Nissan March K12

Lakshitha Wickramarathna · July 17

Some people say that the Nissan March K12 1000cc engine isn't as fuel-efficient as the 1300cc engine. Usually, when the engine capacity is low, fuel economy is high. What could be the reason for that?

Both are automatic transmission!

matroska · July 17

40 minutes ago, Lakshitha Wickramarathna said:

Usually, when the engine capacity is low, fuel economy is high

This is not always the case. When idling over a finite time - Yes a smaller engine would consume less fuel. So if you sit in traffic a smaller engine will burn less fuel compared to a larger engine. Things change when you're moving.

When moving, accelerating etc a smaller under-powered engine has to exert itself a lot more than a larger more powerful engine. Imagine you enter a highway and need to accelerate to 100 KM/H and maintain it - the smaller engine car will need to rev more/work harder to achieve and maintain that speed. Thus consume more fuel.

Think of this scenario - you give a child and an adult to move some a cubpoard and you give them soda . The child will struggle, run out of breath and will be very tired and he'll probably drink two glasses of soda. Same cupboard is no big deal for an adult he will simply move the cupboard and have a small drink of soda since he doesn't really feel to tired or out of breath.

The K12 march is a heavy(ish) hatch the larger engine will efficiently perform when accelerating and moving. The smaller engine will be stretched -hence thirstier. This applies for other Nisans as well the B14 1.3 L Nissan Sunny is a lot less fuel efficient than its 1.5 L counterpart.

In Sri Lanka, the smaller engine the better belief goes back to the 80's when cars like the KE72/74 corolla wagons, Corolla AE80/81, Sunny B11/HB11 etc had 1.3 and 1.5 variants, those cars were very spartan, and light - 1.3 was more than enough to efficiently drive them around. 1.5 was more powerful but a little bit of overkill and yes in idling they would have burnt a little bit more fuel. Hence people generally say smaller engines are more fuel efficient. But really it all boils down to power to weight ratio. The engine should be powerful enough to drag that car efficiently.