Infiniti’s QX55 Crossover: CUE THE BUZZ – OR NOT

Infiniti’s QX55 Crossover

CUE THE BUZZ – OR NOT

Strengths and Weaknesses

Strengths:

• Bold and distinctive design
• Powerful turbocharged engine
• Standard AWD
• Luxurious and well-crafted interior

Weaknesses:

• Cargo space limited
• Below-average fuel efficiency
• Overly complicated engine
• Infotainment system cumbersome to navigate at times
• Ride quality might be firm for some
• Value proposition lags German competitors

Let us examine the whiz-bang gadgetry of variable compression engines for an object lesson on why electrified—I did not say electric—vehicles will replace internal combustion engines sooner rather than later.

I remember how excited I was seven years ago when I first laid hands on a vehicle powered by turbocharged VCE, which Nissan had spent the better part of 20 years developing. 

A great notion

The promise was great. By dynamically adjusting the compression ratio, the engine could use less fuel when cruising while developing greater power when accelerating.

Compression ratios express how much the air-fuel mixture squeezes together during a cylinder’s up-down cycle. If a cylinder has ten units of air and gas at its lowest point and that is compressed to one at its highest, it has a compression ratio of 10:1.

Compression is critical to ICE efficiency. As diesel engines demonstrate, compress the mixture enough, and it will ignite spontaneously. This is why diesel engines are more efficient than gasoline-powered ones that use spark plugs to produce explosions that come earlier in the cycle but result in smoother, quieter operation.

High compression wrings more energy out of fuel, but depletes the engine’s power. Lower compression ratios, which are more compatible with turbochargers and superchargers, best achieve that. A VCE uses a Rube Goldberg contraption inside the engine to create high compression ratios at cruising and making low compression ratios available during acceleration.

A high compression ratio slightly offsets ICEs’ chief drawback: they are grossly inefficient. Only 20-30% of the fuel is converted into energy that propels a vehicle, called locomotive force. The rest is lost to heat, parasitic doodads on pulleys, or exhaust gas. Electric motors convert more than 85-90% of fuel into locomotive force with 1/10^th of the moving parts.

To stay relevant and competitive, ICE makers must find a way to be as fuel-efficient as possible. Several attempts in that direction are now in the market. 

One is small displacement, high compression turbocharged engines, which are marginally more efficient but are proving less dependable than the larger, naturally aspirated V-6s they replaced. 

Once upon a time, when gas was equivalent to about a nickel a gallon in today’s currency, manufacturers kept the public satisfied with ever-larger, ever-more-potent engines. Along came manufactured shortages and climate decline because we pump enormous amounts of carbon into the atmosphere, and fuel efficiency became a thing.

Dropping V-shaped engines from eight to six cylinders made a significant improvement, as did variable timing of intake and exhaust valves. Since then, the line has become curvilinear, and the rate of improvement is flattening out. A string of hyped technical advancements has resulted in diminishing returns. 

One that arrived with significant promise but produced marginally better results is shrinking the engines while blowing more air through them. Technically, these are small displacement, turbocharged or supercharged engines.

All that air must go somewhere, and it often takes with it the oil lubricating the cylinders. When vaporized oil reaches the valve train or electrical or exhaust systems, dreadful things begin to happen. 

In 2023 alone, more than 12.4 million Ford and Honda small displacement vehicles were affected by National Highway Safety Transportation Agencies because of the risk of fires or catastrophic failure. Last year, NHTSA forced Hyundai and Kia to issue “park outside” orders for 3.3 million vehicles that could catch fire even when turned off.

The other big idea is the VCE, which early “off the record” reports said could improve fuel economy by a third.

Reality meets road

“Wow,” I told the Nissan engineer who sat in the passenger’s seat on a 2018 Nissan QX-50 while I zipped through a few hot laps around a closed-circuit track. For what it was, the car was average in ride and handling, but with that revolutionary engine? Oh, My!

“If this thing gets even close to 35 mpg,” I told the nice young man with the pocket protector, “you have a better mousetrap on your hands.” “Uh-huh,” he muttered, closely examining his shoestrings—was one untied?—instead of looking me in the eye.

“Ruh-Roh,” I thought. 

When the EPA finished testing, it rated the QX-50 at a combined 23 mpg, which is low for its class and not even in the ballpark with a competitor like the Lexus RX 350 hybrid, which is more powerful, more dependable, and returns 36 mpg.

And that is the point. Marrying hybrid technology to an ICE is like weaving a bionic force into its nervous system, When the engine needs oomph, the electric motor does the job. When it needs to slow down, the same motor captures the excess kinetic energy to charge the battery and save the brakes. 

