Grumman LLV

The Grumman Long Life Vehicle (LLV) is an American light transport truck model designed as a mail truck for the United States Postal Service, which has been its primary user since it first entered service in 1986, 40 years ago. It was also used by Canada Post. The LLV uses a chassis built by General Motors based on its Chevrolet S-10 with an aluminum body built by Grumman.

In 2021, after a long competition, the USPS announced it had awarded a $6 billion contract to Oshkosh Defense to produce the Next Generation Delivery Vehicle, which will replace the LLV. In February 2023, the USPS announced the purchase of 9,250 each of stock Ford E-Transit vans and Stellantis gasoline-powered vans. As of May 2023, the first custom NGDVs were scheduled to enter service in June 2024, nine months after the original October 2023 target date.

History

In the United States, the Grumman LLV is the most common vehicle used by letter carriers for curbside and residential delivery of mail, replacing the previous standard letter-carrier vehicle, the Jeep DJ-5. Curbside delivery from a driver seated in a vehicle to a curbside mailbox is sometimes termed "mounted delivery", in contrast to walking delivery.

The Grumman LLV was the first vehicle specifically designed for the United States Postal Service (USPS); the USPS provided a specification and three teams created prototypes that were tested in Laredo, Texas, in 1985: Grumman in partnership with General Motors, Poveco (a joint venture of Fruehauf and General Automotive Corporation), and American Motors Corporation. The main design points of the vehicle in contract competition were serviceability, handling in confined areas, and overall economical operation. Prototypes were each subjected to a 24,000 mi (39,000 km) road test, including frequent starts and stops, gravel surfaces, cobblestones and potholes, hauling a payload of up to 2,000 lb (910 kg).

Previously, Grumman had built a limited number of KurbWatts, a battery electric vehicle with an aluminum delivery van body, which was tested by the USPS in the early 1980s. At about the same time, Grumman also built 500 KubVans, which used a similar lightweight aluminum delivery body on a Volkswagen Pickup diesel chassis (VW Caddy does not have a separate chassis; it was unibody) and also underwent testing by the USPS. These designs influenced Grumman's candidate body design for the LLV. Grumman won the competition and was awarded a $1.1 billion contract to produce 99,150 LLVs in April 1986; USPS also held an option for an additional 54,000 LLVs.

Production

The vehicles were assembled by the Allied Division of Grumman in Clinton Township in Lycoming County, Pennsylvania. The first vehicle was completed in April 1986. At peak production, 95 LLVs were completed each day, at a rate of approximately one every five minutes. Grumman invested $28 million into the factory, doubling its size to 213,000 ft² (19,800 m²) and increasing the workforce from 250 to 600.

The USPS purchased more than 100,000 of these vehicles, the last one in 1994. As its name suggests, the Grumman LLV is easily capable of a long life. The required lifespan specified by the U.S. Postal Service was 24 years, but in 2009, this was extended to 30 years. The Grumman LLV can easily last over 200,000 miles on its original engine and transmission before needing an overhaul.

The USPS acquired 21,000 Ford–Utilimaster FFVs in 2000 and 2001 to supplement the LLV fleet. The FFVs have a similar aluminum body and also are right-hand drive, but ride on a chassis built by Ford Motor Company with a body built by Utilimaster.

In 2010, approximately 140,000 LLVs remained in the USPS delivery fleet; retirement and attrition had reduced that to 126,000 by 2021. A number were also sold to Canada, Mexico, and several other countries.

Technical description

Like the older postal-service Jeep DJ-5, the Grumman LLV features a right-hand-drive (RHD) configuration, in contrast to the typical left-hand-drive (LHD) position of vehicles in North America. It also features a large metal tray, which is able to hold three trays of letter mail, mounted where a passenger seat would normally be. This arrangement positions the driver on the side of the vehicle closest to the curb, enabling the carrier to easily grab sorted mail and place it into mailboxes without having to leave the seat. Other notable features are an exceptionally tight turning radius and a low-geared, three-speed transmission for hauling heavy cargo. The LLV has a 1,000-pound (450 kg) cargo capacity, double what the Jeep DJ-5 could hold.

