I was just reading about Toyota's new engines for the Rav4 (2AR-FE) and Venza (1AR-FE). While quite oversized (IMO), they do implement some interesting technologies that backup Toyota's claim that its a 'low-friction design'.
It incorperates:
- An offset crankshaft
- Roller rockers for the valvetrain
- Three stage variable oil pump
- Reduced tension piston rings (I can see Metro going OOOOohhh as he reads this one)
- Reduced tension auxiliary belt drive
- Tumble air control valve (enhances combustion while the engine is cold)
- 12 hole high atomizing long nozzle fuel injectors
It also has all the normal goodies like VVT on intake and exhaust cams as well as ACIS intake system (dual runner intake manifold).
Too bad they don't quantify any of the gains.
source,
and this too.