"The 3.0-liter, 24-valve, DOHC inline-6 is essentially a bored and stroked version of the 2.5-liter engine found in the 325is, hot-rodded for more power and torque. Mid-to-low-end torque is improved primarily by the larger dis­placement—with a 2-mm stretch in bore and a 10.8-mm lengthening of stroke. A horsepower increase at the top end comes from (among other things) a ported and polished cyl­inder head, more aggressive cam ­shafts, heavy-duty valve springs and a freer-flowing exhaust system.

BMW uses the VANOS (Variable Nockenwellen Steuerung) cam timing system, which means Variable Camshaft Control, to get both a smooth idle and good power at high revs. This is an electro-hydraulic system in which electronic sensors use oil pressure to shift cam timing. The cams operate four valves per cylinder through hydraulic lifters, which require no periodic servicing.

The result of these modifications is a substantial increase in horsepower and torque over a broad range, and a consid­erable improvement on the standard 325is engine: an output of 240 bhp at 6000 rpm, versus 189 at 5900, and 225 lb-ft of torque at 4250 rpm, compared with 184 at 4200.

Naturally, the suspension has had a going-over as well, with larger, stiffer springs, added damping on the rein­forced gas-charged struts, larger anti­roll bars and reinforced control arms, front and rear. Suspension changes also lower the ride height 1.2 in.

Outward signs of high performance, as mentioned, are somewhat more subdued than they were on the M3’s predecessors. The M-car is treated to a body-colored front air dam, a rear apron with an air diffuser to reduce body lift, and sculpted side mirrors. There are also discreet M3 badges on the door trim and sills. For those who want a little more show (as well as pre­sumably enhanced high-speed aerody­namics), there is an optional rear spoil­er. A sunroof is also available."