Ilmor co-founder engine guru Mario Illien says his company would require substantial financial backing to enter F1 as an independent engine manufacturer.
Illien, who partnered with Mercedes to become McLaren's engine builder in the 1990s, casts a positive eye on Formula 1's future engine platform, but does not see his company entering the sport anytime soon.
"In principle it is the right direction -- the technology must become simpler and cheaper," the Swiss engineer told Auto Motor und Sport.
"But for a private manufacturer, we cannot do it without outside help.
"I could not develop a business model like we have in Indycar, because I would have probably only one or two customers. And if one does not pay the bill, I'm dead.
"Without a sponsor behind me I could not build this engine for Formula 1."