One of the biggest questions people have about the new M3 and M4 models surrounds their power output and, of course, the engine under the hood. Now, you might be tempted to say that this S58 engine has been around for quite some time now and you’d be right, as the X3 and X4 M models had it for nearly two years now. However, the engineers in Munich are known to tinker with their mills and they usually adapt various settings for the car they are going to be used in.
It was the same with the S55 engine. When it was originally launched, a lot of people (myself included) complained that it was simply too brutal and piled on torque way too suddenly, leading to sudden loss of traction. Over time, the S55 engine was modified, and towards the end of its production cycle you could actually enjoy it throughout the rev range. But how does the S58 compared to its predecessor?
The guys from Evolve put a new BMW M3 Competition on the dyno to try and find out. Their test featured a car with a broken in engine and the first service done, so the figures should be as accurate as possible. Their results showed the M3 Competition had about 469 HP at the wheels along with 435 lb-ft of torque. Pilling on a transmission loss of anything between 10 and 15 percent, the crank numbers should be between 516 and 539 HP. A bit over the manufacturer’s claim of 503 HP.
This makes the new S58 engine a bit more powerful than the old one, which was measured at 421 HP and 386 lb-ft. The graph also shows a different power delivery, with a much stronger top end on the new S58. The output is actually pretty close to what you would get out of a Stage 2 S55 engine and that’s quite an improvement on what are basically two 3-liter straight six mills at the end of the day.