In the very early stages of the program it was suggested that JLTV would replace the AM General High Mobility Multi-purpose Wheeled Vehicle (HMMWV) on a one-for-one basis.

However, most were unarmored and the type (including armored examples) incurred heavy losses when improvised explosive devices (IEDs) began being employed by insurgents.

To combat increasing numbers of IED attacks, the U.S. rapidly procured some 29,000 Mine Resistant Ambush Protected (MRAP) vehicles, including the Oshkosh M-ATV for use in Iraq and Afghanistan.

While MRAPs offered superior protection from IEDs, especially underbody blasts, they were significantly larger and heavier and had relatively poor off-road mobility.

The military incorporated MRAPs in response to operational needs, but never intended them to become a permanent part of their tactical wheeled vehicle fleets.

[16] In October 2008, the Pentagon narrowed the field of vendors to respondents Lockheed Martin, General Tactical Vehicles and BAE Systems/Navistar.

[21] In August 2012, the Army and Marine Corps selected the Oshkosh Defense L-ATV, Lockheed Martin JLTV, and AM General BRV-O, as the winners of the EMD phase.

In September 2013, full-pace, full-scope JLTV testing began at Aberdeen Proving Ground, Yuma, and Redstone Arsenal, Alabama.

[32] In June 2013, L-ATV prototypes participated in an event hosted by the U.S. JLTV Joint Program Office in Quantico, Virginia.

[35] In July 2014, Oshkosh announced the L-ATV had completed 200,000 miles (320,000 km) and all requirements for reliability, availability, maintainability (RAM) testing.

[36] In November 2014, Oshkosh announced the L-ATV had completed limited user testing (LUT) with the U.S. Army and Marine Corps for the JLTV EMD contract.

[40] potentially as a result of the release of JLTV testing data showing that the L-ATV lasted nearly six times longer between significant breakdown than Lockheed's vehicle.

[47] The total cost estimates include "research and development, procurement, military construction, and acquisition-related operations and maintenance" associated with a program, the Pentagon said.

[54] In early 2018 the Marines 2018 planning objective for JLTV was disclosed to be 9,091, although funding (as of April 2018) allowed for only 7,622 JLTVs through FY2023, with deliveries concluding the first quarter of FY 2025.

[55] For FY2020 the Pentagon's JLTV funding request totaled US$1.641 billion to procure 2,530 vehicles for the Army, 1,398 for the Marine Corps (with 3,986 more between FY2021 and FY2024), 140 for the Air Force, and 22 for the Navy.

[61] In July 2020, Oshkosh stated that over 7,500 JLTVs had been delivered to the U.S. Army, U.S. Marine Corps, U.S. Air Force, and U.S. Navy since the production contract was awarded in 2015.

The TAK-4i version fitted to the L-ATV remains undisclosed, but is not coil-sprung and is of the variable adjustable ride-height type with up to 20 inches (51 cm) of wheel travel, 25 percent more than the current standard.

[67][68][56] Motive power is provided by a digitally-controlled Gale Banks Engineering 866T V8 turbodiesel, based on the architecture of the General Motors Duramax L5P.

According to Oshkosh literature,[69] the ProPulse diesel-electric powertrain dramatically improves fuel economy by up to 35 percent in certain circumstances and serves as an on-board generator with enough output to power an entire airfield or hospital, generating up to 120 kW of AC power for external operations; the hybrid powertrain was not a requirement of the JLTV program.

[56] In a limited user test (LUT) c. 2016, the L-ATV demonstrated reliability of 7,051 "Mean Miles Between Operational Mission Failure", more than the Humvee and either other JLTV competitor.

During the L-ATV design process, every component was optimized for survivability, resulting in the same level of protection in a vehicle 30 percent smaller.

[76] The base L-ATV does not have a standard armament, however it can be fitted with a selection of weapons including light, medium, and heavy machine guns, automatic grenade launchers, or anti-tank guided missiles (ATGMs) depending on user requirements.

The JLTV family now consists of three base vehicle platforms, Utility (JLTV-UTL), Close Combat Weapons Carrier (JLTV-CCWC) and General Purpose (JLTV-GP).

Standard U.S. military M-designators are applied base vehicle platforms when outfitted to a specific Mission Package Configuration.

[6] In January 2022 Oshkosh unveiled a hybrid-electric Joint Light Tactical Vehicle (eJLTV) technology demonstrator that uses a ‘commercially available' lithium-ion battery.

The decision was taken to leverage the investment made in the HMMWV’s Light Tactical Trailer (LTT) and not to resource procurement of the JLTV-T. As a result of this, initial quantities were limited to test examples only.

[citation needed] In June 2020 Oshkosh announced that the company had been awarded a contract modification to increase available trailer options from 32 to 3,541.

The JLTV-T is based on a bolted channel section chassis and features independent trailing arm and air suspension.

The cargo deck features removable sidewalls and tailgate, an onboard stowage box included for these when the trailer is used as a flatbed.

At AUSA 2016, Oshkosh displayed a JLTV General Purpose variant equipped with an EOS R-400S-MK2 remote weapon system integrated with Orbital ATK's M230LF 30 mm lightweight automatic chain gun.