The Mercedes-Benz M104 is a group of inline-six engines from the 1990s, and they're an absolute tuner's dream. The powerplant is simple, yet durable, with the potential to produce over 1,000 horsepower with the right modifications, giving the iconic Toyota J2Z engine a run for its money.The 2JZ inline-six is one of the most famous car engines of all time. The widespread knowledge of this powerplant, and more importantly, its tuning potential, likely came in part from the first The Fast and the Furious movie, where Paul Walker's character puts $15,000 worth of upgrades into a completely junked Supra to make it faster than a Ferrari. This is certainly a cool scene, and one that would have looked a lot different if Brian O'Connor outran a Ferrari in a Mercedes E-Class wagon.This odd idea is actually plausible because both engines have immense tuning potential with the right characteristics to achieve four-digit power figures. Design Mercedes-BenzLike Toyota's 2JZ engine, the Mercedes-Benz M104 is an iron-block, aluminum-head straight-six engine. The German engine actually predates the Toyota by two years, with a production run from 1988 to 1999. It was available in 2.8-, 3.0-, and 3.2-liter displacements in the non-AMG models, with power ranging from 190 hp to 228 hp in the stock configurations. The engine is known to be a reliable and smooth powertrain in its stock configuration, mostly used in Mercedes' midsize models like the E-Class.Unlike the JZ, the M104 was never sold with a factory-fitted turbocharger, like on the fourth-gen Supra. It was the turbo that made the Supra so easy to tune. Many owners replaced the original twin-turbo setup with a single, larger one to increase the mill's power output significantly. Tuning Potential Mercedes-BenzThe M104 and 2JZ both share many design similarities, but one of the keys to both of these engines' potential is the heavy-duty iron block that can withstand being heavily modified. Just like the 2JZ, the easiest way to massively boost the M104's power is with a turbo kit, with some builds known to get over 1000 hp, as seen with YouTuber TurbobanditOfficial's 300E. Aside from the block, the standard engine has all the other components that are associated with a performance engine: dual overhead cams, four valves per cylinder, and electronic fuel injection are all elements that can be upgraded.Aside from adding a turbocharger, other common modifications, such as an upgraded exhaust and intake, can also help boost the power output. Upgraded pistons and head bolts are also common and will help the engine handle the higher power output. Of course, cooling such a powerful engine is key to keeping it running, so upgrading the radiator is a helpful improvement.Considering some models equipped with the M104 are relatively lightweight, the engine is a prime candidate for an awesome build. One non-engine component to consider is the brakes and tires, as these old Mercedes models weren't really meant to handle more than 230 hp, so wider tires and bigger brakes are actually a must to use the power. Wheels are important for aesthetic reasons, and none other than the iconic AMG mono blocks are a good fit for these 1990s Mercedes. Lack of Manuals. Mercedes-Benz When looking for one of these many 1990s Mercedes, you’d come to a quick realization that many of the models available in the US are mostly automatic. Unfortunately, manual transmissions weren’t a common option in Mercedes-Benz models, so to shift your own gears with one of these insane engines, it's likely you would need to do a conversion or import a European model where manuals were more common.Regardless of your car of choice, most 1990s Mercedes with the M104 engine offer a blend of style, build quality, and performance that can be picked up at a relatively low price. Models Bring a TrailerIf these performance figures tempt you, and you’re now considering a Mercedes equipped with the M104 engine, then choice is on your side. Mercedes fitted this engine in nearly every car in its lineup in the 1990s, including compact sedans like the first-generation Mercedes C-Class and large sedans like the 1991-1998 W140 S-Class.Midsize models, including the 1989-1995 (W124) and 1995-1997 (W210) E-Class, were available in multiple body styles: coupe, convertible, sedan, and wagon. This straight-six was also fitted to more niche cars like the SL-Class and even the G-Wagen, meaning there is plenty to choose from. AMG Models The MB MarketIn the 1990s, Mercedes was only beginning to launch its AMG division, and the result was some pretty rare AMG models that also used the M104 engine. The first of these is the 3.4 AMG made for the W124 E-Class between 1990 and 1992. Power was upped to a peak of 268 hp produced at 6,500 rpm. This engine was also fitted to a select few SL models.There was also the E36 AMG, where power increased to 276 hp and 284 lb-ft. This was the most powerful factory iteration of the M104 engine. In the American market, these models were slightly less powerful, producing 267 hp and 280 lb-ft. Non-Mercedes Applications. SsangYongThe weirdest use of M104 was by a Korean brand called SsangYong, which was never sold in North America. The brand installed this engine across its entire model range through the 2010s, including the Musso off-roader and the Chairman executive sedan. The downside of SsangYong models is their styling; some of these vehicles are among the ugliest cars made. Any of these would make an awesome sleeper car, as their looks do not match their engine's tuning potential. What To Buy? Mercedes-BenzIf what you desire is a small, cheap sedan that you can modify and toss around, the W202 C-Class and W210 E-Class are the best options. The M104 was on its way out when these models were released, and can only be found in the 1993 to 1997 C280 and the 1995 to 1997 E280. These models are fairly easy to find, and don’t hold much value on the second-hand market as they can be found for under $5,000 in decent condition.Another popular way to get the M104 is the iconic W124 300E made between 1989 and 1995. The design of this model aged very well, with the simple, boxy 1990s style the right combination of sportiness and sophistication. They have remained relatively affordable as they can be picked up for under $10,000.Mercedes-BenzThe alternative option to these two is the larger, heavier W140 S-Class. These are also relatively affordable as they can be picked up for under $15,000. However, the W140 S-Class is a more complex model with more electrical components that can go wrong, something buyers should be aware of. On the plus side, S320 models equipped with the M104 engine didn't have an air suspension, a component known to be relatively expensive to replace when it breaks.The SL300 also remains relatively affordable with prices sitting around $10,000, and is one of the models that can be easier to find with a manual transmission. Meanwhile, the G-Wagen remains an expensive option as even models from the 1990s can fetch upwards of $30,000.Mercedes-BenzThe AMG versions of the M104 are the most expensive on the second-hand market, as early AMGs have become very collectible over the years. This is especially true for the 300E 3.4 AMG, with one selling on Bring a Trailer for $115,500 in January 2026. Meanwhile, C36 AMG is comparatively easier to find, though still quite rare. This is one of the cheapest six-cylinder AMG models available on the second-hand market, as they can still be commonly found for under $20,000.