Why an Automatic generally returns lower mileage?

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When I go on the road, it seems like everyone has a gear-less scooter. It has become so popular and prominent due to its extreme convenience and unisex appeal. It is as simple as Start – Stop. A no non-sense machine. But that comes at a compromise which you have to accept. Terrible mileage. Though the fuel consumption figures have largely improved lately, but still when it comes to real world conditions, you know!!!

If you own an Automatic or simply an automatic scooter like Activa, you should be instantly able to connect to this article.

So again, why an Automatic returns lower mileage?…

Hmmm. A seemingly trivial question which is actually not so trivial. Well, a layman would answer, “ Just because its an Automatic! ”. But again, why?

An automatic vehicle is one which changes “gears” on its own instead of depending on the driver, as in a Manual. When I mention Automatic, it refers to a “Continuously Variable Transmission” abbreviated as CVT and also applies to “most” other vehicles. Yes, there are exceptions.

What affects the mileage or fuel consumption of a vehicle?

The obvious reason could be the efficiency of the engine itself i.e. how good it is burning the lowest amount of fuel for maximum output. An engine is a highly complicated piece of machinery. Modern engines are just about 30% efficient (Exceptions exist). This number is what we have been able to achieve over a period of almost 100 years.

But, the most significant one is the “Transmission”.

In a manual vehicle, there are gears which deliver fixed “mechanical advantage” or just simply a variation in speed. In a CVT vehicle, there are no separate gears – the reason why CVT is “considered” to have very closely spaced Infinite gearing. Gear ratio is varied continuously as per the driver’s riding pattern.

A CVT is essentially a variable speed belt type transmission having two conical stepless pulleys. On this arrangement, the belt traverses both the conical pulleys thus effectively varying the gear ratios.

Now the big question, where is the Neutral gear? When the engine is ON, the belt runs but it doesn’t drive. The special mechanism of CVT prevents the wheel being “driven”, thus putting the vehicle in Neutral. When the engine speed increases, the belt starts driving the wheel – starting from a “virtual” first gear.

So, what could be the reasons for lower mileage?

  1. Belt driven

A CVT has a lot of losses, just because it is a belt drive while gears have very minimal losses when compared. CVT has a distinctive problem called a “Rubber-band” effect which in turn causes poor response time, causing waste of energy.

  1. Variable gear ratio

Because a CVT has “infinite” gear ratios and we don’t have any control over it, it is highly likely that the transmission is operating at an inappropriate gear ratio causing a drop in mileage.

  1. Frequent start – stop

If you are driving in a city, a CVT will make everything worse by becoming “thirsty”.

  1. Poor Driver skill

CVT is easy and sometimes fun to ride. Any Vespa fans? So, every engine has an optimum RPM at which the engine supposedly should return the highest mileage possible. But its highly impossible for most drivers to ensure that the vehicle is accelerating within that RPM range.

  1. Trying to ride it like a KTM, damn!

In a manual, you have complete control over both the gear and RPM. In a CVT vehicle, the moment you wide open the throttle, every virtual “gear” change will happen only in that particular RPM.

So, at the end, what you can do is change your driving habits. Be gentle on your vehicle and you can instantly see the difference.

Drive your vehicle like yours, not like your friend’s 😛 😉 If you know what I mean!

Save fuel. Drive more.

Wish you a Happy and Safe Diwali 🙂


Image credit: Aprilia, featured here is SR150.


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