“The Tata Sierra’s platform is also all-wheel drive capable, and it can work on multi-energy” says Mohan Savarkar, Chief Product Officer and VP

Following the highly anticipated unveiling of the new Tata Sierra, we take a closer look at the crucial engineering decisions that brought this legendary nameplate back to life. Ed Sirish speaks with Mohan Savarkar, Chief Product Officer & VP, Tata Motors, to discuss the brand-new, multi-energy platform underpinning the car, the development of the company’s first new petrol engine in years, and the intense focus on manufacturing quality to position the Sierra as a premium mid-size SUV.

Sirish: Mohan, the Sierra concept – there must have been a lot of learning from it, a lot of inputs from various stakeholders that finally went into the production form. What were the main changes that came through in the production vehicle?

Mohan: First of all, welcome, Sirish. Nice meeting you once again. So, when we were doing the Sierra programme, this is, of course, on the back of all the earlier programmes that we have done, and inside we have been doing a lot of improvement in terms of how we should get new cars to the market. So, you would have seen with this car that we have attempted to change the way we do things in almost every aspect, so there is a new powertrain, there's a new platform, there’s a new manufacturing setup. In the vendors also, we have tried to attempt a very different way of interacting with everyone. All this is based on all the learnings that we have had so far, and it has worked for us.

Sirish: The platform, what platform is this? Is this derived from an existing Tata Motors portfolio platform? Can you tell us about it?

Mohan: So, this is a brand new platform. So, you're familiar with our set of cars.

Sirish: Yes.

Mohan: So, we have the Atlas and we have the Omega, and there's space in between, so this platform is supposed to be for that space. It's also all-wheel drive capable, and it can work on multi-energy: ICE with NA or GDI or diesel or CNG, or what have you. Everything can be accommodated in this. For the EV, we will use a different platform underneath.

Sirish: What do you mean by all-wheel drive capability? The Sierra, I'm assuming, is front-wheel drive only?

Mohan: Yes.

Sirish: So, you mean what do you mean by all-wheel drive capable? That there will be a 4x4 version later on?

Mohan: Not 4x4, all-wheel drive, okay? Just to draw the distinction. So, which means that we are not looking at boulder crossing or something like that, but we are definitely looking at a car that is capable of taking all terrains, all surfaces, and, let’s say, low mU on one tyre, high mU on another. All that kind of technical stuff can be done with this.

Sirish: So, this platform is capable of it, and the Sierra will come with an all-wheel drive version in the future?

Mohan: We hope to. It's something you'll need to wait for.

Sirish: This has got a torsion beam rear suspension as of now?

Mohan: So, this has got a twist beam at the rear end. So, when we go to all-wheel drive, it will have to have independent suspensions.

Sirish: So, it is already there in the architecture?

Mohan: It is capable of doing that.

Sirish: The new petrol engine, that is the big talking point. That's your first new engine in a very long time, if I'm not mistaken. What went through the development of this? We first saw it five years ago at the Auto Expo.

Mohan: Not five, three.

Sirish: Three years ago, so it must have gone through a lot of iterations. What are the significant takeaways from this programme?

Mohan: Yes. So, we were very fortunate that we got an opportunity to do a new gasoline engine in 2025. You know, most other people have different plans. So, when we did this, we were fortunate to make sure that we could pick things that have gone well in many engines around the world. And then we put all of that into this. So, including low friction ring packs, the 350 bar injection pressure, the deep skirt, and, you know, so many other things that have worked around the world, so we could capture and put it all here.

Sirish: The key focus on this engine has been what: performance, refinement, fuel economy?

Mohan: All three. So, first of all, it has to be refined, okay? It's something that, you know, is the need for a car like this. It needs to be refined. Then it needs to provide enough power and torque for a car of this size. The fuel efficiency, it will, of course, have to meet the CAFE norms that are coming up, and it needs to provide, let's say, at least a competitive kind of fuel efficiency in its peers.

Sirish: In terms of the transmissions, will this have a twin clutch automatic transmission?

Mohan: No, the GDI comes with an automatic transmission with a torque converter from Aisin, which is a six-speed transmission.

Sirish: Okay. And then the NA version will come with what: CVT or DCT?

Mohan: The NA comes with a DCT.

Sirish: Okay, and the diesel. Now this is an evolution of the engine you already have. You've increased the torque a little bit, and what kind of transmission will that come in?

Mohan: That's a slightly different way of putting it, but we have kind of improved the combustion. We've improved the brake thermal efficiency, so it's a next-generation engine.

Sirish: Of the diesel?

Mohan: Of the diesel. This has already got 280Nm and headroom for more. And with the 280 Newton metres, we could put the Aisin six-speed automatic transmission. On the manual side, though, we will stay with the 260Nm existing transmissions.

Sirish: So, the manual will have the six-speed transmission?

Mohan: Six-speed and 260Nm.

Sirish: In terms of the size of the engine bay, you could not package the two-litre diesel engine into this that you already have in the portfolio?

Mohan: Different topic once again. So, it depends on the size of the car, the weight of the car. Generally, you don't need a two-litre engine unless the car weighs above a certain thing. The two-litre engine also brings in its own additional weight, which is maybe another 78-80 kilos. So, net of it all, for this size of car, 1.5 is more than enough. There is a lot of capability in the 1.5.

Sirish: In terms of quality control, what steps have you taken to ensure the Sierra meets class benchmarks?

Mohan: Yes. So, the whole NPA process has been fine-tuned. And (by) the way – if you see our car – the kind of gaps that we have been able to achieve with this is very different from anything that you would have seen in all our earlier cars. So, we have changed the manufacturing process, and the die has been machined multiple times, okay? First time, check the gaps. If gaps are not to our liking, machine it once again, and if required, third time, until you get this consistent gap. And also, it has helped quite a bit. We have used laser brazing for the roof, laser stitching for all the closures. So, that gives a lot of strength to all the closures and a very good torsional stiffness also. So, all this brings this body very, very stable.

Sirish: And this is also built at your new facility?

Mohan: Yes.

Sirish: So, in terms of the product positioning, how is this going to set like a new benchmark for Tata Motors?

Mohan: So, the way we see it is that segment-wise, it would be C-segment, which is, let's say, a 4.3-metre car in India. However, we are trying to create a new category called premium mid-size SUV. And you would also know that around the world you would see cars which are like base, mid, premium, and luxury. So, we are trying to go into the premium segment with this car.

Sirish: But there must have been a lot of challenges or conflicts between the design teams, the styling teams, and the engineering teams. What were the key challenges and how did you overcome them?

Mohan: Yes, for example, if you see the side of the car, there's no way seal visible. Now, how to do that on the shop floor is a very different thing than doing it in the studio. Then, if you see the side of the car, the glazing on the side of the car, normally you will see steps wherever there is a glass guide. Yes, so all that is also very flushed in this car. So, those are things that we have managed very well. Then you will see all the lights are very, very slim. So, to get these kinds of lights made, and let’s say the 1.8-metre long, you know, DRL in the front, or the 1.6-metre long tail lamp, and the headlamps – you know, if you have seen it’s only 17mm aperture. Just so small, you can barely make out it is a headlamp unless you know where to look in the car. So, all these have been very tough challenges to rise up to.

Sirish: Finally, what aspect of the Sierra are you most proud about?

Mohan: The whole ambience in the car. I mean, it's come out so well with all the materials, touch, feel, the spaciousness, the glass house. It's come out very well.

Sirish: All the best, Mohan, and look forward to seeing the car and finally driving it next week.

Mohan: Yes, please. Most welcome, Sirish.

Sirish: Thank you.