The Diesel is the RPM paddle that isn't out yet. It cleared USA Pickleball on October 5 as the "Diesel 1" in 14mm and 16mm elongated, and that listing is the only public document on it: an EPP foam core under the same silicon carbide grit face RPM put on the Jade. Everything else, the weight, the swing weight, the price, the ship date, is RPM's to announce and they haven't.
I have one. It's in my bag now, and the question I'm playing with is the obvious one: the Jade already spins, so what does a different core buy you? No score until I've played it enough to defend one, and no numbers on this page that RPM hasn't put their name on.