SD60M
The Rail King freight cars based on modern prototypes are sub-scale cars. Besides being made 9 years apart the two cars you posted have different dimensions. The Rail King car measures 10 7/8" x 2 3/8" x 3 7/8" while the Premeir car is 12" x 2 3/4" x 4 3/16". Premier freight cars produced since about 2005 also have the newer type of MTH freight trucks and most have mounting pads on their underframes for Kadee couplers.
If you are looking for a scale ADM tank car you might be interested in the MTH funnel flow tank car. It is one of the very nicely detailed freight cars introduced to the Premier line since the mid 2000s. It measures 11" x 2 5/8" x 4". Note the thumbtackless couplers and brake hose detail on the new style Premier trucks.
MTH doesn't advertise their tank cars by length. Only Weaver does that to distinguish between their two otherwise identical generic modern tank cars.
If you are interested in learning more about O scale tank cars keep an eye on future installments of the O Scale Freight Car Guide.
https://ogrforum.com/t...le-freight-car-guide