On-desire AWD systems generate the secondary axle by using an Lively or passive coupling system or "by an independently powered drive system". The normal notes that occasionally, the secondary push technique can also provide the main vehicle propulsion. An example is a hybrid AWD motor vehicle wherever the key axle https://groupak.gr/%CE%B1%CE%BE%CE%B5%CF%83%CE%BF%CF%85%CE%AC%CF%81-4%CF%874