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[YesAuto Technology] After the 2015 North American Auto Show, I had a serious talk with you about the “feelings” of the power system of American cars (click to review: Feelings and the future comment on GM/Ford's latest supercharged engine). Follow the trend or stick to your feelings? This is a problem that the Detroit Big Three have been facing for a long time.

At this year’s New York Auto Show, a brand new flagship model that Cadillac had high hopes for was on the world stage. If 20 years ago, this top Cadillac aimed at rivals such as the BMW 7 Series and Audi A8 would definitely be equipped with a displacement. A huge V-shaped 8-cylinder engine, but today, there is no memory of V8 on this CT6. However, in many people's minds, a huge Cadillac still represents the American luxury in memory. Cadillac is looking forward to using these new 4-cylinder and 6-cylinder engines and the power combination of 8AT gearboxes to land this feeling not only on the American continent, but all over the world.

CT6 powertrain layout

CT6 will have three power units for global consumers to choose from, which are 2.0T inline 4-cylinder, 3.6L V6 and 3.0T V6 twin turbocharged engines. From this setting, it is not difficult to see that the CT6's goal is obviously not only for the North American market, China, Asia and even Europe will be in the firepower of this new flagship.

It can be predicted that in the North American market in the future, entry-level models will be equipped with a 3.6L naturally aspirated engine, and the 3.0L twin-turbo engine will be the top power of the whole series; and in China, 2.0T will replace the 3.6L engine and become the entry-level CT6 Power, and 3.0T also well controls the taxes and fees of the top models. If CT6 landed in Europe, I believe it will definitely adopt the power layout of 2.0T+3.0T. In addition, the three levels of power units will be equipped with GM's latest 8AT gearbox.

In general, CT6 does not continue the tradition of Cadillac's large luxury cars using V8 engines. The new 2.0T engine must be set for markets with more restrictions on displacement, such as China and Europe, and the highest-level 3.0T engine Displacement is obviously more targeted-GM did not use the 3.6T engine previously on ATS-V, CTS Vsport and XTS Vsport, but developed a new engine with a displacement of 3.0L-you know, In many countries and regions outside North America, the difference in purchase and use costs between 3.0L and 3.6L models is a set of numbers that are hard to ignore. In addition, the latest 8AT gearbox can be regarded as keeping up with the world's popular footsteps, at least in terms of the number of gears. The displacement is down and the gear is up, so what is the strength? Now we will work together to solve this question.

3.0L V6 twin turbocharged engine

It should be said that this 3.0T engine, code-named LGW, which appeared to the public for the first time along with the CT6, is the biggest highlight in its power unit sequence. GM hopes to build a small displacement (compared to 3.6L V6 and V8 engines) 6-cylinder engine with excellent power performance and excellent ride comfort as the top power unit of CT6. The new engine comes from GM's current latest V6 engine technology platform, including the existing 3.6L and 3.6T engines from the same platform. Through the use of technical structures such as twin turbocharging, direct injection in the cylinder, and targeted enhancement and optimization adjustments, this 3.0T engine can output a maximum power of 405Ps (298kW) and a maximum torque of 543N·m. In addition, the engine uses a lightweight and small inertia turbine, combined with an integrated exhaust manifold and a water-cooled intercooler, to improve the response speed of the turbine. At the same time, the maximum torque burst range can reach 2500-5000rpm, forming a relatively broad Torque platform.

Cadillac CT6

3.0T

(LGW)

Mercedes-Benz S 400 L

3.0T

(M276)

BMW 740Li

3.0T

(N55)

Audi A8 50 TFSI

3.0TFSI

(EA837)

Pressurized form Twin turbo Twin turbo Single turbo double vortex tube Supercharged

Maximum power

405Ps (298kW) 333Ps (245kW) 320Ps (235kW) 333Ps (245kW)
Maximum torque 543N·m 480N·m 450N·m 440N·m

In order to improve economy, the new 3.0T engine uses a brand-new piston coating to reduce running resistance, and uses a two-pole oil pump. In addition, it also adds cylinder cut-off technology, which can run with only 4 cylinders under low load. To save fuel consumption. All these measures, in conjunction with the engine start-stop system, can ensure that the new engine saves about 6% of fuel compared to similar models.

