The Grumman LLV has a top speed of 55 miles per hour.
The LLV, or Long Life Vehicle, was designed specifically for the United States Postal Service rather than for highway performance. Its priorities were durability, a tight turning radius, easy curbside access, and economical operation during repeated neighborhood stops. Its three-speed automatic transmission and truck-based construction favored steady delivery work over speed.
The 55-mph figure is commonly given as the vehicle’s maximum road speed. It also fits the Postal Service’s demanding prototype testing: LLV candidates had to drive 5,760 miles on a paved loop at speeds of 50 to 55 mph. That test speed should not be confused with a promise that every aging LLV can comfortably reach it in service.
Real-world performance varied with mechanical condition, load, terrain, and weather. The LLV’s narrow front track, rear-wheel drive, limited climate control, and aging components could make faster driving uncomfortable or unsafe. Thus, 55 mph is the standard specification answer, not a recommendation for postal routes.