the S4, won’t be far behind. Visual clues include the defacto quad exhaust pipes and Audi’s hexagonal grille insert reserved for S models. Little else has changed in comparison to other A4 ...

Aside from the diesel engine, the S4 is the latest Audi to gain a 48V electrical system ... with an offbeat growl to the exhaust note. As with the larger S6 and S7, the unit also makes the ...