2.0L inline 4-cylinder turbocharged engine

Although the new 3.0T engine has very eye-catching performance data, in the domestic market, the 2.0T version of the CT6 will obviously be the most popular model. In order to meet the needs of China and other markets, Cadillac has also allowed the LTG 2.0T engine that has appeared on the ATS, CTS and XTS to continue to serve the CT6.

Although it is entry-level power, this 2.0T engine still has considerable strength. Friends who are interested in it can refer to our dismantling of it: the past future star dismantled the Cadillac 2.0T engine. There is no doubt that the introduction of the 2.0T engine has undoubtedly lowered the price threshold for CT6 in China, and at the same time, the lower displacement has also reduced the policy cost of car owners.

3.6L V6 naturally aspirated engine

In addition to the above two turbocharged engines, CT6 also has a 3.6L V6 naturally aspirated engine code-named LGX to choose from. This engine is improved from the 3.6L engine on the current ATS (US version), CTS (US version) and XTS. Through the optimization and optimization of intake/exhaust valves, injectors, spark plugs and cylinder combustion chambers, the maximum power of this latest 3.6L engine has reached 340Ps (250kW) and the maximum torque is 385N·m.

In addition to power performance, the optimization focus of this engine is also on the refinement of NVH, including the adoption of a new camshaft drive system and other measures to make the noise control of this new engine better than Cadillac under idling speed and low load conditions. I set the benchmark object-Infiniti VQ37 series engine. However, I personally think that it is unlikely that this engine will appear on the domestic version of CT6. Its power level is not obvious compared with the 2.0T engine. Only in the high-speed range can it show the advantage of large displacement, while 3.6 The L displacement will inevitably bring more consumption tax and vehicle and vessel use tax, and the cost of buying and using a car will increase a lot.

8AT gearbox

As mentioned before, the entire CT6 series is equipped with GM’s latest 8AT gearbox. The gearbox code for the 3.0T engine is 8L90. After targeted design and enhancement, it can withstand more input torque, so it is used with Cadillac’s latest performance cars ATS-V, CTS-V and the legendary sports car Chevrolet Corvette Stingray and Z06; 2.0T and 3.6L engine gearbox code name 8L45, and 8L90 share the technical platform and structural design, but in the design In certain aspects, it is more tacitly compatible with 2.0T and 3.6L engines.

8L45 8L90
Gear ratio setting
1st gear 4.62 4.56
2 gears 3.04 2.97
3 gears 2.07 2.08
4 gears 1.66 1.69
5 gears 1.26 1.27
6 gears 1.00 1.00
7 gears 0.85 0.85
8 gears 0.66 0.65
Reverse gear 3.93 3.82

Since we have not yet been exposed to the CT6 test drive, we cannot evaluate the actual performance of these two 8AT gearboxes, but from foreign media’s evaluation of the performance of the 8L90 on the Corvette Z06, and my own driving that also uses the 8L90 From the experience of the 2015 Escalade, this 8AT gearbox has reached a very good level in terms of shift speed. As for the 8L45, we will see it on the domestically-made ATS-L, which is remodeled this year, as soon as possible.

to sum up:

GM’s “hometown” and rival Chrysler had this sentence in a TV commercial in the domestic market: “Use strength to let your feelings fall.” For Cadillac, which is preparing to reshape the large American luxury car, this sentence seems appropriate. CT6 undoubtedly carries the beautiful feelings and longings of GM and American car enthusiasts, and to make this feeling truly “landing” and being accepted by global high-end buyers in this level of market, it must rely on real hard power . Judging from the current three sets of powertrains, CT6 has already looked at the global market and has made a very good start. Therefore, in my opinion, its future performance in the market is a very worth looking forward to.