Under the Hood

One of the apparently more innovative techniques automakers have applied to saving fuel is a concept borrowed from the electric or hybrid vehicle: automatic start/stop. The concept is fairly simple, turn off the engine when the car is stopped (i.e. at a stop sign or traffic light) and instantly turn the engine back on when the driver initiates their intent to commence motion (releasing foot from the break or depressing the clutch). Depending on the traffic patterns one encounters, fuel savings can be as low as a mere 0.5% all the way up to 10%. Truly this would seem to be getting something for nothing!

But as with any government mandated arbitrary standard there are unintended costs and consequences.  For example, prior efficiency decrees have compelled automakers to make their cars lighter – but lowering mass makes a car less crash worthy. To compensate as much as possible it became necessary to beef up the A, B, and C pillars (the front, middle and rear attachment points of the lower portion of the car to the roof) so passengers aren’t squashed in a rollover. That is, these pillars are now much wider and thus much more readily obscure objects behind them at a distance. Don’t believe me? Hold out your thumb at arms length and place it in front of a car 50 feet away; now unfurl all 5 fingers and block it with your hand. Completely disappeared now hasn’t it? Those of us who drove cars from the ‘80s or earlier are well aware of this slow change. Unfortunately anyone younger just assumes it’s totally normal to have a 6-8 inch A pillar blocking one’s view of oncoming traffic as they try to merge. Such actively growing blind spots have ironically led to more accidents, injuries, associated health care costs, repair costs, higher insurance rates and in some cases even death. But hey, what is human life worth when weighed against the “environment”?

In other words, there are costs associated with everything. If it were up to the individual to decide for him or herself how much more safety risk they are willing take relative to increased fuel economy that would be one thing. However it is quite a different story when the choice is taken away and there is only one option allowed for all. That is what government is: the removal of choice. Bureaucrats decide on the “best” route and make all other options illegal. The same removal of choice is now happening with these automatic start/stop systems. Starting with model year 2016 they are becoming more and more prevalent. Why is this? Because of government fuel economy standards like CAFE (or it’s European equivalent) mandate FLEET wide averages. Therefore the ability by the automaker to extract even a few small percent increase in fuel efficiency multiplied by a fleet of thousands or millions of vehicles helps them meet those standards and avoid possibly millions of dollars in fines. The problem, however, is that the cost of meeting those standards is shifted to the consumer. Such systems require larger, beefier starters and batteries – which cost more. Due to more frequent use these components will wear out sooner – which costs more. Ironically the greater the fuel savings, the more the engine will be damaged. Engines are most vulnerable at start up due to lack of oil. The longer it sits off the more the oil drains back down. Obviously an engine that has to be replaced or rebuilt on a more frequent basis is going to be a significant cost to the owner.

In other words, there is no free lunch. Even something seen (fuel savings) has an unseen cost (wear and tear and repairs). Fortunately, for now, we are permitted the ability to override and turn these systems off (although it must be done manually with every cold engine start). But there is no doubt that in order to eke out another 0.1% of CAFÉ fuel savings, automakers will soon remove the option to disable this feature. Then again perhaps it doesn’t really matter as soon enough the government will outlaw human drivers and we’ll all be passengers in self-driving cars within 30 years – cars that some are already discussing whether or not the automated “brain” behind it should sacrifice its passengers if it determines more deaths would result by protecting its occupants. Unintended costs indeed.

3 thoughts on “Under the Hood

  1. Bob Kobelski

    Good basic point about no free lunch but the engine shutoff is a bad analogy. Oil drain in the short time between shut down and restart will be small. Microprocessor technology stops the engine with on cylinder just beyond top dead center so only a spark is required to restart, not a cranking of the starting motor. – at least that’s the Porsche implementation.

    CAFE is also not well presented, what CAFE means is that a significant change in a high volume model will permit a continuation of gas guzzling for a limited production luxury model.

  2. Greg Morin Post author

    Re: oil drain, that’s why I qualified it with “the greater the fuel savings” – that is, if it is off cause you’re stuck in traffic for 10 minutes the savings is great, but then the engine is definitely lost most of its oil back to the pan by that point. Short stops, true, it is minimal, but cumulatively it all adds up. But, all the cylinder’s can’t stop just before TDC, only one… they all fire in sequence so only one cylinder can be the closest to TDC which the remaining that much progressively away from it.
    Re: CAFE, your comment is correct as well… my point is dovetails with yours though, in that it is a “fleet” average (which allows them to do as you describe). That same fleet averaging also plays into what I describe, small incremental changes multiplied over a large fleet benefits the automaker relative to meeting these regulations.

    1. Bob Kobelski

      OK valid point about savings versus oil drain and wear. Only need one cylinder to fire to get the engine running, especially when it’s hot. I think you want to have the piston after TDC since it will have zero velocity when the spark is fired.

      My understanding of CAFE is that a manufacturer’s fleet must hit a certain mileage target – all Fords sold must have an average fuel economy of “XY” mpg – not must increase by a certain amount. So Ford needs to sell “N” Fiestas to compensate for every Mustang GT and the problem for Ford arises when not enough people want Fiestas versus the Mustang GT buyers.

      Nonetheless, the unintended consequences of an act (of government in this case) is an important point – and largely the point of the original “Freakanomics” We cannot predict the unintended consequences until they hit us in the face.

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