Infiniti Q45

Carpedia

Jan 31st, 2020

Infiniti Q45

The Infiniti brand was created by Nissan in 1989 as their luxury vehicle division to compete with Toyota’s Lexus and Honda’s Acura marques. Brought about by Japan's export restraints limiting the number of vehicles that could be exported to the US, Japanese automobile manufacturers found it was more profitable to export luxury models which are in a higher price bracket.

The Infiniti brand was launched with their flagship model, the Infiniti Q45, a four-door full-size luxury sedan with a front-engine rear-wheel-drive layout. Together with the Q45, Infiniti released a second smaller model, the two-door M30 which was a badge-engineered Nissan Leopard. The "Q" designation was a reference to the term "Q-car" which signified a vehicle with superior styling and performance.

Infiniti's naming system used one letter designating the car body style (two letters for their SUV line), with the next two-digit numbers representing the engine displacement. The "Q" was used initially for their top-of-the-line sedan models. In 2012, Infiniti announced that all sedans and coupes would carry a "Q" prefix and SUVs would have a "QX" designation. The numbers following the letter prefixes would no longer represent the engine displacement but instead would depend on the hierarchy of the models.

The Q45 was launched in Australia in 1993. However, the first generation sold poorly, prompting Infiniti to stop selling the Q45 in 1996. The Q45 continued to be sold in the US and other world markets until 2006 when it was eventually replaced. 

First Generation: G50 (1989-1996)

The first-generation Infiniti Q45 was based on the Japanese third-generation Nissan President. It was sold in Japan and other markets as the Nissan Infiniti Q45. The Q45 was impressive as it offered a high-performance engine and suspension in a luxury package. The interior was equipped with high-quality leather but with the curious absence of wood trims typically found in luxury vehicles. The wood trims would later be added in 1994. The interior received a high-end Bose sound system and several powered equipment, including seats, mirrors, steering wheel, and windows. 

The Q45 had, under its bonnet, a 4.5L VH45DE V8 petrol engine capable of producing 206 kW of power at 6,000rpm and torque of 396 Nm at 4,000 rpm, coupled to a 4-speed automatic. This engine came with forged steel crankshafts, forged steel connecting rods, 6-bolt main bearing caps with studs, and a host of other features expected from high-performing engines.

The Q45 was equipped with multi-link suspension and a viscous limited-slip differential. Acceleration from 0-100 km/h was timed at 6.7 seconds, and top speed was rated at 252 km/h. Fuel consumption was advertised at 14.2L/100km of combined city and highway driving.

The Q45 was marketed in three variants, namely, the base, Q45t and Q45a. The Q45a had a larger diameter rear stabiliser bar and full-active suspension, while the Q45t touring package included the stabiliser bar and integrated decklid spoiler. The Q45 is also credited as the world’s first production car to feature a fully active suspension with ten sensors sending its signals to microprocessor-controlled hydraulic actuators.

Second Generation: FY33 (1997-2001)

The second-generation Q45 used the Nissan President platform and shared its components with the shorter Nissan Cedric and Gloria. The Nissan Infiniti Q45 name was still used for the export market but was now badged as the Nissan Cima in Japan.

The interior was greatly enhanced with better leather and now included wood trims. Numerous standard features were added for safety and convenience, and options like reclining rear seats with massage function were available depending on the region that it was sold.

The Q45 was now powered by a smaller displacement version of the VH45DE engine - a 4.1L VH41DE V8 that was capable of producing 200 kW of power at 5,600 rpm and 377 Nm of torque at 4,000 rpm. This engine now featured the same internals as the VH45DE but with a reduced stroke. There was one major design difference between the two engines - the VH41DE was equipped with a double-row timing chain while the VH45DE was belt-driven. In Japan, the Cima was also available with a turbocharged 3.0L VQ30DET V6 (199 kW/ 367 Nm).

The second-generation Q45 could accelerate from 0-100 km/h in 7.3 seconds and had a top speed of 232 km/h. Fuel consumption was advertised at 11.8 L/100km combined city and highway driving.

It didn't follow the previous nomenclature system, which would have named it "Q41" due to its displacement. Instead, it retained the Q45 designation. In 1999, the appearance changed slightly with HID headlights being added and an analog clock replacing the old unit. It still featured the high-end Bose sound system. 

The distinguishing feature of the US models from the Japanese Cima and the Infiniti Q45 in most export markets was the absence of the hood ornament. This emblem was an acanthus leaf commonly used by classical Greeks to make a wreath that was worn as a crown.

There was also a Q45t available with a touring package that came with a decklid spoiler, heated seats, an electronically adjustable suspension system, and numerous other luxury upgrades. In 2000, the Q45 Anniversary Edition was introduced and became the highest trim model. It came with all the Q45t options.

Third Generation: F50 (2001-2006)

The third-generation Q45 was an entirely redesigned model poised as a high-performance luxury full-size sedan. The overall dimensions of the Q45 didn't change much compared to the previous but now appeared bulkier owing to its more modern styling including its Gatling gun styled headlights.

The Q45 was now powered by a 4.5L VK45DE V8 that produced 254 kW of power and maximum torque rated at 451 Nm and comes with a 5-speed automatic. This engine featured an aluminium engine block and aluminium DOHC cylinder heads with four valves per cylinder, VVT, and forged steel connecting rods.

The third-generation Q45 could accelerate from 0-100 km/h in 5.9 seconds and reach a top speed of 272 km/h. Fuel consumption is advertised at 11.8 L/100km combined city and highway driving. 

In 2003, the Q45 received a new security system and a higher final drive ratio to give a better acceleration but reduced highway fuel economy. In 2005, a facelift was done that featured new front and rear fascia together with a redesigned hood and grille, a headlamp with integrated fog lamp and LED tail lamps.

Infiniti Q45 in the Used Market

The Infiniti Q45 was not very popular in the US, Australia, and other world markets. However, it has gained quite a following these days, thanks to its combined luxury features, low price, and engine choices that are known to be durable and reliable. The VH45DE and VH41DE are becoming increasingly popular as engine transplants to the Nissan S14/S15/S16 series and also in Skyline models due to its forged internals and the ability to be turbocharged without a major overhaul. The VK45DE has also been used in its racing form to power the Nissan 350Z Super GT and is reputed to be capable of producing up to 588 kW.

If you are in the market for new or used car parts for the Infiniti Q45, visit us at Carpart.com.au, Australia's one-stop-shop for all your automotive needs. We’d be more than happy to help you.

            

Fred Cajulis