[chautob0t]

I can't vote yet due to new member restrictions (but have been lurking for a decade without signing up, so not a 'new' member).

I vote YES with my anecdotal evidence as I have never owned a turbo petrol car.

From the experience of test drives of Ecosport 1.5L NA (twice) vs Venue and Sonet with their turbos, I will definitely go for NA in Indian city driving conditions.

The Sonet was absolutely dead after every speed breaker, no throttle response at crawling speeds and post speed-breaker/pot-holes. Venue seemed a tiny bit better but the turbo lag is very evident. While the mid-range felt very satisfying in an open stretch of road but that open stretch is rarely available in metro during office hours. (I have lived in Delhi, Mumbai, Bangalore - same experience everywhere)

While I agree that highway speeds at lower RPMs will be relaxed in these petrol turbos but in my household's usage, city dynamics take the highest priority hence, I'd prefer a NA petrol any day.

[Reinhard]

Well for me its always diesels. But - In the daily driver segments - I'd still pick up an NA petrol over small turbo counterparts.

In fact - in the <20 Lakh region, I'll pick the Maruti K12 - which means those are the only petrol cars that I'll pick at all. For anything else <20 Lakhs I'll go straight for a diesel really. Or an EV for that matter. Somehow tiny turbo petrols are not impressing me at all. They are poor on NVH, they run very hot, they don't bring any cost savings vis-a-vis diesel, have a lag, and have poor fuel efficiency too!

Somehow for me - petrols always NA and diesels always turbo! Its kind of hard-set in the mind. Don't think it will ever change.

[Jaggu]

I still have one in my Grand Vitara, a naturally aspirated 2.4 liter petrol and love it to the bits . It loves to gulp petrol but the overall fun factor of that engine is the best part of the vehicle.

The sad fact is more than any other reasons, it is the pollution and environment norms that are forcing manufacturers to move to the forced induction world. Some of them are darn good (I agree), but nothing like a big fat naturally aspirated petrol engine for silly grin to your face.

[clevermax]

Originally Posted by jacob.thomas

It seems to be counter intuitive that turbo petrols are known to give pitiful efficiency if driven with anything but a feather light foot. Just wanted to know if I am missing something.

You're right. One should not expect fuel efficiency at all, if he/she is going to make use of that turbo in a turbo-petrol. Even cars like Baleno RS will give you 7 or 8 kmpl if you decide to have a fun drive with it.

[Akash.D]

There is a thing called Turbo Lag. Technically, it is the time required for the turbo to actuate, i.e. the engine rpm reaches the point where the exhaust gases can actually get the turbine to compress the intake air. Until that point is reached, the turbo is non-functional and when that is achieved you get the kick-in-the pants feel. So, to enjoy the turbo engine you have to keep the engine running above a certain rpm. Suppose, you are in a traffic congested road and when shifting to lower gear the engine rpm rises there will be a power surge due to activation of the turbo. This makes a turbo engine difficult to handle in stop and go traffic. A sufficiently sized NA engine, on the other hand, has a linear power vs rpm curve and everything is predictable. Not that I don't love turbo charged petrol engines, I also not hate the NA ones. Both are and will be required for different case scenarios.

Turbo charged engines helps in getting same power & torque as a larger capacity NA engine. It is also necessary in high altitude areas where the air pressure is lower comparatively. But to say that NA petrol engines have become obsolete is still farfetched an I believe that there is a lot left in the NA petrol engine technology to explore.

[Nav-i-gator]

I don't see why a good NA petrol should fade away (4-pot ones I am taking about. NA 3 cylinder ones should definitely go away). Absolute refinement of a K12, K15, Hyundai or Honda NA engines is surreal. I drive a rather poorly maintain Chevy Beat 2010 model. While the motor is not something to talk about in terms of power as well as "revvability", the idling motor is still hardly perceptible.

