UFI MULTITUBE technology for the Alfa 33 Stradale

Alfa Romeo chooses UFI MULTITUBE, the revolutionary engine air filter technology, for the exclusive Alfa 33 Stradale limited edition.

Alfa Romeo, the historic brand now part of the Stellantis Group, has chosen UFI MULTITUBE, the revolutionary engine air filter technology from UFI Filters, for the 33 Stradale supercar.

With the 33 Stradale, Alfa Romeo returns, after a long period of absence, to the segment of exclusive ultra-high performance cars.

Scheduled to produce only 33 examples, all of which have already been sold despite its price tag of over a million euros, the unreleased Biscione coupé is clearly inspired by the 1967 version of the same name, considered one of the most beautiful cars of all time.

From the 33 2-litre of the 1960s, created at the time by designer Franco Scaglione and closely related to its competition version, the new millennium interpretation takes up above all the V shape that characterises the front bonnet, completed by the classic Alfa Romeo badge.

Inspired by that of its glorious ancestor is also the characteristic vertical opening – known as the ‘elitra’ – of the doors.


Built around a carbon-fibre monocoque, the 33 Stradale has excellent construction characteristics. But the heart of an Alfa Romeo is, traditionally, its engine, and in this, too, the 33 Stradale of the new millennium (although also available with all-electric propulsion) is equal to its ancestor, which mounted a two-litre V8 derived from the competition one.

Now the choice has fallen on a V6 with a three-litre cubic capacity, installed in a mid-longitudinal position and equipped with sophisticated solutions, such as the innovative pre-chamber combustion system with twin spark plugs, dual direct and indirect injection systems and turbocharging via two turbochargers.

Thanks to these and other devices, the engine delivers 620 hp, enabling the 33 Stradale to reach a top speed of 333 km/h and accelerate from 0 to 100 km/h in less than three seconds.


Contributing to the achievement of this performance is the airbox, engineered by UFI Filters technicians and based on MULTITUBE technology: the latter consists of a revolutionary engine air filtration solution that employs a patented tubular structure, capable of replacing the traditional panel filter.

The special tubular formula of the filter media, made from 100% hydrophobic synthetic fibres, maintains full functionality and filtration performance (over 99.5%) throughout its entire life cycle.

Peculiar features of MULTITUBE technology are its geometric flexibility and filter resizing. Thanks to the first of these features, the cartridge structure can provide for the positioning of the tubes in parallel, in series or according to different geometries, with different diameters and lengths, depending on the space requirements of the engine.

This allows the UFI Group to offer manufacturers specific designs for the needs of each model, optimising their placement within the engine compartment. But MULTITUBE‘s innovation also makes it possible to contain the size of the filter, occupying – depending on the application – a space reduced by up to 50% compared to a traditional panel system, without affecting its filtration capacity in the slightest. The consequent reduction in the weight of the filter, which can be as much as 25%, is even more important for cars dedicated to absolute performance such as the 33 Stradale, for which reducing weight as much as possible is essential.

Finally, the geometric shapes of the UFI MULTITUBE filter make it possible to achieve better airflow dynamics: their linear passage through the structure decreases the car’s drag and minimises pressure and energy loss, ensuring greater power availability (measured in certified tests with an increase of up to 4% for some vehicles) and a reduction in fuel consumption and polluting emissions.

Not least the unsurpassed flame resistance, UFI MULTITUBE has passed the DIN53438 test – ISO standard – which determines the degree of combustion of commercial materials, receiving an F1 classification, the highest possible.