850cc - C63/E63 AMG M156 6.3

I was a bit worried about fitment, but these 850cc injectors plugged right into the M156 rail without any issues. The flow matching is spot-on, and the car idles smoother than it did with the old set.

The matched set of 8 arrived perfectly balanced, and the fitment on my M156 was spot-on for the 2007-2014 C63. Idle is dead smooth and the car pulls harder up top.

Swapped these in over the weekend and the idle smoothed right out—the matched set of 8 made install straightforward since they’re all consistent. For a 2010 C63, the 850cc size feels like the right middle ground for my setup. Solid upgrade, just make sure your tune is ready for the bump in flow.