The MD-81 (originally known as the DC-9 Super 81 or DC-9-81) was the first production model of the MD-80, and apart from the MD-87, the differences between the various long-body MD-80 variants are relatively minor.
The four long-body models (MD-81, MD-82, MD-83, and MD-88) only differ from each other in having different engine variants, fuel capacities, and weights.
The MD-88 and later-build versions of the other models have more up-to-date flight decks featuring for example EFIS.

Performance: Standard maximum take-off weight (MTOW) on the MD-81 is 140,000 lb (63,500 kg) with the option to increase to 142,000 lb (64,400 kg).
Fuel capacity is 5,840 US gallons (22,100 L), and typical range, with 155 passengers, is 1,565 nmi.
The MD-81 (originally known as the DC-9 Super 81 or DC-9-81) was the first production model of the MD-80, and apart from the MD-87, the differences between the various long-body MD-80 variants are relatively minor. The four long-body models (MD-81, MD-82, MD-83, and MD-88) only differ from each other in having different engine variants, fuel capacities, and weights. The MD-88 and later-build versions of the other models have more up-to-date flight decks featuring for example EFIS.
Performance: Standard maximum take-off weight (MTOW) on the MD-81 is 140,000 lb (63,500 kg) with the option to increase to 142,000 lb (64,400 kg). Fuel capacity is 5,840 US gallons (22,100 L), and typical range, with 155 passengers, is 1,565 nmi.
McDonnell Douglas MD-80