Most automotive enthusiasts know that cars tend to lose a bit of power with age and use, as wear and tear can take its toll on a car’s internals. On this episode of LegitStreetCars on YouTube, the host Alex shows just what kind of horsepower numbers his beater AMG’s hand-built engine can put down after almost twenty years and 178,000 miles of abuse.
This car is ‘roached’ as they say. It’s been beat up, driven hard, fallen apart, and rigged back together again. It probably isn’t worth much more than the $200 that Alex paid for the car. Judging by the missing intake tubes and the shoddy booger-weld exhaust, chipping bondo rust repair, and horrific paintwork, it hasn’t been cared for very well.
At the risk of completely blowing up the engine, the owner decides to give it a few runs on the dyno to see exactly what is left under the hood after all this time. For reference, a Mercedes AMG C43's M113 all-aluminum twin-spark 24-valve 4.3-liter V8 engine was rated from the factory at 306 horsepower and 302 lb-ft of torque. That rating, keep in mind, is at the flywheel, while a dynamometer measures horsepower at the wheels.
With an automatic-equipped car, you can usually expect at least a 15% horsepower loss when going from crank numbers to wheel numbers, which would give the car around 260 horespower to the wheels brand new. Over three runs, this particular car averaged 231 horsepower and 225 lb-ft of torque. Sure, it’s unlikely that this bodged-together Merc is still capable of a 5.7 second 0-60 time, but that power loss seems pretty reasonable to me.