The Japanese make Bonsai miniature trees by stunting real ones. In this case, the result of altering the natural course of things is pretty.
When government stunts the natural growth of things, the result is usually not.
It’s also almost always expensive, too.
ASS is an engineering expedient, not a feature.
There was no market clamor for a system which automatically shuts off a vehicle’s engine every time the vehicle comes to a stop – as at a red light – and then automatically re-starts it (with a slight shudder as well as a slight delay) when it comes time to get going again.
ASS brought no tangible advantages to vehicle’s owner – and several disadvantages, among them the slight but noticeable shudder/delay at every stop/start cycle – as well as accessories such as the AC system that also stopped when the engine did, because such accessories are usually mechanically driven by the running engine.
When it stopped running, so did the AC.
Finally, there is the definite cost – as opposed to the above intangibles – of the wear and tear on the starter battery, which was never meant to handle such abuse.
Italicized to make the point.
The 12 volt starter battery almost all new cars have (the reason for that italics will become clear shortly) was designed to start the engine a couple of times or so each day. Not a couple of dozen time each day.
Here’s why that’s a problem:
The 12V battery starts the engine; the running engine recharges the battery – via the alternator, which also produces electricity to run the car’s electrical systems, such as the headlights, windshield wipers, stereo and the fan that blows warm or cold air into the car’s cabin.
While the engine is running, the battery recovers the charge it lost to start the engine. After the engine has been running awhile, it is fully charged up and ready to start the engine again.
But when the engine is regularly cycling off, the battery hasn’t got time to fully recharge – as no electricity is being generated by the not-running engine.
Then it is expected to re-start the engine.
In the meanwhile, at every stop interval, charge is being sapped from it to power the car’s still-on electrical accessories, such as the headlights and windshield wipers.
All of this is very hard on 12 volt batteries and that shortens their useful life. While the cost of buying a new battery every three or four years rather than every five or six isn’t great, it is high enough to negate the minuscule fuel savings – about 1 MPG overall- achieved by ASS.
That 1 MPG is an irrelevance to the car’s owner – especially when the cost of fuel is at its lowest ebb in decades. No one except a fuel fetishist would ask for ASS – pay extra for it – to save such a tiny amount of gas, especially given the unpleasantness of ASS. The constant shudder of the engine turning itself off and then back on, with that slight but definitely noticeable delay in between – which is aggravating to people who do not like delays.
Especially unnecessary ones.
But the delays – and other costs – are very necessary if you are a car manufacturer who has to achieve compliance with the federal fuel economy fatwa known as CAFE (Corporate Average Fuel Efficiency).
Uncle loves ALL CAPS acronyms; it gives heft to his edicts.
Well, one way to “save” gas is not to burn any. Enter ASS. Shut off the engine as often as feasible. The “savings” aren’t much per car, but CAFE compliance is calculated according to “fleet averages.” The 1 or so MPG ASS “saves” per car is factored over all the cars of its type built in a given year – and so is a significant savings . . . for the car company, in terms of compliance with CAFE.
ASS also makes it feasible to not have to further downsize engines – or reduce their power output – to achieve CAFE compliance. This is important from the standpoint of complying with customer needs and wants – which compete (and conflict) with the demands of Uncle.
But ASS has its costs, as detailed above.
Quadruple the voltage. Use a 48 volt electrical system to power a very high-torque starter/motor/generator, capable of near-instantaneous restarts, without the paint shaker effect of the 12 system. Power all of the formerly engine-driven accessories – the AC compressor, water pump and power steering – electrically.
So they never cycle off.
So people don’t notice a reduction in cooling (or heating) when the engine is off. And most of all, they no longer notice the engine shutting off.
Or coming back on.
In both cases, ASS is no longer objectionable – in terms of operational unpleasantness.
Expect to see more new cars with 48 volt systems, not just the high-end ones like the Benz GLE.
Because almost all new cars now have ASS.
However, 48 volts – and the other gear that comes with it, such as high-torque starter/motors and (in the case of the Benz) a lithium-ion (rather than lead acid) battery to store all that juice – doesn’t come free.
Either up front – what you pay for the vehicle – or down the road – what you’ll pay to repair the vehicle. Bet your bippie a 48 volt Li battery will cost more at PEP Boys than a 12 volt battery. And while you may never have to replace a drive belt – if accessories are driven electrically – you may pay a lot more than the cost of replacing one of those to replace the high-torque starter/motor/generator rig, in part because you will probably have to pay a pro to replace it.
A backyard DIY job this isn’t.
As a way around ASS – which we’re afflicted with because of CAFE – these 48 volt systems are pretty cool.
But cool isn’t free, either.
All to save a couple of MPGs – maybe – at a time when gas is cheaper than it’s been since 1965 – and the oil from which it is made more abundant than anyone ever imagined.
Expensive, complicated solutions – for a problem that doesn’t exist.
That’s Uncle’s “bonsai” tree: A gnarled and crippled thing which isn’t even pretty.
. . .
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