The 2006 Infiniti M45 is a quick luxury sedan for its era, powered by a 4.5-liter V8 that delivers about 340 horsepower and brisk acceleration. It isn’t a modern sports car, but it offers strong straight-line speed for a car in its class.
To understand how fast the M45 was and how it compares to its peers, this article reviews the engine and drivetrain, official performance figures, and how the car behaved in real-world driving. It also notes the differences between the rear-wheel-drive version and the all-wheel-drive M45x.
Performance specifications
Engine and powertrain
Engine size, horsepower, torque, and drivetrain configurations give a sense of the M45’s core capabilities.
- Engine: 4.5-liter DOHC V8
- Power: 340 hp at 6,000 rpm
- Torque: 333 lb-ft at 4,400 rpm
- Transmission: 5-speed automatic with manual shift mode
- Drivetrain: Rear-wheel drive (RWD) standard; all-wheel drive version (M45x) available
These figures reflect Infiniti’s aim for a powerful, refined Grand Tourer rather than a track-focused sedan.
Performance figures
Measurable pace figures such as 0-60 time, quarter mile, top speed, and weight help illustrate the M45’s speed profile.
- 0-60 mph: typically 5.3 to 5.6 seconds, depending on drivetrain and conditions
- 1/4 mile: roughly 13.9–14.5 seconds
- Top speed: governed around 149 mph
- Curb weight: about 4,000 pounds (varies by trim/options)
Real-world results varied with tires, road surface, and launch technique, but the M45 generally offered strong acceleration for its class.
In summary, the M45’s speed is solid for mid-2000s luxury sedans. It provides confident highway acceleration and robust overtaking capability without matching the immediacy or cornering aggression of a modern sports sedan.
Real-world driving impressions
On the road, the M45 prioritizes smoothness and refinement. The 4.5-liter V8 delivers strong midrange torque, which helps with effortless passing and merging. The 5-speed automatic shifts smoothly, and the available manual shift mode gives a touch more control. However, the car’s substantial weight and rear-drive bias can make it feel less nimble than smaller sport sedans, and steering feedback is not as tight as contemporary performance-focused cars.
Before lists and numbers, it’s helpful to know that the M45 was designed as a luxury cruiser with performance-grade power, not a modern-day sports car. Its strengths lie in power delivery, ride comfort, and long-distance capability rather than razor-sharp cornering.
Bottom line: Is it fast?
Yes. By 2006 standards, the Infiniti M45 was a fast, potent sedan, especially in its RWD configuration. It accelerates briskly, moves decisively at highway speeds, and provides a satisfying level of performance for a luxury sedan of its era. It isn’t a current-day performance car, but it offered strong speed with a refined, comfortable ride that appealed to buyers seeking luxury with noticeable, usable power.
Summary
The 2006 Infiniti M45 combined a 340-hp V8 with a 5-speed automatic, delivering 0-60 times in the mid-5-second range and quarter-mile times in the high-13s to low-14s. Its performance was competitive for its class in the mid-2000s, particularly in configurations with rear-wheel drive, and it remains a notable example of Infiniti’s V8-powered luxury performance approach from that era. Today, it stands as a fast, comfortable grand tourer rather than a modern performance benchmark.