# BMW N74

The BMW N74 is a twin-turbo V12 petrol engine which replaced the N73 and has been produced since 2008. It is BMW's first turbocharged V12 engine and is also used in several Rolls-Royce models.

## Design

The N74 features twin turbochargers, which are not present on its naturally aspirated BMW N73 predecessor. The turbochargers are located on the outside of the engine and use a boost pressure of 11.6 psi (0.8 bar). In its base configuration the engine has a compression ratio of 10:1 and a specific fuel consumption of 245 g·kW$^{−1}$·h$^{−1}$.
Like its predecessor, the N74 has direct injection, DOHC and variable valve timing (called double-VANOS by BMW). However, the N74 does not have variable valve lift (called Valvetronic by BMW).
The N74 marked BMW's first use of an 8-speed automatic transmission, in the form of the ZF 8HP90.

## Versions

| Engine | Displacement | Power | Torque | Year |
| N74B60 | 5,972 cc (364.4 cu in) | 400 kW (536 hp) at 5,250 rpm | 750 N⋅m (553 lb⋅ft) at 1,500–5,000 rpm | 2008–2015 |
| N74B66 | 6,592 cc (402.3 cu in) | 420 kW (563 hp) at 5,250 rpm | 780 N⋅m (575 lb⋅ft) at 1,500–5,000 rpm | 2009–2020 |
| N74B66 | 6,592 cc (402.3 cu in) | 465 kW (624 hp) at 5,600 rpm | 800 N⋅m (590 lb⋅ft) at 1,500–5,500 rpm | 2013–2022 |
| N74B66 | 6,592 cc (402.3 cu in) | 442 kW (593 hp) at 5,250 rpm | 840 N⋅m (620 lb⋅ft) at 1,500 rpm | 2016–2020 |
| N74B66TU | 6,592 cc (402.3 cu in) | 449 kW (602 hp) at 5,500 rpm | 800 N⋅m (590 lb⋅ft) at 1,500 rpm | 2016–2019 |
| N74B66TU | 6,592 cc (402.3 cu in) | 447.5 kW (600 hp) at 5,500 rpm | 850 N⋅m (627 lb⋅ft) at 1,550 rpm | 2020–2022 |
| N74B68 | 6,750 cc (411.9 cu in) | 420 kW (563 hp) at 5,250 rpm | 900 N⋅m (664 lb⋅ft) at 1,500 rpm | 2017–present |

### N74B60

This initial version of the N74 has a bore of 89 mm (3.5 in) and a stroke of 80 mm (3.1 in). The redline is 7000 rpm and the compression ratio is 10.0:1.
Applications:
* 2009–2015 F01/F02/F03 760i/760Li

### N74B66

The N74B66 is an enlarged version of the N74B60, due to a stroke of 88 mm (3.5 in). The redline is 7000 rpm and the compression ratio is 10.0:1. It produces up to 465 kW (624 hp) and is used in the Rolls-Royce Ghost.
| Year | Application | Power output | Torque |
| 2010–2020 | Rolls-Royce Ghost | 420 kW (563 hp) | 780 N⋅m (575 lb⋅ft) |
| 2014–2020 | Rolls-Royce Ghost V-Specification | 442 kW (593 hp) | 780 N⋅m (575 lb⋅ft) |
| 2019 | Eadon Green Panthean Coupe | 442 kW (593 hp) | 840 N⋅m (619.5 lb⋅ft) |
| 2014–2023 | Rolls-Royce Wraith | 465 kW (624 hp) | 800 N⋅m (590 lb⋅ft) |
| 2015–2023 | Rolls-Royce Dawn | 420 kW (563 hp) | 820 N⋅m (605 lb⋅ft) |

### N74B66TU

2016 saw the introduction of the 6.6 liter N74 V12 variant to the BMW 7-series along with some Technical Updates (TU) for reliability. The facelifted 2020 models saw power reduced in the EU market to 430kW (577 bhp) due to emission regulations. This was partially compensated with an increase in torque to 850Nm (627 lb-ft). US models enjoyed the bump in torque with horsepower remaining close to the previous level at 600 bhp. Although the flagship 7-series was marked m760i in the USA and m760Li is some markets, all N74B66TU V12 powered 7-series were long wheelbase (G12); there was no short wheelbase (G11) variant offered world wide.
Applications:
* 2016–2022 G12 M760Li xDrive

### N74B68

The 6.75 litre version was introduced in the 2018 Rolls-Royce Phantom. It is also used in the Rolls-Royce Cullinan and Rolls-Royce Ghost, both of which are built on the same platform as the new Phantom.
Applications:
* 2017–present Rolls-Royce Phantom VIII
* 2018–present Rolls-Royce Cullinan
* 2021–present Rolls-Royce Ghost