The body and final assembly is by Grumman, and the chassis is made by General Motors, based on the 1982 Chevrolet S-10 Blazer, powered by GM engines including the 2.5-liter inline-four TBI Iron Duke and, in later production, 2.2-liter inline-four SPFI LN2; the instrument cluster and front suspension are similar to those used in the Chevrolet S-10 pickup and S-10 Blazer sport utility vehicle.

The LLV has a unique footprint. The front wheels (taken from the two-wheel-drive S-10 Blazer model) have narrower spacing than the rear wheels (using the rear axle from the four-wheel-drive S-10 Blazer model). The front of the vehicle also has low ground clearance. While this has advantages, there are some trade offs. The vehicle was tested successfully in warmer climates, but when used in places with substantial snowfall, they became difficult to control and were poorly adapted to those conditions.

The Grumman LLV's estimated average combined EPA fuel economy is 17 miles per US gallon (13.8 L/100 km; 20.4 mpg_‑imp; 7.2 km/L) [16 / 18 mpg_‑US (14.7 / 13.1 L/100 km; 19.2 / 21.6 mpg_‑imp; 6.8 / 7.7 km/L) on the city/highway cycles, respectively]. In actual use by the USPS, which includes extensive stop-and-go driving for residential delivery, average fuel economy is about 8.2–10 mpg_‑US (28.7–23.5 L/100 km; 9.8–12.0 mpg_‑imp; 3.5–4.3 km/L).

Like other U.S. Postal Service vehicles before it, the Grumman LLV does not carry a license plate and instead uses a seven-digit U.S. Postal Service serial number. The first digit of the serial number represents the last digit of the year in which it was made, ranging from 7 (model year 1987) to 4 (model year 1994). The second and third digits are the vehicle type code, with the LLV's codes ranging from 19-31. The USPS does not permit reselling LLVs, so when they are retired, they are scrapped for parts and the decals are destroyed; however, at least one was sold by the State of Georgia at auction in 2013.

Commercial version

Grumman also planned to market a commercial variant of the LLV with right-hand drive as the CLLV through Chevrolet. The CLLV was essentially the same as the LLV, with the same chassis, built by GM at Moraine Assembly using S-10 components, driven by the 2.5L Iron Duke through a 3-speed automatic transmission and a 7-5⁄8" positraction rear differential with 3.42:1 final drive ratio. The CLLV was rated to carry a payload of 1,400 lb (640 kg), including the driver, and could accommodate up to 121 ft³ (3,400 L) of cargo.

Electric versions

Ten LLVs were converted in 1995, 1997, and 1999 for a pilot program, adding a battery electric drivetrain developed by GM Hughes and U.S. Electricar. They used lead-acid battery chemistry. The resulting Electric Long Life Vehicles (ELLVs) were deployed to post offices in Harbor City, California (in Los Angeles); Westminster, California; and Merrifield, Virginia. When GM canceled its electric vehicle program, the vehicles were taken out of service at the end of 2000.

At about the same time, Transport Canada commissioned Solectria Corporation in November 1998 to convert two LLVs to battery-electric; they were delivered to Canada Post in February 1999. The performance report, comparing the converted LLV to a conventional LLV, was published in February 2000. The Solectria/Grumman LLV was equipped with a 12-kilowatt-hour (43 MJ) lead-acid traction battery and 5-kilowatt (17,000 BTU/h) diesel-fired heater, giving it a nominal range of 30 km (19 mi). The traction motor was an AC induction type, with a peak output of 50 kW (67 hp; 68 PS) and continuous rated output of 20 kW (27 hp; 27 PS). Testing showed the typical consumption on a postal driving cycle was 19.74 kWh/100 km (106.1 mpg‑e) at an ambient temperature of −20 °C (−4 °F), giving a range of 27.39 km (17.02 mi); these figures improved to 16.04 kWh/100 km (130.6 mpg‑e) consumption and 29.58 km (18.38 mi) range at 20 °C (68 °F). By comparison, the conventionally-powered LLV on the same driving cycle returned fuel consumption of 0.22 L/km (11 mpg_‑US) at −20 °C (−4 °F) and 0.16 L/km (15 mpg_‑US) at 20 °C (68 °F).