Sometimes an engine can save a car. Such is the case with the E60-generation BMW M5. When the E60 5 Series first debuted, its styling was controversial and polarized the fanbase. There’s a good reason for its styling, which BMW’s then-design boss Chris Bangle told us, but no one knew that then, so people only criticized. It was also too complex, overly reliant on fussy electronics, and too heavy for customers that were used to the brilliantly simple E39 5 Series. However, BMW M stuffed a 5.0-liter free-breathing V10 under the hood and everything changed.

Ask a typical BMW enthusiast if they’d like to own an E60 535i and they’d likely say no. However, ask any BMW enthusiast if they’d like to own an E60 M5 and the answer would be a near-unanimously emphatic “yes.” And it’s all because of that V10 engine.

One of the highest-revving V10 engines of all time

BMW’s S85 engine, the 5.0-liter naturally aspirated V10, was as unique then as it is now. Not only does it make 500 horsepower but it revs to 8,250 rpm, making it one of the highest-revving V10 engines of all time. While screaming to its stratospheric redline, the S85 engine makes a delicious, motorsport-like noise. It’s one of the most enjoyable, charismatic engines the Bavarian brand ever made and it’s one that charms everyone that drives it.

What’s interesting is that the car wrapped around the engine wasn’t all that beloved back in its day. Its steering, while sharp enough, felt a bit soft for an M car. Its suspension, too. It also had far too many customizable settings, an impossible iDrive system, and its SMG gearbox was a nightmare to use. In Europe, the latter was the only transmission available, while North American customers had the choice of a proper manual. But for SMG owners especially, the E60 M5 wasn’t always great to drive.

Top Gear once criticized the car

I still remember the old Top Gear episode, in which Jeremy Clarkson reviewed the E60 M5 for the first time and criticized the hell out of it. Then, he pressed the “M” button and it completely transformed. See, back in those days, that sportier mode actually unlocked more performance, it didn’t just make the artificial steering weight heavier. Without the M button, it only had 400 horsepower. But pressing the M button unlocked all 500 ponies, sharpened the gearbox, and put the limited-slip diff in a more aggressive setting. That completely awakened the sleeping beast and suddenly made drivers forget about its maddening iDrive screen and chunky curb weight.

It wasn’t just its power, though. Sure, 500 horses are nice, especially when the car could use all the power it can get. Instead, it was the character of the engine that made the E60 M5 so exciting then and still so exciting today. Its smooth linear power band is incredibly refreshing after driving modern turbocharged engines with their tidal wave of sudden torque. Its hair-raising V10 soundtrack at 8,000 revs was and still is intoxicating, and its sharp throttle response made it feel light and immediate.

The E60 M5 isn’t the best looking M5, it isn’t the best handling M5, and it isn’t the most reliable M5. In fact, it’s probably among the worst of all M5s in those categories. However, its engine alone makes it one of the coolest BMWs of all time and absolutely worth investing in.