Audi and its two prestigious German rivals are locked in serious sales combat in the midsize SUV crossover market. Audi’s Q3 recently received a midlife makeover to increase its fitness for the fight.

Audi's 2.5-liter five-cylinder engine shouldn't exist. Yet it does, and transforms the RS3 into a stealthy exotic with daily-driver practicality.

Inline-five engines have been around since the '30s, but it was only in the '70s that they started to really work. That's all ...