The gang operated in Ranhola, Aman Vihar, Subhash Place, Bhalswa Dairy, Sultanpuri, Nangloi, Moti Nagar and Shastri Nagar, the police said.
Explaining their modus operandi, the police said the suspects would board an auto rickshaw but get down of the vehicle after a few metres to buy a soft drink.
They would then spike the drink and offer it to the rickshaw driver and when the driver loses consciousness, they would flee with the vehicle, it said.
The four were arrested near Karala Water Tank in outer Delhi when they were travelling in an auto rickshaw, they said.
Deputy Commissioner of Police (Outer) Pankaj Singh said they have been identified as Parveen alias Shanky, Suraj alias Lovely, Prakash and Avdesh alias Kale.
All are aged between 24 and 36.