Many conversations around driver engagement, including the letters “Si”, would naturally revolve around Honda. After all, those letters have been closely associated with the type of affordable and infinitely drivable car that Honda is famous for. But there’s another Si that comes from BMW and can certainly be placed in the category of a “drivers'” car. It was never officially sold in the US, and it’s a racing homologation special, but it remains relatively attainable. And two decades on from its first appearance, this E90-generation BMW 320si is one of the more unusual bargains in BMW’s back catalog.
BMW Built The 320si Because It Wanted To Go Racing
2005 BMW 320si rear quarterBMW
BMW only built 2,600 examples of its E90-generation 320si. This was a substantially re-engineered version of its 3 Series sedan, meant to serve as the basis for a World Touring Car Championship (WTCC) campaign beginning in 2006. BMW knew that its previous E46-based 320Si racer had been successful, but now that it was working with the E90-generation 3 Series, it needed a freshly minted homologation road car.
With racing goals in mind, BMW produced a limited version of the 320i, with production running from March through September 2006. This was a remarkably concentrated program, resulting in just 2,600 examples, with BMW allocating 500 of them to Britain. The car didn’t come with an M badge, but it was definitely different from a regular 320i. BMW increased the bore of its inline four from 84 to 85 mm and shortened its stroke from 90 to 88 mm. This brought displacement to 1,997 cc while compression increased from 10.5:1 to 11.0:1. The car also had larger intake and exhaust valves to help the engine breathe at higher rpm.
BMW’s engineers also removed the regular engine’s ValveTronic variable valve lift system and introduced a conventional throttle body. They also set the tachometer’s red zone to begin at 7,300 rpm. And considering that this looked like a fairly ordinary compact luxury sedan on the outside, there was a lot of serious engineering beneath.
170 HP Doesn’t Tell You Why This 3 Series Is Interesting
2005 BMW 320si 170hp-engineBMW
Many people imagine that a car built with performance in mind should have extreme power output, but that wasn’t the case here, and that wasn’t necessarily the point either. BMW quoted approximately 170 hp for its new 320si, with around 147 lb-ft of torque arriving at 4,250 rpm. The car would take about 8.1 seconds to reach 62 mph and offer a top speed of 140 mph, but acceleration wasn’t the only metric that mattered. Response, revs, and chassis behavior were more important to this type of performance project than the ability to deliver a huge wave of turbocharged torque.
The maximum power for the 320si arrived at 7,000 rpm, which encouraged the driver to work the engine through its six-speed manual gearbox. A short 4.10:1 final drive ratio also helped make better use of that high-revving power delivery. A standard M Sport package then delivered a sportier suspension setup, and the car came with distinctive 18-inch Style 216 wheels as well.
BMW also paid good attention to the engine. The cylinder head was cast at its Landshut plant, where BMW Motorsport produced key components for its competition engines, and the engine was hand-assembled at BMW’s Hams Hall plant near Coventry. There was also a carbon fiber cylinder head cover to provide a subtle nod to the car’s motorsport purpose.But the real proof of BMW’s engineering ambition wasn’t in the road car at all – it was in what the racing team built on top of it.
The Racing Version Proved Why BMW Went To The Trouble
2005 BMW 320si alongside WTCC racing versionBMW
All that careful engineering in the road car – the high-compression head, the hand assembly, the red line pushed to 7,300 rpm – was just the starting point. Once BMW had finished developing its homologation donor, it went on to create a genuine touring car weapon. And in the 320si WTCC version, a P45 racing engine produced approximately 275 hp at 8,300 rpm. This unit went substantially further than the road engine and featured extensively revised internals and a revised cylinder head.
BMW’s investment paid off immediately. Andy Priaulx entered the 2006 season as the defending WTCC champion, having won the 2005 title with BMW. And driving the new 320si WTCC, he was able to successfully defend his championship in 2006. He also won five races and beat fellow BMW driver Jörg Müller to the title by a single point. At the same time, BMW captured the manufacturers’ championship, scoring 254 points — 19 points more than rival SEAT. Priaulx went on to win the drivers’ championship again in 2007, with BMW retaining its manufacturers’ crown.
All of this success certainly justified BMW’s efforts in developing the road-going 320si. And while the car was never supposed to be a miniature M3 or even the quickest non-M3 in the series, it did give BMW the production foundation upon which it would develop its successful next-generation touring car.
You’d think, of course, that a car with two world championships attached to its bloodline would normally cost a fortune to own. The reality is surprisingly different.
2005 BMW 320si from the sideBMW
A vehicle that can point to its sporting history as well as its relative rarity would normally fetch quite a lot of money on the open market, but that’s not the case with this BMW 320si. Prices will vary depending on mileage, condition, and history, but as an example, a privately listed 2006 example with 116,050 miles on the odometer is advertised for just £2,550, or about $3,330. It does have an engine fault code, needs timing chain work, and comes with a leaking rear shock absorber and other issues, but it still represents a real-world example of the type.
Meanwhile, at the other end of the spectrum, a 67,000-mile privately advertised example is currently listed at £12,995 ($17,300), illustrating how far condition and presentation can stretch the market.
Buyers will need to approach any period 320si with a certain degree of caution. One significant issue revolves around aluminum cylinder liners as a potential failure point. Cracked liners could lead to a loss of compression and more serious failures could damage the internals of the engine.
One independent specialist recommends machining the block to replace the aluminum cylinder liners with steel sleeves. Such work could amount to as much as £4,000 (or $5,500), depending on the engine and the extent of the work needed. And that could certainly be consequential in a vehicle that may itself have cost only a few thousand pounds to buy.
US Buyers Can Import A 320si Starting In 2031 – Here’s What That Means
2005 BMW 320si engine bayBMW
The 320si never reached American BMW showrooms, but that doesn’t mean it will always be off-limits to US drivers. After all, the NHTSA allows a vehicle that’s at least 25 years old to be permanently imported to the US, without needing to comply with the Federal Motor Vehicle Safety Standards applicable when it was new. As 320si production took place between March and September 2006, those cars could become eligible for importation to the US during the corresponding months of 2031.
Certainly, an import would need to comply with EPA emissions requirements, which are evaluated separately. And a buyer would also need to consider shipping costs, duties, registration rules, and the complications of buying a specialist car from overseas. But a BMW 320si from this period should nevertheless be quite interesting.
It’s part of a disappearing category of performance cars where modest numbers often disguise some unusually serious engineering. And it has a naturally aspirated engine that rewards revs, a six-speed manual gearbox, rear-wheel drive, and a chassis that BMW developed when mechanical involvement was central to the company’s sporting identity.
It’s also important to remember that the racing car based on this homologation special went on to become a world champion. So, when you consider that this road-going relative now costs less than many ordinary used commuter cars, it may be time to circle that 2031 calendar month.
Base Trim Engine
2.0L Turbo Inline-4 Gas
Base Trim Transmission
8-Speed Automatic
Base Trim Drivetrain
Rear-Wheel Drive
Base Trim Horsepower
180 hp
Base Trim Torque
200 lb-ft @ 1250 – 4500 rpm
Fuel Economy
24/36 MPG
Infotainment & Features
8 /10
Sources: BMW, Element Performance, NHTSA.
