Go back

Setting new standards in the 5m³ range

A new basic body, new motors meeting European and North American exhaust regulations, a lightweight version, with polyethylene gull-wing doors, and a wide range of options, including compressed air treatment and generators for simultaneous production of compressed air and electric power: the new Mobilair M55 and M59 portable compressors have it all. And thanks to the pXv control, large pressure ranges can be covered with one and the same system. With the pXy control, familiar from larger Mobilair models, the infinitely adjustable maximum pressure (p) directly influences the maximum flow rate (v). Thanks to this flexible control system, it is equally possible to operate a breaker at a maximum pressure of 7 bar or perform sandblasting work at 10 bar. The pressure setting using the time-tested Sigma Control Smart controller is easy and convenient – like the system start-up. Where the M55 and M59 differ is in the motors and the sales territories.


The M55 is powered by a Kubota motor that meets the EPA Tier 4 emissions standard for Canada and the USA. The M59 is powered by a Hatz motor that also meets the stringent EU Emissions Stage V standard. In addition, the European M59 is available in a version weighing less than 750 kg. That permits a chassis without a service brake. The driver does not need a special trailer licence and can select a smaller towing vehicle. And when the compressor arrives at the building site, it is easier to uncouple and manoeuvre by hand.

To compensate for the extra weight of the required diesel particulate filter while continuing to offer a portable compressor with an optional aftercooler and a large enough fuel tank for a full day's work onsite, Kaeser adopted a new approach to lightweight construction. Aluminium offers weight savings as compared with polyethylene with no loss of robustness or long-term value retention. Naturally the M59 is also available on request with a chassis fitted with an overrun brake. That is used, for example, when the user opts for a generator or compressed air treatment equipment with a filter combination for oil-free compressed air. For the first time, noise protection is handled by gull-wing doors made of rotation-moulded polyethylene. In both versions: two large gull-wing doors provide perfect access to all service locations.