The adoption of natural gas/hydrogen mixes represents a major step forward in identifying sustainable mobility solutions. Adopting technologies developed on a large scale for natural gas applications, it promotes a significant reduction in emissions of CO2  and hydrocarbons, carbon monoxide and nitrogen oxides, thus paving the way to broader use of of hydrogen in the transport sector in relatively short times. 2009 marked the completion of development activities for setting up the experimental fleet for the Regione Lombardia, consisting of 20 Fiat Panda cars (Natural Power based) fuelled with a mix consisting of 70% natural gas and 30% hydrogen in volume. Following tuning of the engine control system and adaptation of the materials of components in contact with the mix, the cars were tested (emissions, fire) and registered according to the single model procedure. The first fleet of 10 cars was delivered to the Regione Lombardia which has initiated experimentation activities also thanks to two distributors set up (within the same project) by ENI and SAPIO at the Assago and Monza sites where the mixes will be made available in variable percentages up to a maximum of 30% in volume of hydrogen. A dedicated data acquisition system on each vehicle will make it possible to collect all the information necessary for monitoring correct functioning of the cars and for determining consumption and CO2. The data will be transmitted and made available on an off-board station at CRF and will provide an important database for assessment of the environmental impact and energy balance of the supply chain in effective conditions of use on the road. The Regione Lombardia has participated with the mix-type Panda in the opening ceremony of the world convention on the climate in Copenhagen during which the most advanced technological proposals intended to meet the need to reduce environmental impact in the transport sector paraded on the bridge between Denmark and Sweden.