Successful ‘sixes’
BMW is intrinsically linked to the straight-six engine layout, though it has not always had cars powered by this design.
However, many of BMW’s most iconic models are powered by a straight-six motor, from swift M cars to luxury saloons.
The straight-six has also helped BMW dominate in sectors as diverse as sporting roadsters and luxury SUVs, proving that this engine configuration has served the German car maker superbly.
Here’s our list of six-cylinder BMW models, presented in chronological order.
1. 1933 BMW 303
The 303 was BMW’s first six-cylinder-powered car and arrived in 1933 to give Germany’s expanding middle class a vehicle they could aspire to.
It might have had a mere 1173cc capacity, but the straight-six unit came with two side-mounted carburettors, and it was notable for its smoothness and excellent torque.
To begin with, the 303 had a modest top speed of 55mph, but the 315 that developed from the original model was the first BMW to break the 100kph (62mph) barrier. Thanks to its 1490cc six-cylinder motor, this new-for-1934 model was well suited to the autobahn.
The 303 was also the first to come with the distinctive ‘Nieren’ kidney grilles that have become an identifying feature of all BMWs since.
2. 1935 BMW 319
In many respects much the same as the 315, this BMW model arrived in 1935 with a larger, 1911cc, straight-six engine.
The twin-carburettor version was known as the Type 45 due to its 45bhp output, or BMW could offer keen drivers the triple-carb Type 55 version with, you’ve guessed it, 55bhp.
Customers could order the 319 with tourer, saloon, cabriolet and drophead coupé bodywork, or there was the spin-off 319/1 two-seater sports model.
The 319/1 was capable of more than 80mph. BMW produced around 100 of this model, as well as 200 of the 315/1 that used the same body but with the smaller, 1490cc, straight-six engine.
3. 1936 BMW 326
The BMW 326 was very much the company’s 5 Series of the pre-war period with its elegant, four-door saloon bodywork and strong, six-cylinder engine.
The now-familiar 1971cc, overhead-valve ‘six’ produced 50bhp, which was sufficient to power the saloon to 71mph.
It was also capable of covering up to 300 miles on a single tank of fuel, reflecting the longer distances now possible on Germany’s autobahnen.
Two- and four-door convertible versions of the 326 were also offered, and the model notched up an impressive 15,949 sales when production ended in 1941.
4. 1936 BMW 328
Easily the most recognisable pre-war six-cylinder BMW, the hugely influential 328 took the company’s 1971cc straight-six and made the most of it.
Power for the 328 was 79bhp in standard form, aided by three carburettors and a new aluminium cylinder head.
In this form, the two-seat sports car was able to nudge 100mph flat out and offer 0-50mph in just 7 secs.
Racing versions with less weight, streamlined bodywork and up to 130bhp were impressive in competition.
It’s thought BMW built 461 of its 328, including 48 badged as Frazer Nash-BMWs sold in the UK from 1937-’39.
5. 1936 BMW 329
With its 329 badge, it was fair to assume this BMW would have been fitted with the more powerful, 1971cc straight-six.
However, BMW recycled its less powerful, 1911cc, six-cylinder motor into these two- and four-seat convertible cars.
Shorter and lighter than the 326 with which it shared some components, though the chassis and engine were lifted from the 319, the 329 was something of a parts-bin concoction. Even the body was based on a design from Daimler-Benz.
The two-seater Drauz Convertible was a much better looking car than the four-seater, and the pair managed total combined sales of 1179 units by the time they were replaced by the 320 in 1937.
6. 1937 BMW 320
The 320 badge has become a staple of BMW’s line-up and the first to sport this famous number arrived in 1937 as a replacement for the 319.
Like its predecessor, the 320 came with a straight-six unit, but capacity was increased to 1971cc thanks to a larger bore that helped raise power to 45bhp.
There was a choice of two-door saloon or convertible bodies to begin with, added to by a four-seat convertible bodied by Reutter in early 1938.
Although not a technically advanced car or particularly dynamic to drive, the 320 was a steady seller for BMW and found 4185 buyers, plus a further 3697 customers for the updated 321 version of 1939.
7. 1937 BMW 327
Where the BMW 328 was an out-and-out sports car, the 327 took the same potent 79bhp 1971cc straight-six and put it in an elegant 2+2 convertible.
There was also a lower-powered version of the 327 Sports Convertible with a higher-compression version of the 326’s ‘six’.
However, it was the 79bhp model that appealed most to wealthy drivers, who appreciated its 90mph top speed and its all-synchromesh, four-speed manual transmission.
BMW added a Sports Coupé version in 1938. A total of 1965 of these sophisticated cars were produced.
8. 1938 BMW 325 Kübelwagen
The basic body and chassis of this army reconnaissance vehicle was a standardised design intended to be built by a variety of German car makers.
However, standardisation went out of the window when each fitted their own engines to this four-wheel-drive, off-road vehicle.
BMW’s choice was a 1957cc straight-six, which was powerful enough to see the hefty Kübelwagen up to 50mph.
