Overview

Standard equipment on the M30 included a driver's side airbag, anti-lock brakes, an anti-theft security system with an engine immobilizer, Nissan Sonar Suspension II, and leather upholstery. Other standard features include a 4 speaker Nissan-Bose audio system with satellite radio controls, a cassette player and an electric mast antenna, cruise control, power windows, power door locks, power mirrors, power moonroof, and on coupes, automatic climate control.

For the 1991 model year, the cable-type speedometer became electric, instrument cluster typeface changed to match that of the Q45, and fuel and coolant temperature gauges were switched. An illuminated entry feature was added that would light the driver's and passenger's door keyhole and the interior dome light upon pulling the outer door handle. Selective door lock logic was added that allowed unlocking of the passenger door from the driver's keyhole by turning the key twice.

A convertible was introduced for the 1991 model year. All convertibles originated as coupe models, and were shipped to California and converted by American Sunroof Corporation (ASC). The electric canvas top featured fully automatic push-button operation, similar to the redesigned 1990 Mercedes-Benz SL, although the SL used a hydraulic system. Unlike the coupe, the M30 convertible use manual climate controls, and a Bose Active Sound audio system. The convertible top used a plastic rear window; as a result the rear window defrost feature used on the coupe was removed, and buttons to raise and lower the convertible top were put in place of the rear window defrost switch. The convertible model was never officially sold in Japan, and was exclusive to the US market, although convertibles have been imported to Japan in the last few years by collectors.

All 1992 models gained the addition of a central locking switch next to the Sonar Suspension II selector, and the intake plenum cover was revised and displayed the Infiniti logo, rather than the Nissan logo and the "V6 3000" script on 1990 and 1991 cars.

The M30 was discontinued after the 1992 model year following a production run of approximately 17,000 cars. It was replaced in the Infiniti lineup by the J30 sedan, which was based on the F31 Nissan Leopard's successor, the Nissan Leopard J. Ferie (chassis code Y32).

Technical

Power came from Nissan's VG30E V6, which produced 162 hp (121 kW; 164 PS) at 6000 rpm, and 180 lb⋅ft (244 N⋅m) of torque at 3500 rpm. All M30s had a Jatco RE4R01A 4-speed automatic transmission. The differential was a Nissan open R200 unit. Although most Nissan Leopards were equipped with a DOHC V6, offered in 2-liter, 3-liter, naturally aspirated, turbocharged variants, the M30 was only offered with the SOHC VG30E. Although it was a smooth powertrain, which Infiniti touted in its brochures for the M30, the 3,302 lb (1,498 kg) coupe, and 3,523 lb (1,598 kg) convertible were generally received as overweight and underpowered, with a quoted 0–60 time of 9.4 and 9.7 seconds, respectively. Infiniti marketed the car as a luxury sports coupe. Still, its relatively low power output, comfort-oriented driving dynamics, and the absence of a manual transmission, which was offered only in Japan, hampered its performance and sporting image.

Like the Nissan Maxima, the M30 was equipped with Nissan's Sonar Suspension II, using a multi-link suspension for the front wheels. A sonar sensor mounted underneath the front bumper scanned the road surface ahead of the vehicle. It instantly changed damping based on varying road surfaces, using individual actuators on all shock absorbers. A center console-mounted switch allowed drivers to choose between Comfort (soft) and Sport (firm) suspension modes. Vehicles not installed with the adjustable suspension were installed with MacPherson struts for the front wheels and semi-trailing arm with 4-links for the rear.

Reception

The automotive press the Y50 Infiniti M several praised the M35 and M45's driving involvement and handling dynamics vs the GS and E-Class while having superior ergonomics to the 5 Series; furthermore the M was equipped and priced competitively against its German rivals,^[11][12] while the M35 also received strong reviews.^[13] Despite entering a very crowded, competitive segment in which almost every member has been recently redesigned, the M managed to claim several key distinctions. The M is near or at the top of its class of every interior dimension, actually breaking into the United States Environmental Protection Agency "large" category depending on which option packages are selected. ^{[14] [15] [16]} The M35x won Consumer Reports top luxury car pick for 2006, taking the top spot from the 2005 Lexus LS 430.

