Does YJ Stand For Anything On A Jeep? Understanding The Company's Model Codes

Jeep has long been among some of the most influential car brands in the U.S. Having a legacy since the 1940s, it's no wonder the manufacturer is nationally recognized, particularly for producing some of the finest off-road vehicles available today. Jeep has had a long, storied history, which has shaped the company through and through. Many of its fans know the ins and outs of the company, including its penchant for model codes. 

Jeep started using model codes in the 20th century during World War II as internal identifiers for the different models of Jeep it made. At the time of their conception, these codes were used to group vehicle designs, but as the decades went on and Jeep announced the YJ, its two-digit codes would be more than an internal design identifier for the manufacturer; they would also be a way for its fans to track the model generations and designs. 

The Jeep Brand has its vehicles under a number of groupings, such as the Cherokee, Grand Cherokee, and Wrangler, the latter of which forms the umbrella under which the YJ falls. The Wrangler line has been around for a while, with several entries that have defined what modern off-roading is. The YJ stands proudly among the best, and this is because of a few key factors. 

The YJ debuted in 1987, bringing with it the Wrangler name that exists today. Jeep's CJ models, which had been around since 1945, were finally being phased out. Over the decades, the CJ had won over many car enthusiasts, and people were eager to see how the new entry would compare. The YJ was a standout from the get-go, with features like its rectangular headlights that set it apart from the rest of Jeep's lineup. As the CJ's successor, it had a few similarities with the vehicle, such as its solid axles and open-body profile. The first iterations of the YJ also used engines from the CJ series, further cementing it as the CJ's successor. As the first Wrangler, the YJ had a lot going for it, like its modernized interior and wider track. 

With the YJ, Jeep showed the automotive industry what it was capable of. The Jeep name had become synonymous with adventure and freedom, attributes that the YJ effortlessly upheld. But with such success came the inevitable question: How would the rest of the Wranglers perform? The next Wrangler was the TJ, which debuted in 1997, only two years after Jeep stopped producing the YJ. The TJ came with circular headlights, a return to form for the vehicle manufacturer. The vehicle boasted an updated coil spring suspension, which made it a delight to drive both on and off-road.

Two years before the end of the TJ's run in 2006, Jeep released the LJ, also known as the TJ Unlimited. The LJ was essentially a version of the TJ with a longer wheelbase, which provided more space – 13 additional inches of storage space and two extra inches of legroom, to be exact. Both the TJ and LJ ceased production in 2006. However, that same year, Jeep debuted the JK, which would reign until 2018. The JKU, which was basically a four-door Unlimited variant of the JK, would also be released and see continued production until 2018. 

In 2017, Jeep would announce the current Wrangler, the JL, which it would release in 2018. Jeeps have always had some powerful engine under their hoods, like the 2.5-liter four-cylinder motor, which could last more than 200,000 miles. With the JL, Jeep offers a turbocharged four-cylinder or an EcoDiesel engine. There's also a plug-in option if you settle for the Wrangler 4xe. Of course, while the JL marks the end of the Wrangler list, it only scratches the surface of two-digit Jeep codes out there. 

Jeep's Cherokee models are the company's small crossover SUVs. The Grand Cherokee also falls under Jeep's SUV umbrella, although it offers midsize SUVs that can be considered more luxurious than the Cherokee models. The Cherokee was the first of the two, debuting in 1974 with the SJ, which would see production until 1983. On the other hand, the Grand Cherokee's first generation, the ZJ, was released in 1992, and its production run lasted six years.

The XJ was the second Cherokee entry, released from 1984 to 2001, while the WJ was the second Grand Cherokee, released between 1999 and 2004. The last model in the Cherokee lineup is the KL, which has been around since 2014, only ending its production in 2023. While the Cherokee did receive a third-generation entry in the name of the KJ between 2002 and 2013, Jeep eventually changed the vehicle's name to the Liberty in the U.S. (The Liberty would have two generations under its name: the KJ and KK). 

With the Grand Cherokee, Jeep released the WK between 2005 and 2007. This vehicle marked the Grand Cherokee's third generation and received a facelift in 2008, extending production to 2010. This WK came with a number of engine options, including a 5.7-liter V8 Hemi and a multi-displacement 4.7-liter V8 gas engine. In 2011, Jeep released the WK2, which continued production until 2013 before receiving a facelift in 2014 that lasted until 2016, when Jeep granted it yet another facelift. With the second facelift, the WK2 continued until 2021 before welcoming the current Grand Cherokee, the WL. The Cherokee, Grand Cherokee, and Wrangler hold the title for most generations in Jeep's catalog. However, there are a few more models that carry Jeep's famed codes.

The following entries in Jeep's lineup do not have as many generations as the aforementioned ones. Yet, they carry the two-digit codes Jeep is well known for. They include the Jeep Gladiator, Compass, Renegade, Wagoneer, Commander, and Avenger. To start, the Gladiator had the Gladiator JT, which debuted in 2019 and is still in production today. The 2025 variant of this vehicle comes equipped with a 3.6-liter V-6 that pushes out 285 horsepower. 

For the Jeep Compass, two generations exist. These include the MK, which was released between 2007 and 2017, and the MP, which continued the MK's reign from 2017 and is still in production. The initial MK base model came with a 2.0-liter four-cylinder engine that produced 158 horsepower, while the 2017 MP came with a 2.4-liter four-cylinder engine that produced 180 horsepower. 

The first generation of the Jeep Wagoneer, the SJ, was released in 1963. It had an impressive 29-year run before ending production in 1991. In 2021, Jeep reintroduced the Wagoneer under the WS model code, offering a Wagoneer and Grand Wagoneer option. As for the Jeep Renegade, only a single model code, the BU, exists. The BU debuted in 2015 and is a subcompact SUV that can comfortably traverse off-road terrain.

The Jeep Avenger, which only has one model code, the JJ, was released in 2023. An electric SUV, the Avenger JJ, comes with up to 248 miles of electric range. Finally, the Jeep Commander has three generations: the XK, WK2, and H1/H6. Jeep released the  XK between 2006 and 2010, the WK2 between 2018 and 2022, and H1/H6, which is still in production, in 2021.