The 1.8-ton weight hindered the Kübelwagen when driving off-road and the complexity of its four-wheel-drive system also limited its usefulness.
9. 1939 BMW 335
The BMW 335 took the earlier 326’s body and stretched it by 23cm (9in) to create a large luxury saloon. With that increase in size came more weight, which necessitated a large engine to cope.
BMW came up with an all-new, 3485cc, straight-six motor producing 89bhp at 3500rpm. This offered easy cruising at 75mph and a top speed of 90mph.
The final series production model launched by BMW prior to the outbreak of the Second World War, the 335 was offered as a saloon and two- or four-door convertible.
Given its luxury, cabin space and power, many 335s were used as German army staff cars. Most led a hard life and consequently few of the 410 built survived.
10. 1951 BMW 501
BMW was unable to produce any cars after the Second World War until 1951, though some vehicles badged as EMWs had been built based on the pre-war 326.
The first post-war production BMW was the handsome 501 saloon.
Its engine was an updated version of the 326’s 2-litre straight-six, now with a top speed of 86mph.
Criticism of the 501’s underpowered engine led BMW to introduce a more powerful version in early 1954, improving acceleration and upping the top speed to 90mph.
These 1971cc models were short-lived due to concerns over their reliability and BMW replaced them after just a year with a 2077cc, six-cylinder engine with an identical output.
Altogether, BMW built 8951 six-cylinder 501s, which was considerably fewer than the V8-powered model that held greater appeal for luxury buyers.
11. 1968 BMW 2500/2800
Given how closely BMW is associated with straight-six engines, it’s strange to think it didn’t have any such engine in its line-up from 1958-’68, when the new E3 generation of large saloons arrived.
Starting with the 2500 in 1968, which used a 148bhp, 2494cc, six-cylinder motor, known within BMW as the M30, this sharp-suited, four-door model was capable of 118mph.
In 1969, the 2800 arrived with 168bhp from its 2788cc motor, giving 124mph flat out, and aimed at keen drivers with its limited-slip differential and Nivomat dampers.
Both the 2500 and 2800 had engines designed with US regulations in mind, so they did not need power-strangling emissions equipment added.
BMW went on to offer a 177bhp, twin-carb, 3-litre model and the fuel-injected 3.0 Si, while its 3.3-litre models served as the ultimate executive expresses.
12. 1968 BMW E9
The 2000 CS had served BMW well as a graceful coupé, but its four-cylinder engine was not cutting it with wealthy customers.
In 1968, that was resolved with the E9 coupé that used the same silky straight-sixes as the company’s new large saloon.
The 2800 CS was first to arrive in late 1968 with a 2.8-litre motor, which was then replaced by the 3.0 CS in 1971, while the fuel-injected 3.0 CSi had more power than both with 200bhp, while a 150bhp 2.5 CS was the least powerful version.
BMW developed the lightweight, homologation-special CSL version with Alpina, the ultimate edition of which was the 204bhp ‘Batmobile’ with a 3153cc straight-six and electronic fuel injection.
The Batmobile was capable of 137mph and only 169 were ever built with the aerodynamic wings that gave the car its nickname.
13. 1973 BMW 5 Series
BMW launched its new mid-size 5 Series to great acclaim in 1972, but it took until 1973 for the six-cylinder versions to go on sale, led by the 525.
With a 2494cc engine the 525 was good for 120mph. There was also a US- and Japan-only 530i with a 176bhp 2985cc unit and catalytic converter.
The 528 became the top-of-the-line 5 Series in 1975 for most markets with its 162bhp, 2788cc straight-six until the fuel-injected 528i arrived in 1977.
However, if you were in BMW’s inner circle, you could get your hands on the 533i from 1974. Built by BMW’s Motorsport division with a 197bhp, 3210cc, six-cylinder engine, it comfortably but quietly predated the M535i that arrived in 1980 with a 215bhp, 3453cc straight-six and a 138mph top speed.
Following BMW 5 Series generations delivered increasingly powerful and velvety six-cylinder engines, including the beguiling E34 M5.
14. 1976 BMW 6 Series
Replacing the effortlessly stylish E9 generation of BMW coupé was going to take something special, and the 6 Series was exactly that.
The E24 6 Series came with crisp looks courtesy of Paul Bracq, while power was only ever from petrol-powered, six-cylinder engines.
Using the same engines as the 5 Series, with which it shared much of its mechanical make-up, the 6 Series launched with 3- and 3.3-litre units.
These were replaced by the 628CSi with its fuel-injected, 2788cc, six-cylinder motor, and the 3453cc 635CSi from 1978.
BMW kept the best until last when it introduced the M635CSi in 1984. This 282bhp coupé had the same straight-six engine as the M1 supercar, and delivered 0-60mph in 6.5 secs and 158mph.
The 6 Series badge resurfaced in 2003 with a choice of petrol and turbodiesel straight-sixes, as well as a petrol V8.
15. 1977 BMW 3 Series
The new 3 Series was an instant success for BMW with its four-cylinder engines that were familiar from the previous 2002 model. However, the German car maker upped its game with the arrival of the six-cylinder 320 in 1977.
