It’s good to see Sreten from M539 Restorations getting more and more popular, as he really is putting out some of the best car content on the YouTube machine at the moment. One of his more interesting projects, of which there are many, is his “Project Chicago” E65-generation ALPINA B7. The E65 7 Series is infamous for being among the most problematic Bimmers of all time and yet not only did Sreten take one on as a project car, he did so with the ALPINA version, which is even more specialized and harder to source parts for. However, he’s restored the B7 back to near-perfect condition and gave it quite possibly the best detail job I’ve ever seen. So in his latest video, he took it to a dyno to see just how healthy it is.

From the factory, the E65 ALPINA B7 used a heavily tuned, supercharged version of BMW’s N62 engine. So it’s a 4.4-liter supercharged V8 making a claimed 500 PS (493 horsepower) and 516 lb-ft of torque. So after fixing up its engine, Sreten wanted to see how much of its original power remained. However, it wasn’t as straightforward as that.

See, Sreten’s car is a U.S.-spec car, hence its name, and therefore has a different state of tune than Euro-spec cars. Why would that make a difference? Fuel. In the U.S., we have pretty crappy fuel compared to Europe, with a much lower octane rating. Even out premium pump gas is usually only 91 octane, which isn’t as high as Euro stuff. So when the engine detects the higher octane, it reverts to a different state of tune, to keep things running safely. That caused the power output to be much lower than expected, at around 457 horsepower.

After that, Sreten dove into the car’s software and realized there are three different states of tune that ALPINA built into the ECU: one for U.S.-spec, one for a lower-octane Euro fuel, and one for the high-octane Euro fuel. So Sreten needs to tune the ALPINA B7 to use the high-octane Euro-tune, so he can unlock its full potential in Germany.

Still, 457 horsepower is nothing to sneeze at and it’s probably still fantastic to drive. Especially since it’s a proper ALPINA V8 with some glorious supercharger whine. But if Sreten wants to truly finish his project, and get the ALPINA B7 in top-top shape, he’s going to have to give it a tune.