Daily Archives: March 18, 2012

The years following the passage of the first automotive emissions standards in the… 1

The years following the passage of the first automotive emissions standards in the early 1970s until the mid-to-late 1980s is often referred to by car enthusiasts as the malaise-era.

The name comes from the fact that between smog standards and fuel economy requirements, engines lost much of the power they produced in the 1960s and driveability was often severely degraded. The problem was that sensors and electronic control systems such as they were at the time were expensive and generally crude at best. In order to modify the behavior of engines to clean them up, engineers came up with elaborate systems that used actuators powered by the vacuum produced inside an engine when the throttle is closed.

Lift the hood on any car from that era and you'll find a rat's nest of black rubber vacuum hoses running here, there and everywhere. Thankfully, by the late 1980s and early 1990s automotive engineers were able to start taking advantage of the increasingly powerful microprocessor technology that was at the heart of the personal computer revolution. With CPU's, sensors and electrically driven actuators a new golden age of motoring was born.

While it's true that fuel economy standards didn't increase from the late 1980s until just a few years ago, average power outputs doubled in that same period. That means the engineers were actually able to double specific fuel efficiency in that 20 year period by getting twice as much power from the same amount of fuel.

I'll leave the discussion of why they chose to double power instead of absolute fuel efficiency to a later post.

For those that don't recall those engines from the time when I was taking auto mechanics in high school, check out the Honda Civic vacuum hose routing diagram that Murilee Martin found to get an idea of what mechanics of that period had to deal with on a regular basis. It's no wonder that these engines often ran poorly. A leaking vacuum line could easily make an engine stall altogether.

#cars #malaise_era #vacuumhoses

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Quick, Why Won’t This Car Pass the Smog Check? | The Truth About Cars
I've had more Honda Civics than any other type of car (at least one example of each of the first five Civic generations), at one point owning two '85 hatches

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