This 121bhp, 1990cc, straight-six model offered greater refinement and a marginally higher top speed than its 320i four-cylinder sibling.
However, the car BMW fans really wanted went on sale from early 1978 as the 323i, complete with a 2315cc, 141bhp straight-six developed for the 3 Series.
Subsequent generations of 3 Series embraced six-cylinder power with gusto with diesel and petrol motors, including the South Africa-only 333i, M3 models with as much as 355bhp in the naturally aspirated E46 M3 CSL and 543bhp in the 2025 turbocharged M3 CS.
16. 1977 BMW 7 Series
Taking the place of the 2500/2800 saloons, the new E23 7 Series fell into line with BMW’s numbering policy and adopted the same straight-six engines used in the 6 Series.
At first, there were 2.8-, 3- and 3.2-litre motors and a choice of manual or automatic transmissions, though most buyers opted for the auto.
Revised engines arrived in time, including a turbocharged, 3210cc straight-six for the model badged as the 745i. With 248bhp, it was good for 137mph to counter Mercedes’ V8-powered S-Class.
There was also a South African-spec 745i that used the 282bhp 3.5-litre motor from the M635CSi and just 192 of these cars were built.
Later generations of 7 Series gained V8 and V12 engines, as well as hybrid and even all-electric propulsion, but a straight-six has remained a constant across the decades.
17. 1978 BMW M1
A straight-six engine was not the obvious configuration for a mid-engined sports car, but it’s what BMW used for its M1.
Conceived as a racing car for the Group 4 category, this didn’t come about but BMW pressed ahead and built 456 examples of the M1 altogether.
Some were used in the one-make Procar Series that supported various European Formula One Grands Prix in 1979 and 1980.
The road car had a 274bhp 3453cc M88 straight-six that gave the low-profile M1 a top speed of 163mph and 0-60mph in 6.5 secs.
Considered the easiest supercar of its era to drive, BMW didn’t replace the M1, but it did use the engine in the M635CSi and M5 models.
18. 1988 BMW Z1
Shown as a design study at the 1987 Frankfurt motor show to test the waters for a new BMW two-seat roadster, the Z1 got an emphatic thumbs up and went into limited production.
While buyers were wowed by its drop-down doors, smooth looks and even the innovative, Z-axle rear suspension, the 168bhp, 2494cc straight-six was often overlooked.
It might have been the same engine as used in the 325i, but it was mounted as a front mid-engined unit to give the Z1 superb handling.
The lusty six-cylinder engine didn’t give the Z1 bristling performance – 0-60mph took 9 secs – but it suited the roadster nature of the car and 8000 customers happily took up the chance to buy one new.
19. 1995 BMW Z3
If the BMW Z1 was ahead of its time as far as the roadster revival of the 1990s was concerned, the Z3 was right in the thick of it.
A perky, four-cylinder engine offered the entry-point to the Z3 range, but keen drivers gravitated towards the 2.8-litre straight-six with its punchy 189bhp and 136mph top end.
This was followed by the Z3M with the same 3201cc straight-six as the M3 producing 316bhp, later 321bhp, and hearty performance of 155mph flat out coupled to 0-60mph in 5.3 secs.
BMW also offered the Z3M in Coupé form, and the hardtop could be had in some markets with 2.8- and 3-litre straight-sixes.
The Roadster went on to enjoy a broader line-up of six-cylinder motors encompassing 2-, 2.2-, 2.3-, 2.5- and 3-litre capacities.
20. 1999 BMW X5
The BMW X5 wasn’t the first luxury SUV by any stretch of the imagination, but it was the first that really could be driven with verve and it was helped in this regard by its straight-six engines.
While the wealthiest X5 owners could have the thirsty V8, most opted for either the 3-litre petrol or turbodiesel units lifted from the E39 5 Series.
Free revving, powerful and, in the case of the diesel, decently frugal, they quickly populated the roads – and both the petrol and diesel ‘sixes’ could reach a top speed of 126mph, which was just 2mph behind the V8 model.
Right up to the 2025 fourth-generation cars, the X5 range has featured straight-six engines at its core.
21. 2002 BMW Z4
BMW took a different tack with the Z4 compared to the Z3. Yes, both were roadsters, but the looks of the Z4 set it apart and it was only ever offered with six-cylinder engines – no four-cylinder, entry model here.
The Z4 got off to a great start in life as a more credible rival to the Porsche Boxster with its 189bhp 2.5-litre and 228bhp 3-litre six-cylinder motors.
Even the 2.5 was good for 146mph, while the bigger engine purred this roadster all the way to an electronically capped 155mph top end.
Smaller 2- and 2.2-litre ‘sixes’ arrived in time, along with the uprated 2.5si and 3.0si motors. These engines arrived to coincide with the launch of the Z4 Coupé in early 2006, and BMW also launched the very rapid Z4 M Roadster and Coupé at this point. These M models used the same 338bhp 3246cc engine as the M3.
The Z4 generations that followed added turbocharged four-cylinder units to the options list alongside the choice of six-cylinder engines.
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