A plug-in hybrid can double or triple one’s real fuel efficiency. It offers 30-40 miles of all-electric driving before seamlessly flipping over to high-efficiency gas/electric operation. Those who can do their business in that amount of miles will rarely purchase gasoline. Batteries that deliver up to 70 miles on an overnight charge on a 110-watt outlet are just over the horizon.

Not only does Nissan’s variable compression engine significantly improve fuel economy or performance, but it may also be dangerous. NHTSA is investigating turbocharged VCE Rogues and Altimas for failures, including knocking sounds and total engine failures.

In a way, the engine in the QX-55 is a metaphor for the whole car: undelivered promises. The system’s complexity and weight do not justify the marginal gains in efficiency. Though it seeks to battle upscale and expensive vehicles, driving is not fun. The engine has an Asiatic buzz but no head-snapping power when pressed hard.

2024 Infiniti QX55: A Statement Piece 

The 2024 Infiniti QX55 starts well enough. It is a head-turning coupe-styled crossover that merges progressive design with a focus on luxurious highway cruising. This appeals to a specific niche: the single driver who prioritizes a statement-making vehicle for the open road and embraces the latest technology.

With a sleek, sloping roofline and muscular stance, the signature Infiniti grille, and two-tone paint schemes available, the QX-55 exudes modern sophistication. 

Power Meets Handling

Under the hood, the QX55 has a 2.0-liter turbocharged four-cylinder variable-compression engine, producing 272 horsepower and 280 lb-ft of torque. While not ferocious in its class, it delivers a satisfying power surge and impressive top end. Road & Track puts the top speed at 137 mph. We will take their word. 

Standard all-wheel drive ensures stability and control in various weather conditions. Unlike some rivals, the QX55 prioritizes on-road dynamics over serious off-road capability. With a well-tuned suspension, the car feels well-planted at speed on a winding mountain road.

A continuously variable automatic transmission—another contentious issue among wrench turners—offers smooth power delivery. 

Luxurious sanctuary

The QX55’s interior is a haven of contemporary luxury. High-quality materials like leather and soft-touch plastics create a sophisticated ambiance, while a minimalist design philosophy emphasizes clean lines and intuitive ergonomics. 

A dual-screen infotainment system is available, offering a plethora of features, catering to the tech-savvy driver. However, we found the arrangement distracting, often forcing us to mine multiple levels for simple functions—a dangerous pastime on busy thoroughfares.

The car frequently lost communication with our Apple phone, and while exploring the Ouachita Mountains, we often lost cell service. Without access to the phones, we were forced to rely on the car’s built-in navigation system, which was useless because it could not access GPS positioning without a phone signal.

Cargo space might be a consideration. With 12.5 cubic feet behind the rear seats, the QX55 prioritizes style over utility. This makes it ideal for weekend getaways or solo shopping trips, but not much else.

Blonde Bride and I found it cramped. Blue-eyed Beauty considers eight outfits for three days in the mountains to be roughing it.

Formidable Rivals

The 2024 Infiniti QX55, starting at $51,500, throws its hat into the ring against established players like the BMW X4 (starting at $47,450 and reaching up to $69,050 for the top-of-the-line M40i) and the Mercedes-Benz GLC Coupe (starting at $52,100 and reaching a head-turning $84,500 for the AMG GLC 63 S). All three options offer a compelling blend of performance, luxury, and a touch of practicality for the discerning driver.

While the X4’s starting price dips slightly below the QX55’s, its top trims can become significantly more expensive. The Mercedes-Benz GLC Coupe starts at a price like the QX55’s, but its AMG performance variants can soar into a completely different price bracket. 

This makes the QX55 an attractive option for budget-conscious early adopters seeking a stylish crossover with a unique driving experience without sacrificing premium features. However, they will sacrifice a great deal of residual value. Consumer Reports rates the QX55 as the least satisfying car purchase among buyers. Only 23% said they would buy another.

Safety First: A Suite of Advanced Technologies

The QX55 offers a less-than-complete suite of standard driver-assistance features, including automatic emergency braking, lane departure warning, and blind-spot monitoring. 

Our tester, which priced out at more than $60,000, had optional packages with added features like adaptive cruise control and a head-up display, 

Infiniti offers a comprehensive 4-year/60,000-mile bumper-to-bumper warranty and a 6-year/70,000-mile powertrain warranty. If you tend to hold cars for many years, bargain hard for an extended warranty.

Bottom line

The 2024 Infiniti QX55 is not for everyone. It is a niche vehicle designed for the single driver who prioritizes a luxurious and technologically advanced driving experience on the open road. For the same money, one could have a Mercedes or BMW with far more.