BMW freshens up the 1 Series with extensively modified front and rear end design, chassis and engine updates. It also takes one step towards the most likely future of the all-new 1 Series generation due in 2018 by adding downsized engines already in this iteration of the entry level BMW. Which feels as good as ever in the M135i top of the range fast and sharp “old school” six-cylinder pushed by the rear wheels.

The revamped 1 Series, which is still propelled via the rear axle or all wheel driven in the four and six-cylinder models, also adopts the engine/transmission assemblies of the recent 2 Series Active Tourer, i.e., the 1.5 three-cylinder units (both petrol and diesel) delivering the goodies to the rear wheels. While resource optimizing grounds strongly suggest the future all-new 1 Series will be based on the MINI/Active Tourer architecture, BMW technical executives assured us – during this test drive in Portugal – that both solutions (rear-wheel drive and front-wheel drive) are currently under evaluation and that no decision has been taken yet.

Nevertheless, this might well be the last (partially) new car launched in the compact segment that uses the services of a six-cylinder engine (on the unapologetic M135i) and rear wheel drive, a BMW longtime trademark. This, along with the fact that the only other engine available to drive in this first attempt in Southern Europe was the 2 liter diesel, made it easy to decide which of the 2015 1 Series we would get our hands on. But not yet.

A retouched designed kidney grille and larger air intakes help to emphasize the car’s dynamic potential. Look again and you will notice the flatter geometry headlights as well as LED daytime driving lights as standard (full-LED may now be specified as an option). At the same time, the 1 Series rear look was brought closer to the rest of the model range thanks to the completely remodeled rear lamp clusters which now display the characteristic “L” shape and also reveal LED-powered lights.

Access the mostly unchanged well-built driver oriented cockpit and you will also find a number of new additions mainly in the form of more standard content: automatic air conditioning, a rain sensor, the BMW Radio Professional and the iDrive operating system, complete with a high-resolution 6.5-inch display integrated in the instrument panel as a freestanding monitor. Other interesting upgrades on the standard content include the servotronic steering and the tire pressure indicator and among the optionals you will now find radar-based active cruise control with Start/Stop and the Advantage, Sport Line, Urban Line and M Sport packages available as an alternative to standard specification allow fresh and wider individualization.

As mentioned, the main technical evolution is the application of the three-cylinder blocks in the 1 Series, a modular family which uses the same technical base for both the diesel and the petrol engines (and also the same technology of the 4, 6 and 8 cylinder: Valvetronic admission (petrol), variable turbo (diesel), double VANOS distribution (petrol) and direct injection (with solenoid injectors and a 2000 bar injection pressure on the diesel units).

The six-cylinder 3.0 liter engine which equips the M135i is unique in this segment where more than four cylinder engines vanished from the face of the Earth and downsizing is key to improve fuel efficiency. And in BMW the odds are that it will also disappear when the next generation 1 Series is launched towards the end of this decade. One more reason to take fully advantage of it while it is around especially now that has been awarded an extra 5 hp, to a total of 326 hp and, perhaps even more relevant, the full availability of the 450 Nm from as low as 1300 rpm and all the way to 4500 rpm.

The unit we drove in Portugal was a rear wheel drive car (you can also have the xDrive) which stands from the rest of the model line-up thanks to the M aerodynamic package, which can be identified by features including extremely large outer air intakes in the front apron occupying the space normally reserved for fog lamps. The exterior mirror caps are in the typical BMW M Performance Automobile paint finish Ferric Grey, the rear apron of the comes with a distinctively styled diffuser in a Dark Shadow metallic paint finish and surrounds for the exhaust system’s twin tailpipes.

The exhaust system also gives clear visual and acoustic evidence that this is a special 1 Series thanks to the black chrome tailpipe embellishers and the resonant soundtrack. The same “special” feel can be sensed in the interior with sporty character touches like the door sill plates with “M135i” lettering, an M leather steering wheel, sports seats and interior trim strips with an M-specific design, the M gearshift lever or selector lever gaiter, the full leather handbrake lever grip, the anthracite-colored BMW Individual roof liner, the knee pad in the driver’s foot well, the M driver’s footrest and the lighting package.

Time to start the engine then. There was no chance to take the highly spirited M135i to a race track this time but speed limits in Portugal are rather flexible and the country roads on the test route quite empty, so the conditions to extract a good deal of the M135i juice were met (if anything we did not dare to give the day off to the ESP which we would have done on a controlled racing environment taking full advantage of this chance BMW engineers give you to raise adrenalin one step further). The six-speed manual gearbox pairs very well with this six-cylinder unit as the first three gears are noticeably shorter to leverage performances and although the eigh-speed ZF automatic counterpart works well it does not provide the same kind sheer driving pleasure.

The combination of rear wheel drive (and the wise tire choice, 225/40 R18 in the front and 245/35 R18 in the back), an even weight distribution front/rear, a low driving position and the precise and fast steering elevate the M135i to a path of handling excellence which its rivals from the premium German manufacturers simply cannot aspire. The Mercedes-Benz A45 AMG is very sharp, impressively fast (it offers an extra 44 hp) and deserves a thumbs up for handling competence but without the “ear-to-ear” smile factor only a front engine/rear propulsion duo in a compact sports cars is able to deliver.