The Infiniti M did not gain a significant share in the mid-luxury market. The Infiniti G37 sedan and coupe, competing in the entry-level luxury sport category, accounted for half of the marque's sales as of 2009.^[17] Out of that year's 81000 Infiniti cars sold, only 10000 were of the M nameplate.^[18] Furthermore, the 2009 update left M35 and M45 in awkward positions of the Infiniti lineup, as though they were the flagships of the marque, they were out-powered by the VQ37VHR engines fitted in the 2009 G37 coupe and sedan. For that model year while the G Series received 7-speed automatic transmissions across the lineup, only the M35 RWD was upgraded to a 7-speed automatic while the rest of the nameplate retained the aging 5-speed automatic.^[19]

2008/2009 Mid-generational refresh

For the 2008 model year, the Infiniti M received a facelift, receiving optional all wheel drive (M45x), revised front and rear fascias, revised tail lights, and redesigned blue-highlted gauges, previously orange. Infiniti also offered an S type version for the M45/M45x similar to the previous Sport model. Other new features on the 2008 model include touch screen hard drive based navigation, iPod integration, and a music hard drive.

For 2009, the M35 received a new V6 engine producing 303 hp (226 kW) and 262 lb⋅ft (355 N⋅m) of torque and a 7-speed automatic transmission. The 2009 M35x, M45, and M45x retained the five-speed automatic.^[20]

Safety

The third generation Infiniti M models were given a "Top Safety Pick" by the Insurance Institute for Highway Safety (IIHS) by earning a "Good" score for all four IIHS crash tests while also featuring standard stability control to help avoid accidents altogether.

Engines

M35h (Hybrid version) (2011–2019)

The Infiniti M Hybrid, sold as the Nissan Fuga Hybrid in Japan where it was the top performance trim, introduced Nissan's first in-house developed electric hybrid technology, and the carmaker claimed it doubles the fuel economy of its gasoline-powered version.^[27] Nissan also announced that the Nissan Infiniti/Fuga Hybrid, together with the Nissan Leaf, included its new Vehicle Sound for Pedestrians system to alert pedestrians, the blind and others to their presence when the hybrid is operating at low speeds in all-electric mode.^[28][29]

The hybrid includes one electric motor and two clutches to allow the 3.5L V6 (302 hp (225 kW) and 258 lb⋅ft (350 N⋅m)) gas engine and electric motor to drive the rear wheels simultaneously. The lithium-ion battery pack comes from the Infiniti Essence.^[30] The VQ35HR 3.5 L V6 Hybrid utilizes the Atkinson cycle. The electric motor, installed in parallel between the engine and the transmission, produces 68 PS (50 kW; 67 bhp) from 1.3kWh lithium-ion batteries that are expected to have a service life of 10 years. The batteries are installed upright behind the rear seats. The main sacrifices are that the luggage compartment space is reduced, the hybrid's rear seats are fixed in place and cannot fold down, and all-wheel drive is not available.^[27] One benefit of the battery placement though, is that it leaves the hybrid with a 51/49 front to rear weight distribution.

The combined power output of the M35H's hybrid power-train is 360 hp (268 kW; 365 PS) at 6500 rpm, and an estimated 391 lb⋅ft (530 N⋅m) of torque at 2000 rpm.^[31]

Reviewers have considered the 2012 Infiniti M35h, along with the 2011 Porsche Panamera S Hybrid which also debuted in the same calendar year, as among the best executed hybrid performance luxury cars. The M35h and Panamera S Hybrid are the first hybrid gasoline-electric vehicles with an automatic transmission to return frugal fuel economy figures and retain the acceleration/handling characteristics of its gasoline-only counterparts. Earlier hybrids such as the Lexus 2007 GS 450h used a CVT for fuel economy at the cost of driving dynamics, while the 2010 BMW ActiveHybrid 7 which has an automatic transmission did not feature significantly improved mileage over its gasoline counterpart.^[32][33] The M35h's fuel economy is superior to the M37, and it is almost as fast as the M56 while providing a more balanced, near 50/50, front/rear weight distribution.^[34]

On August 23, 2011, the Infiniti M35h set an official Guinness world record for the world's fastest accelerating production full hybrid. The feat took place at the United Kingdom's Santa Pod Raceway, where CAR magazine journalist Tim Pollard drove the vehicle down the quarter-mile dragstrip in 13.896 seconds. The M35h averaged 13.9031 seconds for all runs, reaching speeds over 100 mph (160 km/h). Guinness adjudicators were present to witness the run and certify the record.^[35][36] The official claimed 0–100 km/h (62 mph) time for the Infiniti M35h is 5.5 seconds.

M30d (Diesel version) (2010–2014)

In 2010, at the Geneva Motor Show, the Infiniti M was introduced with a diesel engine for the first time. It was sold across Europe starting in September 2010. The V9X diesel engine produces 240 hp (179 kW) and 406 lb⋅ft (550 N⋅m) of torque at 2,500 rpm. In western Europe, this V6 performance diesel was offered as a high performance option in lieu of the M56 V8. The M30d was not sold in the US or Canada.^[37]