$re = '/(\d+(?:,\d+)?\s*l/\d+km).*?(\d+\s?g\s*CO[₂2]/km)/m';
$str = '17.160 km, 80 kW (109 PS)Limousine, Autogas (LPG), Automatik, HU Neu, 2/3 Türenca. 5,0 l/100km (komb.), ca. 116 g CO₂/km (komb.)
EZ 10/2018, 12.900 km, 80 kW (109 PS)Limousine, Unfallfrei, Hybrid (Benzin/Elektro), Halbautomatik, HU Neu, ca. 5,9 l/100km (komb.), ca. 134 g CO₂/km (komb.) ... and so on';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php