Tuesday 19 May 2015

Green Socks

Imagine Fred.  He received a pair of green socks as a present from his wife, to reflect their shared interest in the environment and green technology.  He was very pleased with them, and immediately decided to wear them for his forthcoming business trip, which would involve an 800km drive.  Normally, his car would achieve a comfortable 600km on a full tank of gas, but on this occasion he was surprised to find that he made the entire trip without having to stop to fill up.  On the return trip, with his green socks now in a laundry bag in the trunk, he was chagrined to have to fill up at the 600km mark as per normal.  Reporting this odd situation to his wife, she immediately concluded that the green socks must have been responsible.  After all, what else could it be?

The two of them laughed at the idea, and it became a running joke between them.  But the next time he repeated the trip he wore the green socks again, and to his amazement once again completed the 800km outbound trip on a single tank of gas.  This time, however, he washed the socks in his hotel room and wore them again for the return trip.  And sure enough, he made the return trip without the need to fill up.

Fred was nonplussed, but not wishing to look a gift horse in the mouth he bought himself a complete drawer full of green socks.  After a short while it became clear to him that by wearing green socks he could effect up to 25% improvement in his gas mileage.  However, when describing the incredible results to his friends and colleagues, he was surprised to find that they laughed him out of the room.  They were full of reasons why it could not work.  He was retiring his lead foot every time he put green socks on.  He was only wearing the green socks when driving routes that were inherently less demanding on gas.  Winter had since given way to summer, and fuel economy naturally picked up in the better weather.  There was only his word for it that the claimed improvements ever existed in the first place.  It was all in his head.  It was a placebo effect.  Where was his double-blind test data?  They had all their arguments neatly lined up, and for the most part none of them were even willing to try it out for themselves.  A few, though, did dip their toes in the water, and as a rule reported tangible improvements in their own fuel consumption figures.

I’m sure you see where I’m going with this, but the fact remains that this sort of thing does indeed happen in the tightly-spec’d, observed, tested, and regulated world of consumer automobiles.  Better fuel consumption is ALWAYS at (or near) the top of most car buyers’ needs and wants list.  Even so, if a car manufacturer’s engineering department suddenly starts promoting green socks, you can be sure that their marketing department is ready and waiting to ensure that they won’t see the light of day.  The thing is, consumers are generally dumb, and oftentimes even if you offer them what they say they want, if you don’t package it correctly they will reject it - sometimes quite irrationally.

I can think immediately of two example, and they both come from Germany, where a solid engineering mindset is more deeply ingrained than in many other manufacturing cultures.  One imagines that even German heads of marketing all have engineering degrees.

First up, BMW in the 1980s.  This was when the diesel engine craze was starting to sweep Europe.  Diesels were popular because they delivered massive gains in fuel economy, which is what European consumers with their hyper-pricey gasoline were demanding.  But BMW’s engineers correctly pointed out that theoretically, diesel fuel offers barely more than a potential 5% gain in fuel efficiency when compared to gasoline.  Instead, diesel engines gain their impressive economy through the fact that they are fundamentally red-lined at not much more than 4,200rpm, and friction losses are way lower at lower revs.  BMW figured out that if they took their 2.8L petrol engine, optimized it for peak performance at low revs and limited it to 4,500 rpm, they would be able to replicate the expected performance of the 2-litre diesels that their competitors in Europe were touting.  Thus was born the BMW 528e.

BMW’s first mistake was in calling it the 528e rather than the 520e.  The last two digits in Bimmer-speak would announce the engine size, and the engine was actually 2.8 litres, so that’s what the German mindset mandated for its nomenclature.  However, their customers now expected 2.8 litre performance, even though BMW tried to make clear that it was actually offering 2-litre diesel fuel economy.  Their second mistake was in calling it 528e rather than 520d.  I have no idea what ‘e’ (for ‘electronic’, apparently) was intended to convey, and I guess their customers didn’t either.  But if ‘d’ makes customers think ‘Diesel’ then that should have been a good thing.  In 2015 BMW’s marketing department are a lot less pedantic about having their vehicle nomenclatures reflect the actual internal specifications.

The BMW 528e was actually a technological tour-de-force, but its commercial failure proved instead to be an engineering embarrassment.  Not long after, BMW relented and offered proper smoke-belching diesels that sounded like a London Taxi when idling.  They had a ‘d’ appended to their model numbers, and customers snapped them up in droves.

Second up is Audi’s initial foray into CVTs (Continuously Variable Transmissions).  A car’s gearbox is a compromise.  Whether manual or automatic, almost inevitably 99% of the time it will be in the wrong gear, and either the ideal gear will not be available, or changing to one of the available gears cannot be done quickly and accurately enough to apply the required correction.  The problem can be ameliorated to some extent by adding more and more gear ratios to the gearbox.  Manual transmissions which used to come with four forward gears now have six gears as often as not.  And automatics with up to 8 speeds can be found.  Even so, the ideal situation remains in theory a CVT.  With such a transmission, the engine can always be in the theoretically perfect gear, regardless of the conditions.  The thing is, though, that the electronic brainpower needed to figure out the ideal gear ratio several times a second requires a modern computer-controlled vehicle management system.  Thus it was that in the early 2000’s, Audi’s “Multitronic”, with its highly sophisticated electronic management system was one of the first high-performance CVTs offered to the market.

Multitronic was brilliant.  Finally, Audi drivers for the first time found themselves perpetually in the correct gear.  But the result was a disaster.  What happened was that, although the car was indeed always in the exact, optimally correct gear, the gear that it chose was not the one that the drivers felt it should have been in.  Like I said at the start, consumers are dumb.  They are used to the sound of a car see-sawing its way through a sequence of fixed gear ratios.  But that’s not what they heard.  What they thought they were hearing was an automatic gearbox with a blown torque converter, with the engine speed spooling up and down unexpectedly.  New Multitronic Audis were driven in droves back to their dealerships by owners complaining of faulty transmissions.  They refused to be mollified by assurances that not only were these vehicles working perfectly, but that they were actually working better and more efficiently that anything they had previously driven.  Unfortunately for Audi, a dumb customer (and specifically a dumb Audi customer) will not accept that he is dumb.

Audi’s engineers were forced to re-map the electronic management of their Multitronics so that they would mimic the behaviour of a conventional automatic transmission with a limited number of fixed gear ratios, a task they performed, one imagines, wearing paper bags over their heads.  The result was something that threw away all of the advantages of the CVT, but which dumb customers at least were not bringing back to their dealerships.  Finally, in 2014, Audi discontinued the Multitronic, and disavowed CVTs in general.  In the meantime, many other manufacturers are now selling CVT-equipped cars with transmission mapping systems that behave correctly - just like those early “failed” Multitronics.  My daughter has such a car, and she for one has no pre-conceived notions of how an automatic transmission “should” sound.

Tomorrow, I’ll return once more to Fred and his green socks.  And computer audio playback.