Ask any car enthusiast or even someone with the least possible idea about cars, and the first car brand that pops out in his mind when it comes to luxury on wheels is Rolls-Royce. The sheer excellence and no compromise in luxury and elegance have helped Rolls-Royce gain that stature of the last word in luxury. While many people are charmed by the mighty road presence and impeccable levels of luxury of Rolls-Royce models, another trait of those cars with high-set benchmarks has to be the mammoth 6.75-liter V12 engine under their hood, the best one in the history of engines from Rolls-Royce.
With the discontinuation of Wraith and Dawn from the Rolls-Royce global lineup, the 6.75-liter V12 engine has become a mutual heart for all the Rolls-Royce models. Known as N74B68 internally, the 6.75-liter V12 Rolls-Royce engine is the ultimate word in calmness and refinement, unlike other V12s which are known for their fire-breathing performance and dramatic exhaust notes.
The First Rolls-Royce Engine to Use Turbochargers
Unlike the naturally-aspirated N73 series V12 engine from the previous-generation Rolls-Royce Phantom, the new N74 series engine used in the current-gen Ghost, Phantom, and Cullinan uses twin turbochargers. It makes this 6.75-liter engine the first-ever turbocharged powerhouse for the Rolls-Royce models. These two turbochargers are placed outside the V12 engine and use a boost pressure of 0.8 bar.
The turbochargers are not the only elements that are firsts for this 6.75-liter N74B68 V12 engine. It is also the first engine for Rolls-Royce to use the ZF-sourced 8-speed automatic transmission. This engine retains the direct injection tech, double overhead camshafts, and variable valve timing from the N73B68 from the previous-gen Phantom. However, it misses out on the variable valve lift from the previous-gen engine, which allows the intake valve to open and close depending on the engine speed and load.
The Current 6.75-Liter V12 Is The Most Powerful Rolls-Royce Engine Ever
Termed N74B68, the current-generation 6.75-liter twin-turbocharged V12 engine is the mainstay for all the Rolls-Royce current lineup – consisting of Ghost and Phantom sedans and Cullinan SUV. This engine pumps out a maximum power output of 563 hp, thus making it the most powerful engine to ever go under the hood of a Rolls-Royce model. However, the power output of this 6.75-liter engine is not the benchmark for the V12 engines made ever, as it is lesser power than the N74B66TU V12 from the G11 BMW 7-Series.
Where the 6.75-liter N74B68 beats every other V12 engine in the history of internal combustion engines is its massive torque output. This engine produces 627 lb-ft of torque in the Ghost and 664 lb-ft in the Cullinan SUV and Phantom VIII flagship sedan.
Developments That Led To The Birth Of The Current 6.75-Liter Rolls-Royce Engine
In terms of cubic capacity, the 6.75-liter twin-turbocharged V12 engine used in the current Rolls-Royce lineup is the largest in the N74 series of V12 powertrains from Rolls-Royce’s parent company, BMW. Termed N74B68, this 6.75-liter V12 engine first came out in 2016 in the Phantom VIII. However, the N74 series engine debuted in 2008 with the 6.0-liter V12 in the BMW 7-Series. This engine further paved the path for the developments leading to the 6.6-liter V12 used in Rolls-Royce models like Ghost, Wraith, and Dawn.
The first-ever iteration of the N74 series engine, the 6.0-liter V12 N74B60, was used in the F01 and F02 BMW 7-Series. In the BMW’s flagship sedan, this engine claimed 536 hp of maximum power and 553 lb-ft of maximum torque. This engine also evolved into a larger-in-size 6.6-liter V12 N74B66 engine exclusive for Rolls-Royce Wraith and Dawn, in which this engine produced power outputs between 563-624 hp and torque outputs between 575-620 lb-ft.
For the G11 7-Series, BMW tweaked the N74B66 engine, which was reserved for Rolls-Royce until now. In the M760Li xDrive M Performance version of the 7-Series, this engine, dubbed as N74B66TU for the 7-Series, claimed 600 hp of power and 590 lb-ft of torque. The torque output further increased to 627 lb-ft in the last-ever iteration of the G11 7-Series.
The 6.75-Liter V12 Rolls-Royce Engine Might Be The Last Of Its Kind
Rolls-Royce is already committed to going all-electric by 2030, and the shift has already begun with the arrival of the all-new two-door Spectre. Considering that less than a decade is remaining to complete the all-electrification process, the 6.75-liter V12 N74B68 might be the last gas-powered engine for the Rolls-Royce models. Considering this theory, the N74B68 6.75-liter V12 will go into the history books as the perfect ode to Rolls-Royce’s glorious collaboration with mighty V12s.
Currently, Rolls-Royce is one of the limited carmakers who still haven’t adapted any form of electrification for its IC engines. However, considering that the 6.75-liter V12 engine still has some years in existence, Rolls-Royce might electrify it by giving it hybrid assistance until it achieves complete electrification for its entire lineup by 2030.