This engine was pretty green when we tested it, with right around 750 miles on the odometer. Also, since this RLX was the Advance model, it was fitted with nice looking, but hefty 19" alloy wheels (we weighed them at just under 60lbs apiece). On the dyno, with just under 260hp to the wheels, the RLX performed pretty well, but as you can see on the graph, this figure came in at 6000rpms, which is 500rpms below the specified 6500rpm horsepower peak. For some reason, the car's electronics wouldn't let us complete a full pass to the rev limiter, which results in an abbreviated horsepower curve. Even though we tested the car with the transmission set to the Manual/Sport mode, it consistently upshifted early at around 6300rpms. As you can also see on the plot, the slope of the horsepower curve showed a rate of increase of roughly 20hp per 500rpms, so if we were somehow able to get a full pull (all the way to the rev limiter) in, chances are the engine would have peaked at around 270-275 whp. To that, you could potentially add a few horsepower for an example with lighter wheels and a fully broken-in engine.

Dyno testing the RLX made all of its onboard diagnostics go bonkers, and there were a plethora of error messages appearing on the dashboard and the navi screen. Normally we will perform a run through the gears on the dyno for some eye candy, but this proved problematic with the RLX, as it would somehow "stick" at the rev limiter in either 1st or 2nd gear, whether or not we used the fully automatic "D" mode, automatic "S" mode, or manual "S", mode. We finally got one pass by lightly accelerating in 1st gear in "D" mode, then lifting the throttle briefly in 2nd gear. The transmission upshifted normally in 3rd and 4th gears.

Click the image below to view the full-size dyno sheet and continue on to the next page to see the video of the dyno pass.