The main difference between the 325i and the 328i is that the 328i has a more powerful engine.
BMW 3 Series Overview
The BMW 3 Series is probably BMW’s best-known model, as well as one of its most popular models; the 3 Series alone makes up nearly a third of BMW’s annual sales. The first generation of the 3 Series debuted in 1975 with the E21 3 Series, although it wasn’t until 1982 when the 3 Series took off thanks to the E30 generation.
The 3 series is heavily associated with having an inline-6; at least one trim level of every generation of the 3 Series came with an inline-6, and the E36, E46, and F30 generations of the M3 have all used an inline-6. The upcoming G20 M3 will likely use an inline-6 as well.
BMW’s method of naming their cars is semi-straightforward. In general, it works like this; the number represents both the specific model of the car and the displacement of the engine (for example, 325 means the car is a 3 Series, with a 2.5-liter engine).
The letter or letters after the numbers refer to further characteristics of the car. “i” means the car is fuel injected (which isn’t a big deal now but was back in the first generation of the 3 Series; not all of their cars came with fuel injection). Occasionally, BMW uses other letters in their model names, like “x” for all-wheel drive cars, “d” for diesel cars, and “s” for coupes.
Unfortunately, you can’t always trust BMW’s naming scheme these days. For example, the E90 325i comes with a 3.0-liter inline 6, as does the 328i from the same generation.
Plus, nowadays you have cars like the M340i which not only doesn’t have a 4.0-liter engine but also isn’t technically an “M” car; the M340i is an “M Performance” model that comes with a bunch of extra performance features but isn’t built by BMW’s M division.
Comparing the 325i and 328i
The 325i and 328i were sold at the same time throughout three generations of the 3 Series, those being the E36, E46, and E90 generations. In all of the generations they were sold together in, the 325i and 328i were only one trim level apart from each other in the hierarchy.
Both the 325i and the 328i use an inline-6 although, in the E36 and E46 generations, the 325i used a 2.5-liter engine while the 328i used a 2.8-liter. For the E90 generation, however, both cars used the same 3.0-liter engine, although the engine in the 325i was detuned.
Here’s the comparison in power figures for the three generations of these trim levels:
- E36: 325i-189 hp and 181 lb-ft, 328i-190 hp and 207 lb-ft
- E46: 325i-184 hp and 175 lb-ft, 328i-190 hp and 207 lb-ft
- E90: 325i-215 hp and 199 lb-ft, 328i-231 hp and 200 lb-ft
While the 328i was consistently the more powerful version throughout the years, the power increases that the 328i offered were overall relatively small compared to the 325i, especially in the E36 and E46 generations. However, drivers who have tested out the E90 325i and 328i found that the 328i felt noticeably quicker.
Other than the difference in power and torque, the 325i and the 328i are more or less the same cars. In terms of items like exterior trim pieces and interior features, the two models are almost identical.
Small changes between the two include the wheel design, the finish on the exhaust pipe (the 325i has a black finish while the 328i has a chrome finish), and the steering wheel in the 328i features some silver-colored trim.
The main advantage of the 325i is that, because it is the lower-performance version, you can probably find a used 325i for less money than a used 328i with the same mileage.On the other hand, the E36, E46, and E90 generations are all fairly old at this point, so a decent 328i may not cost you that much anyway these days.
When choosing between a 325i and a 328i, the only real question is what performance level you’re looking for. If you need a faster car, there’s no question about it; you should go for the 328i. Both the 325i and the 328i also came with pretty much the same features across the board, so aside from the potential to get it for a lower price, there’s no reason why you should choose a 325i over a 328i.
That being said, the 325i is still a great car in its own right, and if you can’t find a decent 328i for sale but you do find a good 325i, rest assured you won’t be compromising too much.