
Car Engines: The incredible shrinking machine - e15ctr0n
http://www.economist.com/news/science-and-technology/21679767-internal-combustion-engines-are-getting-smaller-more-economical-and-cleanerall
======
cconcepts
Most people remember the analogy that if car engines had progressed at the
same rate as computing then a rolls Royce would run at 100,000 km/h and have
an engine the size of this full stop. Or something similar.

Ironically, it seems we're now at the end of the internal combustion era and
the abacus makers are desperately trying to refine a soon to be redundant
craft.

~~~
CompelTechnic
I think it will be a long time (100 years) until ICE's get replaced in semi
trucks and container ships. The energy storage requirements are massive, and
batteries for such applications have a much harder time justifying themselves.

~~~
cconcepts
You make a good point - small nuclear powerplants though?

~~~
jandrese
While the technical hurdles may be surmountable, the political issues are
probably intractable.

About the only viable green solution for container ships is going back to
sails. Some ships already fly sails (really kites) to reduce their fuel costs,
but it's not practical as the ship's only propulsion.

The best solution is probably to switch ships over to burning natural gas or
biodiesel instead of filthy heavy fuel oil, but the cost structure is all
wrong for this right now.

------
Derbasti
So "PS" is metric for horsepower. Who knew. (it's _German_ for horsepower, but
German horses are just as powerful as imperial ones, and not particularly
metric: PS literally means "Pferdestärken", i.e. "horse-powers")

The metric measure would be kW.

~~~
cardinalfang
Metric horses, though obsolete, are 98.6% as powerful as imperial horses.

------
rwmj
Europe really needs a Kei car classification.

[https://en.wikipedia.org/wiki/Kei_car](https://en.wikipedia.org/wiki/Kei_car)

~~~
seszett
What difference should this classification make compared to existing car
legislation?

Among the financial advantages mentioned on the Wikipedia article, only the
VAT (presumably?) break has meaning in Europe, or at least in France, since
the other advantages are either on taxes or requirements that don't exist here
(weight tax, road tax, adequate parking requirement) or insurance (which
already depends on engine power here).

It seems to be closer to the existing license-less car category, actually
(which are also limited to 50 km/h and barred from entering highways).

~~~
rwmj
Cars taking up physically less space could be taxed less (or, my preference,
large SUVs taxed more). You use less road space, less parking space, less
materials, so that is a reasonable tax policy. The UK has a road tax which
could cover this, but VAT could also be used to tax the car less at time of
purchase.

Current cars have settled on a certain size, for historical reasons. In fact
they seem to be getting a bit bigger. But there's no particular reason for a
car to be bigger than a single human being, or other sizes (two humans + one
suitcase perhaps). We can use the tax system to change that for the better.

This isn't a pie-in-the-sky unproven idea either. Kei cars are hugely popular
in Japan, demonstrating that the market exists.

They're pretty practical - I've driven in a 6 seat Kei-car in Japan, and there
are Kei vans and Kei flatbed delivery trucks (all fitting into the smaller
dimensions).

~~~
dagw
_Cars taking up physically less space could be taxed less (or, my preference,
large SUVs taxed more)._

Norway essentially does this. Taxes are based on engine size and (I believe)
weight. The relative price difference between a large SUV and a small, low
horsepower, hatchback is much greater than in most other countries. However
based on casual observations in and around Oslo, it doesn't seem to have a
huge effect on the size of cars people drive.

The real effect is the 'everybody' owns a Tesla since they are exempt for many
taxes and thus cost literally half the price of an equivalently performing
petrol powered car.

~~~
david-given
Car tax in the UK is based on carbon emissions. The table's here:

[https://www.gov.uk/vehicle-tax-rate-tables/rates-for-cars-
re...](https://www.gov.uk/vehicle-tax-rate-tables/rates-for-cars-registered-
on-or-after-1-march-2001)

It used to be based on engine size; for years I would get cars with as small
engines as possible, simply because it would drop my tax by about 1/3.

As for car sizes... it does seem to be having an effect here. A lot of people
I know go for small cars, preferring the little five-door hatchbacks. My last
one was a Honda Jazz, with a 1.2 litre engine and an absurd amount of space
inside; under the new tax system it'd be classed in category D (£110 a year),
but I'd be totally unsurprised if the next model made it into category C (£30
a year). My father has a diesel Nissan Note, about the same size, and that
_is_ in category C. He's very smug.

~~~
david_parrott
I drive a Vauxhall Insignia with a 2 litre 160ps engine. Also in band C. Also
smug. ;-)

------
ccozan
I recently switched from a 15 yrs old VW Golf IV with 1.6l and 100HP to a 2009
Tiguan with just 1.4l but 150HP.

I can't say that it has a better mileage but the power is there, the 50% more
HP makes a real difference. I was really skeptical at the beginning, but the
progress in engine design is indeed visible.

~~~
switch007
Your golf was a non-turbo petrol right? The Tiguan is a TSI which means a
turbocharger and a supercharger :)

------
vlehto
>Three-cylinder engines have a tendency to rock backwards and forwards around
the middle cylinder. Carmakers have come up with a number of ways to absorb
the vibrations and make sure such engines don’t shake, rattle and roll.

I'm skeptical how effective that is. Smells like planned obsolescence.

>These include more new materials, such as what the industry calls diamond-
like carbon (DLC) coatings for the surfaces of moving parts.

"Diamond like" sounds nice. But it's soluble to steel. I'd prefer Boron
Nitride or TiN by physical vapor deposition. But if other contact surface is
coated, then you might be able to use that DLC stuff. But if I recall
correctly, it's wear characteristics are not that miraculous in bearings.

~~~
thenewwazoo
> I'm skeptical how effective that is. Smells like planned obsolescence.

I'm not sure why it smells like that to you. Perhaps the word "absorb" is
insufficiently precise. The correct term is perhaps "counterbalance", and it's
purely mechanical. Some modern parts have fluid chambers and flexible rubber
components to damp oscillation, but that's not "planned obsolescence" because
the parts will very likely outlast the rest of the car.

~~~
vlehto
Four cylinders is inherently more balanced than three. Fatigue is the second
worst killer of mechanisms, right after corrosion. Vibration causes fatigue.
The best ideas to balance inherently unstable engine involve balancing axle.
But even they usually are not as good as inherently balanced.

~~~
thenewwazoo
But the entire point is that they've invented a novel mechanism for
counterbalancing vibrations that are unique to the three cylinder. When you do
that, you reduce vibration. This reduces fatigue.

It's worth noting as well that there's no such thing as "inherently balanced"
when you're talking about ICEs (except perhaps the inline 6). Four-cylinders
are inherently balanced in one mode (first harmonic), imbalanced in another
(secondary imbalance), and exhibit torsional effects that may as well be
imbalance.

~~~
vlehto
You have point there. No ICE is really balanced, there are 16(?) different
vibration modes and the best boxer 6 engines can deal with maybe 4 of them.

I have pretty strong gut feeling that the 1st harmonic is more important than
the 15 other modes combined. This far engines with odd numbers of pistons have
been exception. Until we go to single row star engines, but they got replaced
pretty quickly with two row star engines. Which can take the 1st harmonic into
account.

