BMW M’s Secret CSL Garage Features Previously Unseen Goodies

BMW M has a garage filled with never-before-seen prototype CSL models.

byNico DeMattiaJun 12, 2022 2:06 PM
BMW M’s Secret CSL Garage Features Previously Unseen Goodies
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Over the past five decades of BMW M's existence, it hasn't made many CSL models. In fact, it's only made three--the original BMW 3.0 CSL, the E46-gen M3 CSL, and the brand-new M4 CSL. That's it. So you can imagine BMW fans' excitement when the M Division recently revealed an entire secret CSL garage, filled with prototype cars no one's ever seen before.

In a recent video, BMW M showed off three different secret CSL prototypes that were made but never before revealed to the public. There are apparently many more to come but, for now, we just get to see the three. Thankfully, they're three pretty special cars.

E60 M5 CSL

The first one shown in the video is also probably the best one--an E46 M3 CSL V8. Essentially, the engineers at BMW M took an M3 CSL, ripped out its 3.2-liter naturally aspirated inline-six and stuffed in a 4.0-liter V8 based off of the E39 M5's 4.9-liter V8. It was also the test-bed for BMW's "S65" V8 that powered the E92 M3. In the M3 CSL, the big V8 made 424 horsepower, which was 64 horses more than the standard CSL. It also featured a second air intake, adding symmetry to the previously asymmetrical intake of the normal CSL. Aside from the new engine, though, everything else was the same--the same frustrating SMG transmission, the same lightweight materials, and the same classically good looks.

BMW also developed an E60-generation M5 CSL, which would have made it the only four-door CSL in history, even to this day. For CSL-duty, the E60 M5's 5.0-liter naturally aspirated V10 was upgraded to 5.7-liters, which bumped its peak power to 621 horsepower, up from the standard car's 500 horses. Despite upping the displacement, BMW also upped the already sky-high redline, jumping up from 8,200 rpm to nearly 9,000 rpm. The M5 CSL also got a carbon fiber roof (a first for an M5), an M-colored livery, and a Formula 1-like exhaust note. More importantly, BMW even recognized how annoying the M5's SMG transmission was, so for CSL-duty, the E60 M5 instead got a dual-clutch auto from Getrag.

E63 M6 CSL

The last car shown is probably the least exciting--an E63-generation BMW M6 CSL. The Bangle-era BMW M6 was never a good looking car and, for CSL-duty, it barely looked any different. For the M6 CSL, BMW really seemed to focus on active aerodynamics, which would still be unique in BMW's lineup today. It had an active front splitter, underneath the front bumper, and an active rear wing. No current BMW models have active aero, so the M6 CSL would have been a big deal back in its day. BMW also toyed with aerodynamic mirrors, which are shockingly similar to those on current M cars, showing where the design was started. Though, BMW didn't up the power for the M6 CSL, leaving its 5.0-liter V10 alone.

Apparently BMW M has even more secrets to show but that will happen in future videos. It's cool to know BMW has these prototypes stashed away, in perfect museum-ready condition. Although, it's also mildly annoying these cars died in the prototype stage, as they all would have made great additions to BMW's history.