Moving on from the Innova Crysta
Rahul Vikas, Bengaluru: I am looking to upgrade from my 2017 Toyota Innova Crysta and have shortlisted the BMW X5 and the Mercedes-Benz GLE 400d. My usage is on broken roads and long-distance journeys, so a soft suspension and comfortable seats are a priority. Which of these best fit my bill?
The X5 is a nicer car to drive. However, on bad roads, the GLE has a better ride and absorbs broken roads better. The 400d engine is also smooth and has sufficient punch to make driving a pleasure.
A question of engines
Eswar, Hyderabad: If a 1.0-liter turbo engine provides more mileage and performance, then why use a 1.2-liter petrol engine? What are the pros and cons of both?
The difference between a 1.0-liter turbo-petrol and 1.2-liter naturally aspirated petrol engine is the former tends to be a three-cylinder unit, while the latter usually comprises four cylinders. A three-cylinder engine produces unbalanced vibrations due to the reciprocatory action of two pistons in the same direction, while that gets balanced out in a four-cylinder engine.
So, in real-world conditions, a 1.0-liter engine would feel more noisy, jerky and sluggish in its power delivery at lower RPMs, and also filter some vibrations into the cabin or clutch pedal. To counter the vibrations, carmakers generally use a balancer shaft and also equip the engine with a turbocharger to improve low-end torque and throttle response, which is further improved by an automatic transmission. On the other hand, a 1.2-liter engine would feel significantly smoother at idle and off the line, thus allowing for better in-city driveability and gradually building pace thereafter.
Now coming to the fuel efficiency, even though three-cylinder engines are lighter, and a turbocharger minimizes the airpumping losses inside the engine, the real-world figures depend a lot on the driving style. Since the meat of the powerband in turbocharged engines lies at higher RPMs, it is tough to obtain consistently high economy figures if one wants to extract the maximum performance. In comparison, a 1.2-liter naturally-aspirated engine would end up consuming less fuel for a similar drive experience.
In a nutshell, a 1.0-liter turbo-petrol engine will be suitable for a driving style aimed at extracting maximum performance from the vehicle, while a 1.2-liter is for a relaxed and comfortable daily commute, with occasional fun at high revs.
Hormazd Sorabjee is the editor of Autocar India. Mail your feedback and queries to [email protected]