Much of the credit for the MazdaSpeed 3’s prodigious power output goes to the turbocharged engine’s direct-injection design. As with the MazdaSpeed 6, the 3’s injection system sends fuel directly into the cylinder at very high pressure, creating a cooler, denser air/fuel mixture that results in increased torque, quicker turbo response, and lower emissions. Fuel economy is surprisingly decent too, though you will need to feed it a steady diet of pricey premium (91 octane) fuel, and put a block under the accelerator.