There you go mate,in an answer its the engine type.

You had better get the scoob power up mate,as aint much between them right now



The S54 Engine is one of the best ever! Used in the BMW E46 M3, the BMW M Z3 Roadster and the BMW M Z3 Coupe. Voted International Engine of the Year and class winner of Engine of the Year for 3 straight years!

Here's what the judges said:

The 343bhp powerplant, which is housed in the M3 coupé and revs to a maximum of 8,000rpm, puts into practice know-how such as Double VANOS variable valve timing and cross-flow cooling for the cylinder head. Known within BMW as the S54, this 24-valve powerplant, which incidentally also won this category last year, boasts 365Nm at 4,900rpm and benefits from a bespoke engine management system with two 32-bit microprocessors that perform 25 million calculations per second. Once on the road, this eco-friendly engine – the vehicle is able to deliver 8.5L/100km (33.6mpg) – goes in hunt of supercars: while the M3 can’t quite keep pace with category rivals such as Porsche’s 3.6-liter 911 Turbo or Ferrari’s 360 V8, the vast majority of drivers are going to find the zero to 100km/h (62mph) time of 5.2 seconds more than satisfactory. The longitudinally mounted M Sport-developed engine also has race-car-like throttle response.

The S54 shares its format with other BMW inline 6-cylinder engines. Virtually all of its engineering details, however, are unique and oriented to the very highest level of performance. Given that other current BMW “sixes” have an aluminum block with cast-iron cylinder liners, it may be surprising that the S54 M3 engine has a cast-iron block. Why?

Compactness is the primary reason. An inline six is longer than a V-6, and BMW nurtures the inline layout because of its superior smoothness and sound. An aluminum block’s cylinder liners take up space; with liners it would not have been possible to achieve the engine’s 3.2-liter displacement without lengthening the block. The second reason is strength. Given that this engine develops a fully 333 hp from 3.2 liters – significantly over 100 hp per liter – its internal stresses are immense.

The S54 engine has stepless Double VANOS , which varies valve timing on the intake and exhaust camshafts. Though Double VANOS is employed in current 3, 5, X5 and Z4 Series 6-cylinder engines, in the M3 engine, it varies timing over a wider range and contributes in a major way to the engine’s stratospheric power output. Intake timing is varied by 60°, exhaust by 46°, vs. 40° and 25°, respectively. As in all BMW engines where it is employed, VANOS is hydraulically actuated in response to electronic controls.