Non-tech: Regarding petrol NA vs Turbo engines

I owned a Maruti Celerio VXI AGS MY2020 for almost 5 years. And recently switched to a Tata Nexon Creative S+AMT. This post will talk about the difference in engines on both these cars and the effect it has on driving dynamics and mileage.

First of all Maruti has 1L NA engine which is tuned frugally and returns very good mileage. I have seen it return 15kmpl in city with AC ON. And on highways it can hit 18-19kmpl fully loaded and with AC ON.

Although this car is an economy hatchback and is not really tuned to cruising. That's why at 80-90kmph, engine is around 2800-3000 RPM and good mileage is observed around 80kmpl, and after that it drops. Plus the 1L 3-Cyl engine means not enough torque and so jerky driving in low speeds and ghats. Still for the low price even with AMT gearbox, very good value for money.

Moving on to Nexon, the engine is 1.2L turbo-petrol. The turbo really spins at around 2000RPM and provides max boost. Although the engine maps provided are such that there's enough power at low end also. There are 3 modes provided eco, city and sport. They primarily change AMT gear shifting points along with engine power characteristics. So in economy mode power is less and AMT shifts to higher gears quickly. So this mode is very good for sedate driving. City mode increases power and makes gear shifts longer, and is good for usual city driving with enough power. Sport mode improves this further and usually tanks the economy except for a band of speeds where turbo provides maximum boost and runs the engine leaner and thus increasing mileage.

Looking at the turbo-effect closer, what happens is below 1500-1800 RPM the engine works similar to a NA engine with turbo not adding a lot of boost. Around 1800 RPM turbo spools high enough to improve boost and providing more power and mileage. So if we are able to cruise between 2000-2500 RPM we get optimal conditions with maximum mileage. Cruising this way on Delhi-Mumbai Expressway, I was able to get mileage of 18-19kmpl at 90kmph. This would not be possible on a NA engine.

Thankfully my use case is of primary highway usage and so this helps a lot. If the highway is busy, we can shift to sport mode and so this ensures engine RPM is high enough even at 70kmph to get max boost and better economy. That's why on many forums they mention that with sport mode, Nexon gets better highway mileage.

Let's talk about other fuel types and EVs and let me tell why I did not get a different vehicle. So first of all my current use case for next 3 years at least is primarily highway usage. CNG was rejected due to less number and overcrowding at the fuel stations. Diesel was rejected since my vehicle does not see daily usage and is stationary for the most part. Plus with BS -VI part 2, diesels have become much more complex and difficult to maintain with DPF related issues and what not. Also the arbitrary govt bans don't help. Last left are EVs. Looking around EVs have neither become cheaper in last 5 years nor have they become defect free. In Indian market as of 2025, there's no cheap and reliable EV. I really wanted to switch to an SV for low running costs but the headaches are just too much as of now. Unfortunately the Japanese auto makers seem to be dragging their feet so no high quality EVs in the market as of now. The homegrown car OEMs have EVs but the quality control leaves a lot to be desired. For example if the turbo blows up on my Nexon, it could cost about a lac or so, but if the battery blows up, and the OEM is not supporting, that would leave me in a hole of 5-6Lac. And that means scrapping the car and buying a 2L economy hatch again. So no, EVs need 5-10 more years to mature.

Well, long post but it does cover all I wanted to talk about. So far the Nexon seems to be decently reliable. Hoping it remains the same. Cheers!!