F stands for Fenomenal (Lexus IS F)
Based on the platform that underpins the IS 250 and IS 350 sport sedans, the IS F is a carbon-spewing, tire-vaporizing mutant, the gentrified Lexus family's black sheep (and you know how much fun black sheep can be). Given Lexus's carefully cultivated reputation for civility, the rip-snorting IS F shouldn't even be here. And yet, by sheer force of will (see sidebar), it is. Lucky us. For sure, nothing else in the Lexus stable has the IS F's street-bruiser look. Two inches wider up front than the IS 350, the F also sports a larger grille (improved engine cooling), fat brake ducts in the front air dam, 19-inch, dark-gray BBS forged-alloy wheels, quad tailpipes in a dual stacked array, and a pronounced hood bulge that hints of something menacing lurking underneath.
It's in there. The engine, based on the direct-injection 5.0-liter V-8 that serves in the LS 600hL, was codeveloped by Yamaha; it's upgraded with new high-flow heads, hollow cams, a head-scavenge oil pump (to help maintain even lubrication during high-g loads), titanium intake valves, a dual-inlet air intake (the second intake opens at 3600 rpm for enhanced high-rpm breathing), and other performance goodies. The net result is 416 horsepower at 6600 rpm and 371 pound-feet of torque at 5200. (motortrend)