This topic has been all the rage in the industry for a while now. There’s been a lot of talk about its onset, complaints, benefits, screams of helpless rage for the V12s, tests, questioning and now some vague claims that downsizing is dead. It can’t all be true, right?
Surprisingly, much of it actually is true, despite how contradictory it all looks. Let’s see the big picture.
What is downsizing?
If we’re talking about cars (and we are), downsizing means putting smaller engines in cars instead of the previously used chunkier units. However, these smaller engines do NOT hamper performance. In fact, in many cases, they provide more power than their older counterparts.
How is this possible?
Well, they use modern tech to improve the efficiency of the combustion process and, most important of all, they have turbochargers. This enables them to produce more power, provide more torque in noticeably lower rev range and do all that with less fuel.
The most often used example is probably the 1.0 l EcoBoost made by Ford. The tiny turbocharged engine has several states of tune ranging from 99 hp to 138 hp. It replaced three larger engines from the previous generation and found its way to a number of cars from Ford’s lineup, including Grand C-MAX, a 7-seater MPV.
The reasons for all this are the ever-tightening emissions regulations and highly competitive market, the first one playing a far bigger role.
What is the problem with downsizing?
Nice so far, right? Well, in theory. OK, there are some cars which do enjoy a major boost in fuel efficiency and at the same time greatly improved driving characteristics. More power means that cars need less work to get to cruising speeds. This acceleration uses more fuel, but is shorter and causes less stress on the engine parts. Once there, you can lay off the throttle and your downsized engine will make use of the lower displacement to sip fuel slowly and also reduce emissions. This is most obvious with larger engines. The first E63 Mercedes-AMG in 2007 had a naturally aspirated 6.2 l V8 which produced 514 hp. The current one has a 4.0 l V8 biturbo which gives up to 612 hp and consumes more than 30% less fuel. It is greener, faster, more powerful and far easier on fuel. Worked great for the E63.
However, despite the reduction of 2.2 l, that still is a massive engine in a car that costs more than most houses.
Smaller engines have more problems. Turbocharging puts more strain on the engine parts and a small, delicate and cheaper engine will have problems with overheating. A great example of this is the 0.9 gasoline engine from Renault. In order to prevent overheating, as the temperature rises, its injectors shoot more fuel into the cylinders to cool them down. Not all of it can be burned, which causes higher emissions of hydrocarbons, fine particles and carbon monoxide. Of course, this is not portrayed in official emissions and fuel consumption figures. We all know that in real-world conditions, cars rarely reach the claimed consumption measured “the old way,” but some differences are just too big.
So, for some cars, this means that we got smaller, overstressed engines with reduced reliability which still consume just as much fuel in real world conditions as the older and bigger naturally aspirated engines. Sure, if you’re driving a small engine at the steady speed of 40 mph it will consume less, but most small engines are in small city cars and those are rarely at steady speeds. Most of their lifetime is spent accelerating and decelerating between traffic lights, so they are mostly in that fuel guzzling accelerating mode and the benefits of lower displacement at steady speeds are very rare. Additionally, their reliability and longevity are also reduced because of the additional stress.
Furthermore, the consumption of small engines is tested the same way as big ones. They keep the temperatures perfect and accelerate slowly and steadily. On the roads, accelerations are often far harder and conditions vary greatly. Now, when a car with a large engine needs to accelerate, it puts just a bit more stress on the engine components — barely noticeable for an engine that has a lot more to give.
But for a turbocharged engine with three tiny cylinders, this means that they have to double the performance and output. Now imagine doing that hundreds of times a day in your city commute. Driven sensibly, a bigger, modern engine can return fuel efficiency better than the stated one. Tiny turbo units can’t even come close to the stated values.
In short, real life conditions greatly diminish the value of the smallest engines. Simply put, there is a limit to how much you can downsize and at some point it becomes counterproductive.
What is the future?
Many manufacturers are investigating alternative technologies, such as electric turbocharging (Audi, Mercedes), water injection for improved combustion and cooling (BMW), variable valve technology and, of course, hybrid and electric tech. Unless they come up with a noticeably different system, we’ll have to say that simple reduction in displacement and adding a turbo have reached their limits of efficacy. Many manufacturers have actually started upsizing and thus improved their emissions.
Once again, some cars greatly benefited from reasonable downsizing. The mentioned E63 AMG is a great example. Sure, many aficionados miss the naturally aspirated 6.2 l, but that is a matter of preference and even they cannot deny just how much more efficient the 4.0 bi-turbo is in every respect.
But why do/did the manufacturers insist on downsizing to the point of getting ridiculously inefficient?
They were forced!
Government emissions regulations keep getting stricter over time. The rate at which they tighten up is familiar to all manufacturers, but simply using arbitrary desires as laws with no regard to the actual state leads to the point when manufacturers become “creative” in cheating in tests rather than finding new solutions. And it is not due to the lack of desire or knowledge. You can’t force physics with laws.
Aside from big things like the Dieselgate scandal, we’ve also grown accustomed to false consumption claims. A change in the measurement system discovered that simply ordering lower consumption and emissions is not the way to go.
Even the seemingly perfect solutions like electric cars have big downsides in terms of preserving the environment. Storing used batteries is a huge problem already. Imagine if the whole world drove electrics only. Furthermore, producing the electric energy that would fulfill such needs would cause major environmental problems.
So, what is the solution?
Reasonable middle ground! Downsizing brought immense improvement until it was taken too far, so not exaggerating is essential. If we rush into the electric-only era so quickly, we will have a whole new set of problems that many industry CEOs are warning us about.
Lawmakers have to be more realistic in their deadlines, but they also need to be stricter to the manufacturers that fail to meet them. We all know that we use more fuel (and consequently increase emissions) than the manufacturers claim, so how come the government is now surprised to find this out officially? Being strict while asking for an impossible thing has no point.
Be realistic, give breathing room to engineers and support development.