Reviewed: Cadillac CTS-V Coupe (2011 Model)

I like this car for more reasons than I can count on my fingers. The sloopy coupe's story starts with its engine, a supercharged V8 with 556 HP. That number means the CTS-V has four times the power of a compact car driving only a margin more weight. It translates into a very fast car, capable of reaching 60 mph from a standstill in around four seconds. The story doesn't end there though. The CTS-V Coupe has been equipped with a bevy of high tech features that make a car which is among the most impressive grand touring cars currently produced.

The deeply sculpted hood and flashy grill are intimidating

The CTS-V Coupe blends an interesting dichotomy of new and old technology together. On one hand the shock absorbers, which are the most important dynamic part of the suspension, use a cutting edge technology that is also found on top tier Ferraris. On the other, the motor uses a simple valvetrain technology which has only one camshaft where most modern V8s have four. The engineers have done a good job of placing technology where it is needed to deliver maximum product.

I'm lucky enough to own the car pictured in this article, and before purchasing it I was lucky enough to be invited to Monticello Raceway in New York to drive a CTS-V at its limit. Having come from a smaller less powerful Volkswagen GTI, adjusting to the CTS-V was easier than I expected. Especially with an automatic transmission the car is placid when driving casually. The high tech shock absorbers do a good job of smoothing pavement in their touring mode. While driving around town or flying down the highway the car is docile and compliant. However, the personality of the car is split. There is an exciting side to the car, raw and dangerous feeling.

The CTS-V's optional Recaro seats

The interior of the CTS-V is as strong as its motor with classy design, top quality upholstery, and pleasing accent lighting. The seats, produced by Recaro, feature heating, cooling, inflatable bolsters, extendable thigh support, and a bevy of electronic adjustments. I find them very comfortable and supportive.

The raked lines regularly attract passing attention

Digging Deeper

As part of the format I will use to write reviews, this section will investigate important product features as they relate to actual performance. Expect to learn what impact engineering decisions make in every day use.

Engine Specifications

• Horsepower: 556 hp
• Torque: 551 lb-ft
• Type: V8
• Displacement: 6.2L
• Block material: Aluminum
• Valvetrain: Single cam, push rod (OHV)
• Valves per cylinder: 1 intake, 1 exhaust
• Fuel system: Port injection
• Forced induction: Supercharged
• Supercharger: 1.9L w/ integrated water-to-air intercooler
• Maximum charge: 9 PSI
• Recommended oil: Dexos 1 certified full synthetic
• Recommended gasoline: 91 octane or higher

The GM LSA motor as found in the CTS-V

Digging into the Engine

As mentioned above, the CTS-V's engine (GM engine code LSA) uses an old valvetrain scheme called OverHead Valve (OHV). By far the majority of V8s produced, especially those in performance cars, use another scheme called Dual OverHead Cam (DOHC). Let's find out why engineers made this decision.

The valvetrain is responsible for timing the inflow of air and fuel into the cylinders and the outflow of exhaust gasses. Most modern motors have a separate camshaft for each set of intake and exhaust valves. Each camshaft works by spinning a lobe for each valve and the valve is pressed against its lobe by a strong spring. The lobe is shorter on one side and longer on the other, and as the lobe is spun by the camshaft, the valve opens and closes.

An OHV mechanism for one cylinder 

The CTS-V's motor has only a single camshaft for all the valves nestled between the V of cylinders. This compares to four camshafts on most V8s. The single camshaft is connected to the valves via a pushrod for each valve. In the picture, you can see these pushrods leading from the center camshaft, up over the cylinders to rocker arms which are attached down to the valves.

Despite OHV being simpler mechanically than multiple camshafts, it is actually a newer design dating to 1949 compared to DOHC dating to 1924. The simplicity of the design mostly comes from having only one timing sprocket to turn versus four and lubricating only one cam versus four. DOHC V8s need a comparatively complex set of chains or belts to drive all four camshafts in precise unison and a large housing for each pair of cams to keep them lubricated. In addition to being simpler, OHV is lighter and more compact since the camshaft occupies the area between the V versus space above the motor. This packaging change leads to a surprisingly compact and light motor. It is not uncommon for a large displacement OHV V8 to be physically smaller  and lighter than a low displacement DOHC V6.

