really got bigger engine options in NA either) in these segments.

On a lighter note, if this is perceived as a fashion statement; then we're probably on the cusp of the 80's turbo era of mature markets

[amitayu]

As long as we have the sub 4mtr/1200cc excise regulation, the only route for more power out of our affordable hatches seems to be going turbo.

I say seems, because the Ford Dragon series seemed like a revelation to me (and I was literally 'sold', buying a Freestyle) because it is both hassle-free yet powerful. If we can have better NA engines with more power, we do not necessarily need turbo petrol engines.

However, driving in city traffic, I feel the torque and at what rev band is a more critical parameter, both for ease of driving and mileage/performance of the car.

We often get too obsessed with top BHP figures and how much the engine revs.