In 2025, BMW offers an impressive and diverse list of available vehicles for purchase, including 12 different SUVs, 12 different sedans, and a wide range of options in between. Yet, if we take a step back to the 1990s, there were only five distinct BMW models available on the market: the 3-Series, 5-Series, 7-Series, 8-Series, and the Z-cars (along with the M variants). This begs the question, which 35-year-old BMW models are the most reliable of that exclusive bunch?
Well, if you like to avoid nightmares and financial disasters, the general rule of thumb is never buy a used 1990s BMW 7-Series (or 8-Series). The 3-Series, 5-Series, and Z-cars are comparatively the most reliable BMWs of this era. If you have a 1990s BMW that is still running strong even today, it most likely is one of these models. Let’s break down the differences between each of these models and determine which 1990s BMW is worth it for you.
Early 90s: BMW E30 3-Series & BMW E34 5-Series
One of the most recognizable BMW models of all time is the BMW E30 3-Series, which was available from 1984 to 1991 in North America. Among the E30 generation, the best and most reliable models were the 325i (1987-1991) and the 325e (1984-1988). There were some four-cylinder variants available as well (318i), as well as an AWD variant (325ix), but trust us, you’ll want to avoid those. Thus, let’s break down the differences between the two most desirable E30 models (besides the M variants).
BMW E30 325i
A large part of why the BMW E30 is still sought after as a classic BMW to this day is the 2.5-liter M20B25 inline-six found at the helm of the 325i model. With 169 horsepower and 164 pound-feet of torque, the 2.5-liter inline-six provides respectable power output even today. Yet, it is not just about how much power, but rather, how it is presented.
The torque band is flat and full across the rev range, and this engine will happily sing a smooth and fulfilling song to its 6,500 RPM redline. Although not the most robust and reliable BMW inline-six of the 1990s, the M20’s simple, repair-friendly design helps keep more early-90s BMWs on the road, even today.
BMW E30 325e
Available during the same period as the E30 325i, the economy-focused 325e variant featured a larger displacement 2.7-liter version of the M20 inline-six, dubbed the M20B27. This larger engine was geared toward the American market that rewards low-end torque rather than peak horsepower, and as a result, produces 170 pound-feet of torque at 3,200 RPM (as opposed to the 325i’s 164 pound-feet of torque at 4,300 RPM).
The M20B27 inline-six is considered more reliable than the M20B25 because it is more of a workhorse than a performance engine, as it offers a significantly reduced redline (4,800 RPM pre-1987, 5,200 RPM post-1987). Despite the benefits of more torque, better fuel economy, and more reliability, many E30 owners still prefer the more fulfilling experience of the 325i. The 325i is already cutting it with being pretty slow by modern standards, so the 325e feels downright lethargic.
BMW E34 525i
The E34 BMW 5-Series is known as one of the most well-built BMWs ever built, and this 5-Series offered a surprising number of diverse engine configurations in its heyday. Of all the available engines, the most reliable is the M50B25TU inline-six found in the 1992-1996 E34 525i. The mid-range 525i model was not the sportiest variant, but its smooth straight-six engine proved the best performance-to-cost ratio.
BMW E34 540i
While the older architecture M30 inline-six found in the 535i model offers an impressive performance bump compared to the 525i, it was the M60 V-8-powered 530i and 540i models that took non-M 5-Series performance to unprecedented levels. The E34 540i variant, introduced in 1992, offered nearly 300 horsepower and 300 pound-feet of torque from BMW’s first update of their first modern V-8 engine, the 4-liter M60B40. Despite its amazing capability and buttery smooth responsiveness, the M60 (along with many other BMW engines of this era) was plagued by the Nikasil coating fiasco.
Mid-To-Late 90s: BMW E36 3-Series & BMW E39 5-Series
After the E30 generation came the E36 3-Series, which was available from model years 1992 to 1999. Of the available non-M E36 models, the most desirable variants are the inline-six-powered 325i and 328i. While the cute 318ti compact variant may seem like a cool, viable option, we’d say it’s best to avoid it and its underwhelming inline-four unit.
