Team Penske tested and further developed the engine in secret in the winter and spring of 1994. Before Mercedes-Benz joined the effort, the engine was initially called the "265E", which followed Ilmor's standard naming convention for their dual overhead camshaft engine. This was ostensibly to maintain in-house secrecy of the pushrod project, from those working within Penske and Ilmor who were not made fully aware of it. It was mated with the in-house Penske chassis, the PC-23. It was introduced to the public in April, just days before opening day at Indy. Rumors quickly began to circulate that the engine was capable of over , which was up a 150-200 hp advantage over the conventional V-8s.