The OHV design does have disadvantages however. The amount of space for pushrods and cam lobes limits the number of valves per cylinder to two versus DOHC motors having three to five. More valves per cylinder increases efficiency. Also it is difficult to implement Variable Valve Timing (VVT) on OHV motors. VVT is an increasingly more common technology that changes when valves open and close on the fly to improve efficiency and power.

A 4.6L DOHC V8 engine next to a 4.9L OHV V8 engine

The CTS-V's large 6 piston floating calipers

Drivetrain Specifications

• Configuration: Front engine, rear wheel drive
• Transmission: TR6060 6 speed manual
• Differential: Mechanical locking limited slip differential
• Brake calipers (front, rear): 6 piston floating/4 piston floating
• Brake rotors (front, rear): 15" ventilated/14.7" ventilated
• Wheels (front, rear): Forged aluminum 19" by 9", Forged aluminum 19" by 10"
• Tires (front, rear): Michelin Pilot Sport 2 255/40,  285/40

Digging into the Drivetrain

Perhaps the most important part of a performance car, even more important than the motor, are the tires. This idea might be hard to swallow, but my thinking comes from years of firsthand experience on the track. A fast car with poor tires will be slow and a slow car with great tires will be fast. The rationale for this phenomenon can be summed up by imaging the car as a line of parts in order from action to reaction: engine → transmission → propeller shaft → differential → half shaft → suspension → brakes → wheels → tires. Tires are the closest part to the reaction, and thus have the largest impact on all types of performance.

Two Michelin Pilot Sport 2 tires

The CTS-V's tires are a summer performance model by Michelin that offer high levels of road holding in summer temperatures. Because tires are critical in overall performance, they can also be the largest performance compromise on a car. The CTS-V's tires demonstrate this compromise by becoming dangerously low in traction at freezing temperatures.

Other than being a summer-only tire, the CTS-V's tires are a good balance between high levels of traction and usability. They resist hydroplaning well, have good wet traction, and a moderate tread life.

The science of tires is constantly advancing. Advances in tread patterns, material formulas, and material composite design mean every new model may produce a big improvement in performance. Staying on top of the newest tires is the best thing someone can do to improve their car's performance and safety.

The CTS-V's angular rear lines

Chassis Specifications

Wheelbase: 113.4"

Track width (front, rear): 61.8", 62.8"

Front suspension: Independent Short/Long Arm (SLA)

Rear suspension: Independent multi-link

Steering: hydraulically assisted

Shock absorbers: 2-mode active magnetorheological

Antilock Braking System: 4 channel

Traction Control System: Wheel spin prevention via 2 channel braking, engine, and suspension control

Stability Control System: Yaw and rollover correction via 4 channel braking, engine, and suspension control

Digging into the Chassis

Magnetorheological Shock Absorber

The CTS-V's chassis is a mix of sophisticated technology, with the most striking being the advanced active shock absorbers. Shock absorbers are the most important part of controlling the process of a car transferring load from chassis to the wheels. When a car begins turning, the chassis transfers load (created by gravity and inertia) to the outside wheels. Softer shock absorbers transfer load slowly from one wheel to another while harsh shock absorbers transfer load quickly.

The two-mode active dampers in the CTS-V change their harshness setting every millisecond based on input from several sensors across the car and a sophisticated relatively new technology. This capability allows the CTS-V's suspension to precisely react to split-second conditions for the best possible setting, which increases performance.

The magnetorheologic technology in the shock absorbers uses a fluid that reacts to a magnetic field created by an electromagnet. As the electromagnet becomes charged and creates a stronger field, the special hydraulic fluid becomes less fluid, making the shock absorber become stiffer. The CTS-V has two modes for the suspension, Touring and Sport, which set the suspension to two different baselines of stiffness. The suspension reacts actively in both modes.

Would you buy it?

I did! This car has great charisma and is easy to like for its new asking price of $64,515. The upsides are great performance, looks, and price compared to competitors. The downsides are some build quality issues, thirsty motor, and a short range. It is easily the most impressive performance car in Cadillac's 110 year history.