And instead of two valves per cylinder, most cars now have four or even five valves per cylinder. That allows the engine to breathe better, taking in air and sending out exhaust much more quickly and efficiently.
We even have variable valve timing, which adjusts the opening and closing of the valves for maximum power and efficiency at different engine speeds.
There’s coil-on-plug technology, which sends a much higher voltage spark to each cylinder, with almost no power leakage, since each cylinder gets its own, dedicated coil.
And in the past few years, cars have adopted gasoline direct injection, sending the fuel-air charge into the cylinder at very high pressure, at just the right millisecond.
Then there are turbos, twin-turbos, tri-turbos, quad-turbos, superchargers and turbo-supercharger combinations. Electric turbos and electric superchargers are coming, too.
All of this is why you now see full-size sedans getting plenty of power from four-cylinder engines, when they used to need six- or eight-cylinder engines.
And soon we’ll be seeing more three-cylinder engines. When you can easily get enough horsepower out of three cylinders, why not save the weight and add to your gas mileage?
In fact, you already can get a three-cylinder engine in a subcompact Ford Fiesta that produces a very respectable 123 hp. It’s a one-liter engine, Gary.
Can power steering fix itself?
Dear Car Talk:
I have a 2003 Toyota 4Runner with about 150,000 miles on it. I bought this vehicle used about a year ago. It looks great, and has been a great, dependable vehicle so far. Toward the end of the winter, however, I started having issues with the power steering. Then it completely failed. My mechanic told me that I'd need to replace the rack and pinion. So I started saving up for the repair, and lo and behold, the power steering went back to normal, even after driving for extended periods of time. Needless to say, I would like to save the cash for other things. Did it fix itself? What could explain why it failed and now seems fine again? – Luis
Ray: The weather. Failing steering racks are famous for misbehaving just like this in colder weather.
Perhaps you’re too young to remember the great Rack-and-Pinion Epidemic of the 1980s. It hit GM cars particularly hard, so we know the symptoms well.
In cold weather, things shrink. See the Seinfeld “shrinkage” episode if you need any further elucidation on that.
Back in the ’80s, GM’s problem was that certain seals inside the rack would shrink in colder weather. And when they shrank, they’d allow power-steering fluid to sneak by them, causing a loss of pressure. That caused the power steering to fail, sometimes only in one direction. The only solution was a new rack.
The symptoms were always worse when the weather was cold. And they tended to go away after the car was driven for a while, because everything heated up under the hood.
I don’t know if those same seals are causing your problem, Luis. It could be one of the valves, too. Or something else. But if your mechanic investigated and says you need a new rack, he’s probably right.
And based on historic temperature ranges, I’d say you have until around Columbus Day to save up a thousand bucks or so. Good luck.
Visit the Car Talk website at www.cartalk.com.