Cars and Calibres

Engines, efficiency, and why we are often our own worst enemy


A recent discussion in an online group we had concerned the modes available in modern cars.

In particular, they were talking about how nice “sport” mode was, but how anaemic the regular or intelligent or standard mode was.

This ability to choose quickly and easily the dynamics by which you arrive at your destination is something that used to be mainly in the more expensive luxury and sport vehicles, but today, these choices are now more available on a wider range of cars.

What many don’t realize is that this “mode” choice isn’t always about providing you with a more fun drive as it is about meeting certain environmental and efficiency parameters.

If you have three engine modes, which we will generically call regular, sport and sport plus, they will all eventually arrive at the same peak power number.

It is just that standard will arrive there with a bit more need to push the pedal down; sport plus will be tuned to react to your door most quickly; and sport will be somewhere in the middle.

Different manufacturers have different ways of adjusting to these possible dynamics.

In some cars, a flick of the switch will give you immediate feedback in terms of the revs going a little higher. In others, you may not notice until you give it some gas.

Also, nowadays, the engine controls are being increasingly synced with other computer-controlled systems.

Modern transmissions may react differently based on the chosen mode: choosing normal or the more lethargic gears to improve efficiency, or holding gears longer in sport or sport plus when you want to pull out maximum power.

In reality, more of the advancement in modern automotive efficiency and environmental friendliness comes from more transmission development than from engine technology advances.

We have eked out a lot from internal combustion over the last decade, and they are now looking elsewhere to move things further forward.

When we are asked about car efficiency, we always stress that the variable with the most impact in the equation is the human.

I personally used to get just about 5 kilometers to a liter no matter what I did or what I drove. I just had habits that were not in any way efficient.

However, in modern cars that benefit from much smaller engines, such as Audi’s 1 liters, I will get significantly better.

I attribute this to the fact that no matter how heavy my foot, the car is designed to not let me break out of a certain range.

Let’s take another example. A daily driver Subaru Legacy 2.5 Turbo with a very plain old-school automatic (it’s only a few years old, but doesn’t benefit from the efficiencies of continuously variable transmission gears or double clutches) will, in regular traffic, get less than 5 kilometers to a liter.

However given the slightest bit of open road that allows you to open up the throttle, I easily see 8 to 9 to a liter. And that’s not the highway yet that’s just thrusting and cutting in a way that should be inefficient.

On the highway, I will get above 10 even if I am seriously on the throttle. So heavy feet and slow traffic are really the worst enemies of the efficiencies we are trying to reach.

Another thing to note is that these cars aren’t actually aimed at getting us to be personally more efficient necessarily.

The car companies need to reach certain levels of fuel efficiency and environmental emissions. The modes and the engine controls allow them to do this.

Also, the companies often have to work based on numbers for their entire fleet. If their fleet is mostly large European luxury cruisers or sportscars, they may have to be more aggressive with the software adjustment than someone who makes primarily small cars with small engines.

Now, while it may be that these systems are in place more for corporate requirements rather than personal driver needs, we are seeing the benefits.

We can get more efficiency than before, and that doesn’t come with the soul-destroying drops in power we have to bear with.

Audi 1 is a good example. So is the three cylinder in the Mitsubishi Mirage. Triples used to shake like crazy, but they are now much smoother.

True, this comes at the cost of increased computer control, which comes at the cost of, well, increased cost when we have to bring a car to the authorized service center for even the slightest thing.

Still, they are safer than ever because of all this computer control.

It turns out, we humans were the most uncontrollable variable.

Get Inquirer updates while on the go, add us on these apps:

Inquirer Viber

latest stories