Some Misconceptions About Car Engines

It is good sometimes that we understand the basics ad the mechanism of a car. How it works, the capacity and lots more. The engine is the heartbeat of any car and it initiates all the functions and how the car responses to other components.

Here are some misconceptions about the car engine that some car owners take for granted.

• They have a lifespan
  Engines are made with an estimate on how long they will last. Of course, carmakers are not going to advertise this (no matters how durable it is). Simply because in the customer’s mind these things are seen as permanent. When something breaks in the engine, they see it as a fluke. It is not a fluke.
• Small does not mean better MPG
  Although smaller engines have less rotating mass and are lighter on their feet, it does not mean they are always efficient. Under-Powering a motor puts it at a significant disadvantage. Now, this weak little thing needs to work at its maximum capacity to keep the car going. As you near the car’s maximum capacity, efficiency drastically falls! Sometimes a slightly larger engine will get better MPG.
• You spend almost no gas while idling
  A 2.0L 4-cylinder engine will spend about 0.2 gallons of gas per hour while idling. That is close to nothing. It scales evenly as the engine size grows larger. A 5.0L V8 will spend about 0.5 gallons of gas while idling.
• When you let off the gas pedal, you spend NO gas:
  Modern-day engines (anything in the last 20 years pretty much) will spend literally no gas if your foot is off the gas pedal while it’s moving. It will use the fact that your car is in motion to keep spinning, not gas.
• Jumping on the gas quickly is bad:
  Bad for the longevity of the whole drive-train, not only the engine. Burns up extra gas for no reasons and it isn’t comfortable. Why do people do it? Get on the pedal in a gradual fashion. Mechanical things do NOT like speeding up or slowing down quickly.
• Steady wins the race:
  Want to get good MPG? Stop decelerating and accelerating constantly. These are both inefficient actions. Keep your foot on the pedal in a way that it will keep the speed at the place you want, constantly.
• They spin/move FAST:
  Even spinning at 2,000 RPM which is an average cruising engine speed, they are really moving. Let’s take an average-sized engine, another 2.0L 4 cylinders! The height of the cylinder is about 85mm. Less if it has a compression ratio of 10:1, then that means the piston moves 76.5mm every time it goes up. Let’s round it at 75mm for simplicity! Every revolution, it moved up once and down once. So the total travel distance of a piston per revolution is 150mm. If it is moving at 2000RPM, that means it travels 150mmx2000 per minute. That is 300,000mm per minute. If we convert that to per second, we get 5,000mm per second. If we convert the mm to meters we get 5 meters per second! There are 4 pistons simultaneously doing this. Now, if we pushed the engine to its 6,000 RPM red-line, that would put it at 15 meters per second. That is fast.
• Turbo does not mean better MPG:
  The number of times I’ve heard “it’s got a turbo. Gets great gas mileage!” makes me almost want to believe it myself. But the MPG gains do not come in the fact that it has a turbo. They come in the fact that turbo engines are usually downsized! The downsizing is where you get the MPG gains from. In fact, a turbo engine that is being driven hard will actually get worse MPG!