In our city traffic, NA engine is better than the turbo one as turbo engines can get jerky with constant throttle inputs (and subsequent turbo push), NA ones are butter smooth. Most of the NA engines have good low end torque as well (Dragon 1.5, Verna 1.5, K15) so filling traffic gaps is easier as well.

On the highway, one can compensate for the lack of mid range push to the seat feeling of turbo engines with just revving the nuts out of NA engines.

Not to mention the idling rule we have to follow while starting and stopping.

I will pick a proper 4 pot NA engine just for the brilliant refinement and silent, non-vibrating cabin itself. Having said that, turbo-petrol engines with proper 4 pots would just be the best of both worlds I think.

[landcruiser123]

I think the real problem is the tax structure which is the reason why most brands dish out lame NA petrol engines in India. In the USA, purists are getting their hands on the V8s and V6s which are also under the verge of extinction. Given the factors of cost and reliability, I’d pick a diesel over a turbo petrol in India.

While EVs are going to dominate 8-10 years from now, I’m willing to bet there’ll be quite a few owners of Turbo petrol engines who won’t be happy with their service bills. (Turbo diesels are more robust)

TBHP won’t see too many cars like paragssachania’s ageless WagonR.

[tharian]

Honestly, although I chose NA, I like driving both turbo and NA cars.

My only issue with a turbo engine, especially a diesel, is the narrow power band on highways. With a turbo petrol, I have driven very few of them and of that, it was the 1.4 TJet that I had a chance to drive on the highway for a while. Compared to the NA, it is just that pick up and mid range that is there to be enjoyed. On a NA, it is much more fun to take it to the limit and hear it sing unlike a turbo.

There is a first gen Swift petrol which I hate driving in the city for some reason, but when I take it out on the highway once a while, it is fun to listen to the engine rev and pick up speed without flattening out before you know it.
With my Aspire diesel, everything is done and dusted quickly and you are already at high revs which doesn't sound good unlike a NA. Maybe when I get to drive a turbo petrol, it maybe different, but with most of them being 3 cylinder turbo petrol's, I am guessing the higher revs won't be that smooth on NVH either.

[NFS2024]

I voted No.

Between the Turbo Diesels, NA and Turbo Petrol, I would pick up the Turbo Petrol.

It has become mainstream, can power small to bigger cars. Power comes in smooth and effortlessly. The engine is revv happy, mid range and top end is fantastic, there is very little noise and if driven sedately, gives decent FE. You don't have to drive the car at high rpm always to extract power.

And when mated to good chassis, gear box, it becomes real fun to drive.

Having driven turbo diesel for 2 lac Kms over the last 12 years and in between driving all sorts of cars, I have come to appreciate the Turbo Petrols even more now.

[sou_3749]

Voted No.
I was never a fan of NA engines. You need to have a big NA engine to extract some fun which is not economical in most scenarios. Or you make the car so light that the 1.2 K-series will beat most cars. That's the reason I became a fan of turbo diesels which is a balance between fun and efficiency.

But there are certain issues with turbo engines.

1. Lower down the rev range, the turbo engine becomes a NA engine. So in order to extract power you need to raise the RPM in that small engine. The saving grace for diesel that it's more fuel efficient by nature which offsets the high revs.

2. You need to change gears frequently in city conditions in order to be in correct power band. More gear changes equals less FE. This is true for both petrol and diesel. Both petrol and diesel turbo engines when mated with manual transmission is bound to be jerky for most as sudden surge of power needs your left foot to be more precise while working on the clutch pedal.

3. NHV will be a little more as there are some extra components in the engine bay doing the job of missing cylinder or capacity plus the natural imbalance in 3 cylinder engine. It's easier/cost effective to put a bigger turbo with a 3 cylinder and extract similar performance than putting a smaller turbo with a 4 cylinder. That's the reason we see mostly 1.0 L turbos rather than 1.2/1.5 L.

The solution - petrol turbo with auto gearbox. This takes out the struggle in lower down the rev range. You drive sane, it's bound to give you better driving pleasure with better FE vis-a-vis NA petrol. You want to drive the nuts out of that engine, there are race tracks out there. Then don't expect good FE whether turbo or NA. Once you drive a turbo, there is no coming back to NA.

