The Camry, Avalon, Tacoma, ES 350, IS 350, GS 350 and RX 350 share versions of the factory V6 and the IForce 5.7L V8 is in the Tundra, Sequoia, Land Cruiser, GX 570 and LX 570. The Rav4 shares a motor with its Lexus sibling and so on. I don't think we will ever see the day where both brands develop bespoke motors for their line of cars. Way too expensive and to what end? Some motors, say for Lexus "F" cars and the current LS 500, are bespoke and likely to remain that way until Toyota well and truly joins the horsepower wars, if it ever does. To call the technology in the LS 500 3.5L twin-turbo V6 next level is to diminish its impact upon the internal combustion world. It is that significant and that amazing. If I can find the link where I originally read about it, I will post it up.My belief to this, is that according to reports Lexus has "parted ways" and has become more independent from Toyota in order to shed the Toyota feel/vibe. This was done in order to give Lexus a more up-market and indy image. Thus, no Lexus engine would be used in a Toyota Supra as it would be contrary to the push to seperate Lexus from Toyota. I have spoken.