BMW E36 325i
The 325i variant of the E36 3-Series, powered by the DOHC M50B25 inline-six, was a big step up from the previous generation’s SOHC M20 inline-six. Despite sharing the same architecture (aluminum head and cast iron block) as the M20, the later M50B25TU variant would usher in a new era of technology as the first BMW engine offering VANOS, BMW’s variable valve timing system.
With 189 horsepower and 181 pound-feet of torque, the M50B25 inline-six-powered 325i feels a lot faster than the previous-generation 325i, despite the on-paper figures not looking massively different. The M50B25TU would debut in 1992 with the introduction of VANOS, making peak torque available 500 RPM sooner (4,200 RPM as opposed to 4,700 RPM). The M50 inline-six is known to be dead reliable compared to the M20, as it has a larger parts availability and is often easier and less expensive to fix.
BMW E36 328i
For the 1995 model year, the M50 inline-six was phased out and replaced by the M52 inline-six found in the 328i variant of the E36 generation. The M52 saw a significant shift from the use of traditional cast-iron block construction to the current modern standard of aluminum (although only the Z3 Coupe/Roadster would receive the aluminum block during this generation).
With 190 horsepower and 207 pound-feet of torque at 3,950 RPM, this was the first time a non-M BMW inline-six would boast over 200 pound-feet of torque (while also offering the lowest peak torque RPM we’d seen so far at 3,950 RPM). Despite its tendency to consume oil (like many old German engines), the BMW M52 inline-six is still one of the most reliable inline-six engines ever produced, with impressive output and low upkeep cost.
BMW E39 528i
While the E36 328i and the E39 528i 5-Series shared the same M52B28 in the early years of their production, in 1998, the E39 received the M52TUB28. The TU variant introduced double VANOS, further improving peak low-end torque by about 500 RPM down to 3,500 RPM. Considering that this same double VANOS system is still in use today, these late-model 528i variants are the most robust E39 5-Series models you can find.
BMW E39 540i
For the E39 generation of the 5-Series, the updated M62 V-8 replaced the M60 V-8 engine with increasing displacement in models such as the 535i and 540i. The largest differentiating factor between these two BMW V-8 engines is that the M62 utilized Alusil coating as opposed to Nikasil coating. By March 1997, all M62 V-8 engines utilized Alusil (tin-plating), phasing out Nikasil (iron-coating) for good. While this all sounds great, Alusil was by no means a foolproof solution and came with complications of its own. Unless you crave raw performance before anything else, it is best to avoid V-8-powered BMW models from this era (or any era, really).
BMW Z3 Coupe/Roadster
The last and most reliable 90s BMWs that you are likely to still spot occasionally on the road are the E36/7 BMW Z3 Roadster and E36/8 BMW Z3 Coupe. Based on the E36 compact platform, the first-ever Z3 model shares the same semi-trailing arm suspension from the previous generation E30 3-Series, giving the BMW sports car an oversteer bias (aka more fun).
BMW Z3 1.9 Coupe/Roadster
If you are going to buy a BMW four-cylinder engine from this era, the BMW Z3 chassis is the only place where this small engine feels at home. BMW Z3 production spanned from 1996 to 2002, and at launch, the 1.9 four-cylinder model was the only variant available. Because of the lightweight and sporty nature of the Z3, the inline-four feels great, but doesn’t have the desired qualities of being a dead reliable engine, nor is its efficiency noteworthy.
BMW Z3 2.8 Coupe/Roadster
Once the 2.8-liter M52B28 inline-six-powered 2.8 Z3 model debuted in 1997, it immediately became the most desirable non-M Z3 variant available. Not only that, but the M50, M52, and M54 inline-six engines would prove to be among the robust power units of the entire era, especially when considering their overall performance. At this point, in 2025, these platforms have been sorted out, and everyone knows about the major issues and how to address them.
As we mentioned, the M52B28 found in the Z3 2.8 model was the only U.S.-spec model that received the aluminum block (which means it was Nikasil coated). However, beginning in the 1999 model year, Z3 2.8 models offered the M52TUB28 inline-six, which utilized steel cylinder liners as opposed to Nikasil coating. If we were going to buy a Z3 2.8, we’d look for 1999 model year cars and newer to avoid any Nikasil-related issues.