Friends,
I’ll cede the argument that modern cars are cleaner and more efficient than they’ve ever been. Sure, there have been many marques through our history that have been stingy with a gallon of gas, and some that have produced fewer emissions, but the entire fleet currently on sale beats those outliers by every measure. Why? We asked the robots to help out and they’ve agreed.
Is this a problem? Of course it is. And it isn’t, or at least wouldn’t be, if lawyers weren’t involved. Here’s a short example:
Back in the olden times of a decade or so ago, when you wanted electricity to light a spark plug to cause an explosion in an engine’s cylinder, you’d rely on a spinning top called a distributor.
Through a gear meshed with the camshaft, a shaft spins a piece of metal that makes contact with a post that sends electricity to a wire leading to a spark plug. It’s simple until you start thinking about how an engine in a car is used. As engines speed up and slow down, you want the spark to occur earlier or later, so maybe you add weights to the spinning top that move a plate forward a bit when the engine spins faster. This is lovely and elegant, you think. But you don’t want that advancement to go too far or else the spark comes too soon—even before the cylinder is full of the fuel mixture. Detonation, knocking and other badness ensues. How do you control the advance?
Specially tuned tiny springs.
Hold on, there’s more alchemy. When you mash the gas pedal to the floor (How quaint! More on that in a sec.) in your Curved Dash Oldsmobile, engine vacuum drops and if you send that signal to a vacuum motor attached to that plate, you can further advance the spark timing to catch up.
With me so far? Sucking and springs and centrifugal forces are changing when the spark is happening. Archaic with a capital arc. (I crack myself up sometimes.)
So what’s changed? Sure, computers, but what’s really changed has been the quality and number of sensors in a modern engine. An engine management computer cannot only know vacuum, and engine speed, but also atmospheric temperature and pressure, overall system voltage, throttle position at the throttle pedal, fuel quality, and a lot more.
What this means, simply, is that you can throw away distributors and let the computer tell individual plugs exactly (well, sort of exactly, hold on) when to fire. You put high-tension ignition coils directly on top of the plugs and the computer just turns them on and off. Easy, right? The computer can look at all the inputs, decide what’s going on and how much power is needed, and let ‘er burn.
But it’s not that easy.
For instance, you could theoretically make more power with more spark advance over a longer period of time, but the implications are many. For instance, if your, ahem, 285 horsepower engine could make 305 horsepower or more with a simple software change from the manufacturer, will your insurance rates go up? Is that too hot for the engine block over time, increasing warranty repair costs? When the home mechanic could change a couple springs and gain power, the manufacturers aren’t on the hook.
Here’s where this gets weird.
Original Equipment Manufacturers (OEMs, if you will) don’t release the code that drives engine management computers. Some don’t even release service manuals to the public. What this means is that backyard mechanics, hot rodders, and aftermarket equipment manufacturers are left to make educated guesses about how the engines in the vehicles they’ve purchased actually work. What signals come from where to make which thing work the way it does? After all, your gas pedal isn’t connected to the engine anymore. It’s just another sensor, but this one measures the angle of your ankle to represent how fast you think you want to go. If I want to make a widget that adjusts the power my engine produces and make an incorrect guess at how this affects all of the other systems, I guess this makes me that much more liable for my error, but wouldn’t it be much better if I got it right the first time? More later…
Your pal,
– bob
