Kicking off at $39,990 before on-road costs for the entry-level 118i, the base price for the German hatchback is up by $2000, though the flagship M140i hot hatch is nearly $5000 more affordable at $59,990.
Headlining the updates for the 2018 range include the company's iDrive 6 infotainment system as standard across the range, with 125i and M140i versions nabbing the larger 8.8-inch Navigation Professional version.
There's a new high-gloss black finish on the centre stack, "cleaner design elements and smoother joins" throughout the cabin, new upholstery stitching and chrome elements for the electric window controls.
More interior finishes are available too, such as a Pearl Chrome trim and Dakota leather in Cognac. Full-LED headlights are standard across the range, with the M140i scoring adaptive units.
Standard equipment on the 118i and 118d ($43,990) includes the Sport Line styling package, 16-inch alloy wheels, Navigation System Business, climate control, DAB+ digital radio, rear-view camera, sports steering wheel, speed limit info, front sports seats finished in cloth, rain-sensing wipers, BMW ConnectedDrive services, along with the company's driving assistant.
The 118i is powered by a 1.5-litre three-cylinder turbo petrol engine shared with the Mini range, developing 100kW of power and 220Nm of torque, while the 118d is motivated by a 2.0-litre four-cylinder turbo-diesel with 110kW and 320Nm.
In terms of performance, the 118i can sprint from 0-100km/h in 8.7 seconds, while the 118d completes the benchmark in 8.1 seconds. Fuel use for the petrol and the oiler are rated at 4.8L/100km and 3.8L/100km on the combined cycle respectively.
Stepping up to the 120i ($45,990) swaps in a 2.0-litre turbo petrol four producing 135kW of power and 270Nm of torque, which propels the little hatch from 0-100km/h in a more brisk 7.1 seconds. Fuel use is a claimed 5.8L/100km combined.
Extra equipment over the 118i/118d twins includes the Urban Line styling package, larger 17-inch alloy wheels, LED fog-lights, front and rear parking sensors, interior lights package, Dakota leather upholstery, 'extended' automatic climate control, and an anti-dazzle interior mirror.
Next in the range is the sporty 125i, which kicks off at $49,990 before on-roads. Compared with its lesser siblings, the 125i get the M Sport Package with M Sport suspension as standard, along with 18-inch alloy wheels, exterior mirrors with anti-dazzle function, M Sport brakes, high-gloss 'Shadow Line' exterior trim highlights, Navigation System Professional with the larger 8.8-inch central touchscreen, cloth/Alcantara upholstery, M leather steering wheel, a sports-tuned transmission and a BMW Individual Anthracite headliner.
Under the bonnet of the 125i is an uprated version of the 2.0-litre turbocharged four-pot, in this tune developing a meatier 165kW of power and 310Nm of torque. Acceleration from 0-100km/h takes 6.1 seconds, while fuel use is rated at 5.9L/100km on the combined cycle.
Finally, the flagship M140i ($59,990) gets Jet Black 18-inch alloy wheels, adaptive M suspension, adaptive LED headlights with BMW Selective Beam, comfort access, full Dakota leather upholstery, electric front seat adjustment with memory, along with a harman/kardon audio system.
The Bavarian hot hatch is driven by a 3.0-litre turbocharged inline six, developing 250kW of power and 500Nm of torque, helping the M140i sprint from 0-100km/h in just 4.6 seconds. Fuel use, meanwhile, is rated at 7.1L/100km combined.
All versions of the 1 Series send drive to the rear wheels via an eight-speed automatic transmission as standard.
Several option packages are on offer across most trim grades, including the Innovations Package, Driver Assistance Package and the Comfort Package.
The Innovations Package ($1800) is available on the 118i, 118d and 120i, and includes Navigation System Professional, extended ConnectedDrive Concierge Service, and enhanced smartphone connectivity. For the 120i the pack also adds the HiFi Loudspeaker audio system.
Next up is the Driver Assistance Package, which is available across all grades bar the M140i. Extra equipment includes High-Beam Assist, adaptive cruise control with stop & go function, parking assistant, and anti-dazzle interior and exterior mirrors, along with front and rear parking sensors.
The assistance pack is an additional $1800 for the 118i /118d, $1400 on the 120i, and $1000 with the 125i.
Finally, the Comfort Package is available for all variants except the M140i - costing $2100.
Additional specification includes comfort access, electric front seat adjustment with memory and lumbar support, along with front seat heating.
The updated BMW 1 Series range will arrive in showrooms from September 2017.
Note: Overseas model pictured
2018 BMW 1 Series pricing
118i - $39,990
118d - $43,990
120i - $45,990
125i - $49,990
M140i - $59,990
Prices exclude on-road costs
Comfort Package - $2100 (118i, 118d, 120i, 125i)
Driver Assistance Package - $1800 (118i, 118d), $1400 (120i), $1000 (125i)
Innovations Package - $1800 (118i, 118d, 120i)