Cadillac Announces New 3.0L Twin-Turbo LGW 400HP V6 ‘LGW’ Engine For Upcoming 2016 CT6

Cadillac today announced a new family of six-cylinder engines, which will be featured in the upcoming 2016 Cadillac CT6 full-size sport-luxury sedan. The highlight of the new engine lineup is this 3.0-liter twin-turbocharged V6 engine which “leverages the latest technology to balance efficiency, performance and refinement,” in the range-topping luxury sedan, Cadillac says.

Carrying production code LGW, the 3.0-liter twin turbo engine will be mated to the 8L90E eight-speed automatic in the CT6. The combination makes 400 horsepower and 400 pound-feet of torque, qualifying it as one of the most power-dense V6 engines in the world. It’s also one of the most powerful six-cylinder engines in its segment, topping BMW’s 315-horsepower 3.0L twin-turbo inline-six and Audi’s 3.0L supercharged V6. According to Cadillac, the 3.0L LGW V6 will be exclusive to its vehicles and not shared with others from among GM.

Last year, General Motors product chief Mark Reuss said that the CT6 would be “the most advanced vehicle technologically in the world,” and with the debut of the full-sizer’s new 3.0-liter twin-turbo LGW engine, we’re beginning to see what he meant. The power unit is the only one in the world to combine turbocharging, stop/start technology and cylinder deactivation to preserve fuel, a combination which by itself improved fuel economy by six percent. The engine also boasts several new features designed to improve refinement and reduce noise levels including:

  • A stronger, stiffer aluminum block with increased structure in the bulkheads for superior rigidity
  • Tough, refined rotating assembly with a stiff forged-steel crankshaft, friction-reducing polymer-coated pistons and strong high-copper-content, sinter-forged connecting rods
  • New four-cam phasing system with intermediate park technology that enhances efficiency by enabling late inlet valve closing in certain conditions
  • All-new, patented “targeted” cooling system that provides strategic cooling of the engine’s hottest areas while simultaneously fostering faster warm-up, which enhances efficiency
  • New cylinder heads that enhance combustion performance and include direct injection and feature integrated exhaust manifolds
  • Revised, simplified timing drive system with cushioned chain sprockets contributing to quieter engine operation
  • All-new oiling system which moves the pump inside the block for quieter operation. The two-stage oil pump also enhances efficiency

These features will also be present in the entire range of new Cadillac V6 engines, however the 3.0-liter engine has several specific components that help with the additional 18 psi of cylinder pressure provided by the turbochargers. To start, the 86mm bore stroke is 10 percent smaller than that in new naturally-aspirated 3.6-liter LGX, which allows for smaller and lighter pistons. There’s also larger 36mm intake valves and 29mm exhaust valves, and a lower 9.8:1 compression ratio.

The turbochargers use lightweight, low-inertia titanium-aluminide turbine wheels, similar to the ones used in the ATS-V’s twin-turbo LF4 V6. Combined with a patented low-volume charge-air cooler, the turbos help sustain peak torque from 2,500 rpm all the way to 5,000 rpm. Cadillac says the engine produces “nearly zero turbo lag” thanks to the small size of the turbos and their featherweight titanium turbines. Additionally, a single, centrally-mounted throttle body has been used instead of two separate units, which also contributes to improved engine response and torque delivery.

The new 3.0-liter V6 engine will be built alongside Cadillac’s new 3.6-liter engine at GM’s Romulus Powertrain assembly facility in Michigan. GM invested $540-million into the plant in 2013 in order to accommodate production of the new engine family.

Sam loves to write and has a passion for auto racing, karting and performance driving of all types.

Sam McEachern

Sam loves to write and has a passion for auto racing, karting and performance driving of all types.

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    • umm... this engine has nothing to do with the 3.0 from the equinox, this 3.0L TT is an all new engine, they're completely different

      • You are correct only the size is the same.

        Turbo 3.0 liter has been found by most engineers to be the best size for Mileage performance and refinement by most MFG. This is why so many companies are all doing the same size. Same with 2.0 4 turbo and 4.0 turbo v8 engines.

        We will also see 1 liter Turbo 3 cylinder more often too.

  • Yes I agree Grawdaddy, but GM needs to still transfer a little of this quality stuff to the Chevys, GMCs and Buicks in order to make those products even more competitive in their segments.

    No don't put that 3.0TT in a non Cadillac product, but a derivative of that LGX NA 3.6 V-6 must see duty in the 2016 Camaro, certain Buicks and GMCs as well. After all, this new 3.6 should be use to enhance other GM products, thus improving GMs overall image.

  • I think many would agree that from the 30's to 1960's GM was in it's prime. Cadillac pretty much lead the way with automated systems and leading technology in the cars. Advancements like OHV and other things that trickled down to the other lines and even Chevy.

    GM by 1957 really tried not to hide that many of the advancements that started high up were being put into all their products even Chevy> Even the 57 Chevy was alluded to be a average mans Cadillac.

    You can trickle down technology and image but over time GM tried to just revamp platforms conceived as a general GM platform and tried to dumb them up to be a Cadillac. They sprinkled the Cadillac's with some extra not ready for market technology and killed the brand.

    The Cimarron [Chevy}, Catera {Opel} were their worst forms of this attempt as was the 864 engines and other mistakes.

    GM has learned that a half hearted attempt worked back in the 90's to just a few years ago but only to a point. Finally they got the company to learn they had to fully commit to make the change happen and it will still take even more time now they fully have gone all in.

    We will see this engine deal sort itself out over time but we still will see some sharing for the near term as they have a lot of work to create their own line of product and to find ways to build world class engines in low volumes be it all in house of if they join forces with someone like Ilmore, Cosworth etc.

    For right now the CT6 and the new engines will be the next step but they are still not the exclusive Cadillac product we will see. This was the vision of Cadillac before GM going all in. If you like this be aware it will only get better.

  • As I said, that's just the first sign that the CT6 will be the first true Cadillac that North America has always wanted to see.

    The first car to return the pride of true American luxury, but Lincoln also going well

    Regards from Spain

  • I'm curious. All the descriptions on the new 3.0 liter twin turbo state the differences from the outgoing 3.6, including the lower compression ratio. But nowhere does it state whether it requires premium or regular gas. Does anyone know?

  • While Im excited about this engine and its design seems pretty perfect I drive a saturn sky redline with 2.0 liter 4cyl that is incredibly power dense and love it. my engine is 7 yrs old so this isnt to me as innovative as I know gm engineers can be has gm considered making a TT4.0 liter v8 again with a 3 mode cylinder deactivation that would give u a high output v8 3.0 liter v6, 2.0 liter 4cyl all with forced induction in a single package i cant think of a more perfect engine IMO and if it was as power dense as mine the potential for well over 520 hp!! if you want to win wards best engine this is what you build GM. you already have the technology just need this package.

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