I am trying to understand the sounds I hear from the engine in my 2012 Ridgeline (J35Z5) when I accelerate from low speed around 1500
RPM or climb a hill, a faint clattering under load reminiscient of preignition. One must listen closely. The Honda dealer showed me that this is normal by letting me drive another Ridgeline; the same sound is there. Perhaps the VTEC activating under load?

 

wrong section. Moving to Ridgeline

 

No. VTEC activates by letting you jump in acceleration. It almost feels like turbo kicks in, and it should do it 3 times, as cams adjust 3 times.
What you likely to hear is rocker clutter on valves. Unless they did it different on Ridgeline, Hondas have adjustable lash on rockers. For 2012, it is unlikely lifters are sticky, to cause gap.
I'd say, let a good independent listen to it. Tsa-tsa-tsa-tsa?
Or, simply switch to better gas. Sometimes cheap gas gives such clutter.