All else being the same, which grease consistency will flow better?

The chosen answer is NLGI 00 grease, which is correct because grease consistency is classified using the National Lubricating Grease Institute (NLGI) system, where lower numbers indicate softer, more fluid consistencies. NLGI 00 is much softer than higher numbers like NLGI 2 or NLGI 6, making it easier for this grease to flow under the same conditions.

When considering the grease consistencies, NLGI 00 will have a smoother, more liquid-like texture compared to NLGI 2, which, while still relatively soft, is significantly more viscous and resistant to flow. Additionally, NLGI 6, being much firmer, is designed for applications that require a thicker, more stable product, and as a result, it flows very poorly when compared to NLGI 00. ISO VG 100, while a measure of oil viscosity, does not align directly with the grease consistency classification and thus does not pertain to the flow characteristics of greases based on the NLGI scale.

In summary, NLGI 00 is the softest and most fluid choice among the options given, which facilitates better flow in comparison to the others.