 It spawned four variants through 1968, the final and largest being the 2.8 L M130.It was achieved by boring out and stroking the M180's original "over-square" bore × stroke of to , yielding a displacement of .Mercedes also unveiled at the 1951 Frankfurt Motor show a larger 3.0-litre M186 ‘big six’ inline-6 to power its new flagship 300 (W186) "Adenauer" four-door saloon.