In lieu of painting a Picasso Guernica picture for you, here is our stick-figure explanation: volumetric efficiency is the percentage of achieved air-intake volume in the cylinders of an ICE (internal combustion engine) versus *available* (calculated/theoretical) volume. Naturally aspirated engines typically cap out at 100% (under normal circumstances in an Otto Cycle engine), and anything 80% or higher is considered “good.” However, most of us want our race cars to go-to-11, so we (or some awesome manufacturers from factory) will slap on a forced induction system to compress the air and exceed 100% (as high as 130% or higher) in order to burn more fuel (stick it to the man!) and obtain higher torque and horsepower output at higher loads. Turbochargers are the more popular and efficient choice of forced induction. They use exhaust gas pressure to turn the turbine wheel on the wastegate side (otherwise, this would be wasted in the form of waste-heat energy), which is attached to, and thus turns a compressor wheel in the compressor housing on the intake side, which is where air is - you guessed it - compressed and sent through an intercooler, which helps cool the air before reaching the cylinders. As the air temperature decreases, the air density increases, and the VE goes up, which is why turbos are also known to have even greater effect in colder climates (a.k.a. “turbo weather”).

 

So, give your ride a healthy dose of Vitamin VE for a good boost. …and maybe wear it, too: