Cadillac CT6


Debut: 2016
Maker: General Motors
Predecessor: Cadillac STS



 Published on 10 Mar 2016 All rights reserved. 


Cadillac has been falling for decades – actually since its peak in the late 1950s. Those remember that it was once the world standard for luxury cars must be very old or already dead. In recent years, General Motors is keen to revive Cadillac as a world-class luxury car brand, something truly comparable to Mercedes and BMW without resorting to heavy discount or fleet sales. The new ATS and CTS show some promising signs. Although their sales numbers have been disappointing (perception takes time to change), I believe sooner or later it will get the success it deserved providing it keeps pushing relentlessly. In the latest round of “the empire strikes back”, its battlefield is stretched to the range-topping F-segment. The new luxury limousine is called CT6.

We have been missing large Cadillacs since the demise of STS and DTS four years ago. Fortunately, Cadillac has not forgotten its roots. The CT6 is part of a huge, $12 billion investment program under which 8 all-new vehicles will be introduced. They will adopt a new nomenclature, too. Sedans will be called CT-plus-number, while SUVs will be XT-plus-number, where the number denotes class positioning. This means the ATS and CTS could be renamed to CT4 and CT5 respectively in the future.



The CT6 is large, unquestionably. It measures 5184 mm from nose to tail and 3109 mm in wheelbase, longer than a standard-wheelbase Mercedes S-class or BMW 7-Series. However, it is incredibly lightweight. The range starts at 1659 kg with a four-cylinder engine and RWD or 1781 kg with V6 and AWD, considerably lighter than other cars in the class. No wonder Cadillac describes it as the size of 7-Series and the weight of 5-Series. What makes the lightweight possible is an aluminum-intensive multi-material construction. It consists of mostly aluminum and high-strength steel, including 13 high-pressure cast aluminum parts used in the lower structure. All body panels are aluminum. The structure is fabricated by adhesives, rivets, laser welding and a newly developed aluminum spot welding. Overall, 64 percent of the structure (including skins) is made of aluminum. It saves 99 kg compared with an equivalent structure made of high-strength steel.

The CT6 is the first application of GM's new rear-drive Omega platform. Naturally, it is classier and more advanced than the Alpha platform underpinning ATS and CTS. Its front suspension is a double-wishbone-based multi-link setup, while the rear is a 5-link arrangement. Both are constructed largely in aluminum to save unsprung weight, while Magnetic Ride Control provides infinitely variable damping. To make the large car agile to steer, it is served with active rear-wheel steering (like BMW 7-Series). Cadillac claims it offer class-leading ride and handling, something we should not ignore after witnessing the accomplishment of ATS and CTS.



The base 4-cylinder model is rear-wheel drive, but V6 engines mate with a new active on-demand AWD system. It employs a variable clutch and a transfer case to distribute power to the front wheels. In Normal mode, 60 percent power goes to the rear axle. In Sport, this is increased to 70 percent. Winter mode splits 50/50 to enhance traction. As the AWD system is designed to work permanently, its transfer case features 2 gears, one for low speed and one for high-speed cruising, so that fuel economy is improved.

There are 3 engines. The entry-level choice is the familiar 2.0-liter direct-injection 4-cylinder turbo, carried over from ATS and CTS and makes 265 hp here. It is unusual for a large luxury sedan to employ a 4-banger, which is traditionally seen as disgraceful (Mercedes used 4-cylinder engine only on the hybrid S-class). Perhaps Cadillac wants it to capture the lower end of the market segment. After all, the lightweight chassis makes such a small engine acceptable.

More conventional choice is a pair of new generation V6s. LGW is a 3.6-liter naturally aspirated unit with direct injection and cylinder deactivation. It produces 335 hp and 284 lbft of torque – the latter is actually slightly less than the turbo four. LGX is a 3.0-liter twin-turbo direct injection V6, again equipped with cylinder deactivation to save fuel. It produces 404 hp and 400 lbft of torque, saving the need for a V8 engine. However, rumors said a new 4.2-liter twin-turbo V8 is being developed for the forthcoming Vsport model. All 3 engines work with GM's new 8-speed automatic transmission.



In terms of mechanicals, the CT6 seems to be competitive against the best of the world. However, as a flagship luxury car, it underwhelms in many subjective areas. One of them is styling. While the CTS-inspired front-end design looks graceful enough, its side view is dull, and the blocky trunk has no aesthetic to speak of. Moreover, it lacks the elegant fine details that a top-notch luxury car needs. As a result, the visual quality fails to match the likes of Mercedes or BMW.

