Munich’s considered a master of the six cylinder engine.
The fact its second-gen M3’s humble 3.0-litre inline six closely matched its greatest ever, the McLaren’s 6.1-litre V12, on specific torque, power, and peak power revs, enforces legend.
The accolade was further cemented by the third-generation M3 and its 3.2-litre straight six. Not only could the DOHC 24-valver wind up to dizzying revs with 252W, it made 114Nm from every litre of displacement. Today’s a HSV Clubsport R8 LSA makes 108Nm per litre.

Slapped on the back of the 1400 lucky E46 M3s, engineers tweaked its cam profiles and gave it a bin-sized carbon fibre intake manifold. Powers jumped by 13kW to 265kW, and torque figures a measly 5Nm to 370Nm, but it wasn’t revered for numbers. It was the sound.
We once best described the resulting shriek to be like a “Formula One car with a sore throat.” And after hearing the car again at The Bathurst 12 Hour, where BMW Oz brought along its sole heritage example, we agree. It’s utterly, wildly, intoxicating.

A lot has changed about the company’s M halo coupe. It has a new number designation and turbochargers, but its ethos stays the same. At least for the M4 GTS we also had along with us.
Something of a successor to the M3 CSL, the GTS repeats the same formula with less weight (no rear seats), sports focus (roll-cage), and a two-door body style. And it boasts outputs the old M3 could only dream of (a water-injection assisted 368kW/600Nm).
But can the CSL’s younger brother muster a better bark? We lined up the two in the carpark to see whether the GTS’s Akrapovic assisted growl has moved the game forward. Tell us which you think sounds best.