BMW 3 Series (E90)
The BMW E90 series is the fifth generation of the BMW 3 Series range of compact executive cars, including sedan, station wagon (designated as E91, marketed as Touring), coupe (E92) and coupe cabriolet (E93) configurations. A high-performance BMW M3 version of the E90, E92, and E93 is also available. The E90 family succeeds the E46 model, and was launched in March 2005. In 2002, Norbert Reithofer and Development Chief Burkhard Goeschel started an initiative to halve the time it took to reach full production of the next generation 3-series from six months to three.[9] First marketed in March 2005, the car quickly became BMW Group's best-selling automobile worldwide, and by the end of the year 229,900 vehicles had been delivered.[10] It is by far the best-selling entry-level luxury car in Canada and the United States.[11][12] In 2008, the saloon underwent an extensive mid-cycle facelift. In 2010, the coupe and convertible were facelifed as well. Facelifted 3-series are commonly referred to as "LCI" (Lifecycle Impulse) models. The E90 has broad appeal being BMW's highest selling model, and being the highest selling luxury car in the US and Canada,[10][11][12] with numerous body style and engine choices it is a very flexible car that offers a wide range of performance levels including even the M3 which is based on the E90. To accommodate such a wide variety of roles the E90 is equipped with a fully independent suspension including aluminium MacPherson struts in the front, and steel 5-link Multi-link suspension in the back.[14] Front brakes have much more stopping power than rear brakes, and one fea ure of the E90's suspension is to allow very large, high performance front brakes. Also, the use of steel designed to provide high strength for casting applications allowed BMW to greatly reduce the weight and cost of the rear suspension, in addition, the rear axle can be completely pre-assembled and adjusted with the brake system and suspension. E46 comparison The E90 saloon is 49 mm (1.9 in) longer, 78 mm (3.1 in) wider and 9 mm (0.4 in) taller than its predecessor (E46). The wheelbase is longer by 35 mm (1.4 in). In previous 3 Series models, space for passengers and luggage were common criticisms; however, BMW made significant improvements to the poor leg and headroom in those previous models. BMW's brochure even highlights, 'Now long legs can be enjoyed even by the people who have them'. Large amounts of aluminium were used in the body work and suspension in an attempt to keep the weight close to previous models; however, the E90 weighs between 50 lb (23 kg) and 300 lb (140 kg) more than comparable older models. The N54B30 engine is all aluminium with cast-iron liners, while the N51 and N52 engines largely consist of aluminium with an outer shell of magnesium and even aluminium bolts to prevent corrosion from dissimilar metals. The cylinder sleeves in N54 are steel and have copper coating, while N52 have Alusil aluminium sleeves. The E90 also introduced run-flat tires to the 3 Series range. Consequently, cars with run-flats are not equipped with a spare tire. While these theoretically improve performance and handling, run-flats sometimes cost more to replace and can give a harsher ride.