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The Bottom Line:
The M-specific styling touches are nice, but the 2008 BMW M5 isn't anything you haven't seen before.
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M5, like all M BMWs, doesn't shout its superiority with gaudy embellishments
unique front face to distinguish it from other 5 Series sedans
all 5 Series models get styling enhancements for 2008
One key credo of BMW M is high-rpm, so this V-10 is engineered to rev eagerly to its somewhat astounding 8250-rpm redline with some small sacrifice in low-end torque…which, trust me, won’t be missed. Lightweight reciprocating components are used throughout, which also helps reduce total vehicle weight and balance front/rear weight distribution to near 50/50. There are three power and throttle-response settings: the P400 default mode (for valets and your son’s prom night) caps the engine’s horsepower at a mere 400 and gives normal throttle response; P500 unleashes all 500 horses with quicker response; P500 Sport (for track work and
BMW’s Valvetronic system, which controls fuel/air intake via valve actuation without a throttle, is not (yet) developed for high-revving engines, but this M V-10 does use double-VANOS variable camshaft control on both chain-driven intake and gear-driven exhaust cams. And, like all M engines, each cylinder has its own electronically controlled throttle. Its ultra-high 12:1 compression ratio is enabled by an ultra-quick ionic-current system that senses knock at each spark plug and retards ignition timing of individual cylinders to prevent it.
The “semi-dry sump” oiling system uses two reservoirs, a small one ahead of and a larger one behind the front frame crossmember, separated by a baffle. A mechanically driven variable-volume oil pump delivers sufficient pressure, but never excess volume, at all times for all operating conditions. Two electrically driven scavenger pumps recover it from pickup points determined by the Dynamic Stability Control system’s lateral-g sensor (to account for cornering loads), and a recirculating pump moves it from the front to the rear main reservoir. Cooled by a coolant-to-oil heat exchanger, its temperature and level are monitored by sensors that drive an oil temperature gauge (in the bottom of the tachometer) and a low oil level warning lamp. (Curiously, BMW has decided that coolant temperature gauges are not useful and has eliminated them from most models, including this one. We strongly disagree.)