Inside, the cabin design is equally disappointing. It looks busy and lacks coherence. The woods, carbon-fiber trim and leather mix and match arbitrarily without showing a clear design philosophy. Quality feel is hampered by using too many plastic bits here and there. The TFT color instrument is more attractive to look than conventional dials, of course, but its graphics are plain and the numbers are overcrowded. Most controls lack the slick touch and impeccable feel of those on German limousines.

The CUE infotainment system is once again its single biggest flaw. Although its touchscreen has been enlarged to 10.2-inch, the menus have been simplified and a touchpad has been added on the transmission tunnel as an alternative input, it is still frustrating to operate while the car is moving. Why not simply use a tactile rotary control knob like its German rivals?



Still, the cabin offers acres of room. The front seats are comfy. Rear passengers are served with a 4-zone climate control, entertainment screens as well as reclining, heated, cooled and massaging seats. This large Cadillac will be sold globally – yes, for the first time perhaps – but a lot of them are expected to serve Chinese customers who would spend time only at the back seat.

However, those willing to take the driver seat will find pretty good fun, especially on the base 2.0 Turbo model. Its nose is lighter, and the whole car is light yet stiff. It steers faithfully and delivers good road feel into your hands. Body roll is well checked by the magnetic ride control suspension while ride quality is generally smooth. The four-pot engine is surprisingly refined under the bonnet of CT6, transmitting little sense of vibration and noise into the cabin. It also pairs well with the 8-speed automatic to achieve a smooth and linear power delivery. At speed, the Cadillac remains whispering quiet, just as you would expect for a world-class limousine.



The V6 models are less remarkable. With a heavier nose and compulsory 4WD that complicates the steering feel, they are not as nimble or as communicative as the 2.0 Turbo. The naturally aspirated 3.6 V6 needs to work harder to deliver extra performance. The twin-turbo V6 is more effortless to do so, but neither would you call it a sports saloon, because it takes over 5 seconds to go from 0-60 mph. The V6s are smoother, of course, but the transmission does not shift as precisely when mate with them. 4-wheel steering regains some agility at slower corners, but in faster bends it fails to tame the understeer.

As the first effort to re-enter the top luxury segment, Cadillac CT6 has quite a lot of areas to improve. Its styling shall be more elegant. Its build quality and finish should be improved. Its infotainment system should be overhauled. More power won't be wrong. Having said that, the base 2.0T model with its crisped handling and bargain price should find a unique space in the market segment.
Verdict:
Specifications





Year
Layout
Chassis
Body
Length / width / height
Wheelbase
Engine
Capacity
Valve gears
Induction
Other engine features
Max power
Max torque
Transmission
Suspension layout

Suspension features
Tires
Kerb weight
Top speed
0-60 mph (sec)
0-100 mph (sec)
CT6 2.0 Turbo
2016
Front-engined, RWD
Aluminum + steel monocoque
Aluminum
5184 / 1879 / 1472 mm
3109 mm
Inline-4
1998 cc
DOHC 16 valves, DVVT
Turbo
DI
265 hp
295 lbft
8-speed automatic
F: multi-link
R: multi-link
-
245/45R19
1659 kg
149 mph (c)
6.1*
17.6*
CT6 3.6
2016
Front-engined, 4WD, 4WS
Aluminum + steel monocoque
Aluminum
5184 / 1879 / 1472 mm
3109 mm
V6, 60-degree
3649 cc
DOHC 24 valves, DVVT
-
DI, cylinder deactivation
335 hp
284 lbft
8-speed automatic
F: multi-link
R: multi-link
Adaptive damping
245/45R19
1781 kg
155 mph (limited)
5.9*
14.3*
CT6 3.0 Turbo
2016
Front-engined, 4WD, 4WS
Aluminum + steel monocoque
Aluminum
5184 / 1879 / 1472 mm
3109 mm
V6, 60-degree
2990 cc
DOHC 24 valves, DVVT
Twin-turbo
DI, cylinder deactivation
404 hp
400 lbft
8-speed automatic
F: multi-link
R: multi-link
Adaptive damping
245/40R20
1853 kg
155 mph (limited)
5.0* / 5.0**
12.2*




Performance tested by: *C&D, **MT





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