
The new cars debut at October's Sydney motor show and go on sale soon after, although BMW dealers are already taking orders for them.
And, following industry trends, both 5 and 6 Series cars now come with starter buttons as standard.
The more potent 4.8lt engine is borrowed from the new 7 Series and boasts increased power and torque.
The 225kW 4.0lt V8 - also from the 7 Series - debuts in the new 540i. That model also gets a swag of additional equipment over the straight six-cylinder 530i, including: twin 65mm-diameter chromed tailpipes, alarm system, lumbar support, headlight washers, adaptive Xenon headlights, 18-inch Star spoke alloy wheels, satellite navigation, TV tuner and voice recognition, BMW's ConnectedDrive (no cost for the first year) and High-Beam Assist.
The new High-Beam Assist monitors traffic conditions and independently activates or deactivates the car's high beam lights, to avoid dazzling oncoming traffic.
BMW's six-speed automatic Steptronic gearbox is standard.
Claimed 0-100km/h time is 6.3 seconds.
The 550i replaces the current 545i and boast 25kW more power and 40Nm more torque than the outgoing model. Maximum power is 270kW at 6300rpm and maximum torque of 490Nm arrives at 3400rpm.
BMW says the new car shaves 0.3sec off the 545i's 0-100km/h time.
The 550i also gains High-Beam Assist and Head Up Display. High-Beam Assist becomes a standard fitment on the 650i Coupé and Convertible.
The newcomers also get a redesigned iDrive Controller and the start/stop button on the instrument panel.
Apart from the revised V8s, additional safety and comfort features of the latest generation DSC+ are now standard across the 5 and 6 Series cars. Benefits of that system include Hill Start Assist, Brake Standby function, Brake Drying function, Brake Fade Compensation and Comfort Stop features.
Bluetooth mobile phone preparation becomes standard on 525i, 530i Touring, 530i and 530d.
Both new 650i models replace the 645Ci and offer the same increase in power and torque as the 550i does over the previous 545i: 25kW more power and 40Nm more torque.
Recommended retail prices for BMW 5 and 6 Series:
5 Series
525i: $92,900
530i: $111,500
530d: $113,500
530i Touring: $117,500
540i: $133,500
550i: $160,000
6 Series
650i Coupé: $201,000
650i Convertible: $217,400