There is no way the best NA petrol (Vtec 1.5) beats the best small turbo (1.2/1.0 TSI).

[vshankarhere]

While I do agree turbo petrol are catching up and are becoming the buzzword post BS6 implementation, I seriously don't think they trump NA engines tooth and nail. I drive a NA petrol now and I find it competent enough and some more fun. NA engines are there to stay.

[srini1785]

This thread reminded me of the discussions here :

https://www.team-bhp.com/forum/india...ge-market.html (Maruti finds cars with small turbo-petrol engines a challenge to market)

To quote MSIL :

Speaking to Autocar India, CV Raman, senior executive director, Maruti Suzuki, spoke of the carmaker’s challenge of marketing small turbo-petrol engines in India. “What we understood from the customer is that he perceives a 1.0-litre engine as a 1.0-litre engine, and he perceives a 1.5-litre engine as a 1.5-litre engine, that is, as a bigger engine. He is not so clued onto whether it is a turbo-petrol or not. Of course, there are connoisseurs and there are enthusiasts out there, but there is a bigger audience which looks at the size of the engine as 1.0-litre, 1.2-litre or 1.5-litre. So, if a 1.0-litre turbocharged is also there, he will consider it to be a smaller engine and not having the necessary torque or the power to propel a bigger vehicle. So he will feel like that. So our analysis shows that he would much rather prefer a 1.5-litre compared to a 1.0-litre.”

Half of the votes have concluded similar to the last sentence :

"So our analysis shows that he would much rather prefer a 1.5-litre compared to a 1.0-litre."

Personally i have driven a Turbo only once. A VW Polo TSI1.0 and man what a difference. I could not believe that my K10 and this TSI had the same base 1L engine config. The 1.0 TSI was a torque monster. That said, it was a highway drive between Bangalore and Chennai and there is no way a NA engine beats a Turbo of similar capacity on open roads. On city roads with a manual gearbox, turbos are no different to a NA engine.

[Jeroen]

Originally Posted by jacob.thomas

. But in the real world are we seeing any gains (environmentally) by going the forced induction route?

Going a bit of topic, but the short answer is yes. And not just at low RPMs.

Adding a turbo to an engine allows you to extract more power out of the same size/weight engine. Or conversely, you can have a smaller, lighter engine produce the same output.

Small and light is always good on any car. Less weight to carry around makes a huge difference in power required and thus emission. It also allows for better handling and more streamlined design.

The actual effects and how a turbo design makes for a more environmentally friendly package is quite complex. The individuals effects of various aspects of turbo charging are difficult to quantify in simple measures, but the overall nett results appears to be positive.

If you feel up to it, the introduction makes for a good reading, though pretty technical.

https://www.sciencedirect.com/scienc...10016817300960

[carthick1000]

Voted yes.

I drive an electric car. If I ever were to buy again a fossil fuel car, it would definitely be an MX-5 with a naturally Aspirated engine that too from Mazda's Skyactiv-G or Skyactiv-X lineup.

Originally Posted by GTO

Hell, their last big "technological change" was MPFI & catalytic converters back in the 1990s.

Well, not true.

Take a look at SPCCI (SPark Controlled Compression Ignition)technology of Mazda's Skyactiv-X engines.

https://www.youtube.com/watch?v=aAjohUQwSXo

Engineering explained delves a bit deeper into the technicalities of the engine:

https://www.youtube.com/watch?v=yNSxow3W7ek

[John P Daniel]

I would pick a NA petrol anyday as I love the instant throttle response. Sure, the turbo petrols may deliver more torque and power in it's optimum rpm range but the response feel of a NA throughout the rev range is what I love. Unfortunately, there is not much cars today that are properly NA.
The McLaren F1 is still a NA car built in the 90s but it can still hold it's ground to modern equivalents. That is the capability of a Naturally Aspirated petrol engine.