Mazda says the new diesel unit has a remarkably low compression ratio of 14.8:1 and a bespoke variable turbine geometry turbocharger. (drivemag.com)
In some vehicles with lower compression ratios, running a higher than prescribed octane may actually do more harm than good. (moneysense.ca)
The 383 - cubic - inch Magnum engine was detuned to 300 horsepower by lowering the compression ratio for improved emissions. (media.fcanorthamerica.com)