My car search has finally been reduced to Suzuki Ciaz and Honda City. Suzuki Ciaz comes with 4 speed AT whereas Honda City comes with CVT. Which transmission is better in terms of fuel efficiency and long term maintenance? My driving is mostly in the city with the occasional long distance trips (once a month).
In the same car, fuel efficiency will be better with the CVT:
- a CVT can keep the engine near its optimum rev range better than a 4-speed automatic.
- an automatic has higher power losses due to the torque converter.
A torque converter is locked up when possible, but when it's open it causes noticeable power losses (up to 20% in bad cases). In tests where a car with manual gearbox is compared to the same car with an automatic gearbox, the automatic has the higher fuel consumption.
Most CVTs have a computer-controlled clutch instead of a torque converter.
The answer gets a bit more complicated in the case of the Honda City: this has a CVT with torque converter. Unusual, but there you go. Honda claims the CVT + torque converter is 10% more efficient than a normal automatic.
You're comparing a Suzuki Ciaz with 68 kW engine and empty weight of 1010 kg to a Honda City with 87 kW and empty weight of 1050 kg. The fuel comsumption figures stated by the manufacturers are: Suzuki Ciaz 19.12 km/l, Honda City 18.0 km/l.
The difference in engine power and weight can account for the better fuel economy of the Suzuki, compensating for the inefficiency of the transmission. Or the 2 companies used different methods for measuring the fuel efficiency - that's not visible on these websites, though.