Sunday, April 22, 2007

Toyota 4Runner

3rd-gen Toyota 4Runner
Manufacturer Toyota

The Toyota 4Runner is an SUV manufactured by Toyota and sold mainly in the United States, Canada and Mexico from 1984 to the present. The original 4Runner was a compact SUV and a little more than a Toyota pickup truck with a fiberglass shell over the bed, but the model has since undergone significant independent development into a mid-size SUV. All 4Runners have been built at Toyota's plant in Tahara, Aichi, Japan as well at Hino Motors' Hamura, Japan plant.

Pre-1984 Toyota Trekker, was available in two or four wheel drive. In a slightly different approach, Griffith started with a complete pickup, cutting the back of the cab out, sealing the gap between the cab and bed, and attaching a permanent camper shell. Rear seats were also added. Griffith called the vehicle the TrailBlazer, and the third company sold theirs as the Wolverine. All of the vehicles were made in relatively small numbers and few remain in existence today.

First generation (1984–1989)

First generation
Toyota 4Runner
Production 1984–1989
Body style(s) 2-door SUV
Engine(s) 2.4 L 22R I4 (1984-1986)
2.4 L 22R-E I4 (1985-1989)
22R-TE I4 (1986-1988)
3.0 L 3VZ-FE V6 (1988-1989)
2.4 L 2L-T turbodiesel I4
Wheelbase 103.0 in.
Length 174.6 in.
Width 66.5 in.
Height 66.1 in.

The Toyota pickup (upon which the 4Runner was originally based) underwent a major redesign in 1983 for the 1984 model year. Many other automakers were introducing mid-size SUVs in the mid 1980s (e.g., Ford Bronco II, Chevrolet S-10 Blazer) and the pressure mounted on Toyota to develop a competing model. Instead of developing an entirely new model, Toyota took their existing short-bed pickup frame, made some simple modifications, and added an open one-piece body with a removable fiberglass top (much like the full-size Ford Bronco and Chevrolet K5 Blazer).

Thus, the first generation 4Runner is nearly mechanically identical to the Toyota pickup. All first generation 4Runners had two-doors and were indistinguishable from the pickups from the dashboard forward. Nearly all changes were to the latter half of the body; in fact, because the rear springs were not upgraded to cope with the additional weight of the rear seats and fiberglass top, these early models tend to suffer from sagging rear suspensions.

The first 4Runners were introduced in 1984 as 1984 1/2 models. For this first year, all models were equipped with black or white fiberglass tops. An SR5 trim package was offered that upgraded the interior: additional gauges, better fabrics, and a rear seat were standard with the package. All 1984 models were equipped with the carbureted 2.4 L 22R engine and were all available with a four wheel drive system that drove the front wheels through a solid front axle (although this would be changed in 1986).

1985 saw the advent of the electronically fuel-injected 2.4 L 22R-E engine (though the carbureted engine remained available until 1988). Additionally, rear seats were available in all 1985 4Runner trim levels, not just the SR5.

In 1986, all American-market Toyota pickup trucks (and the 4Runner) underwent a major design change as the suspension was changed from a solid front axle to an independent front suspension. This change for the American market made the trucks more driveable at highway speeds and increased the space in the engine compartment, but arguably decreased the truck's off-road capabilities. It also widened the track of the truck by three inches, making it more stable in turns. Outside the US, the Hilux Surf also gained the new Hi-Trac suspension design, though the pickups retained the more rugged and capable, if less refined, solid axle configuration. Tops were color-matched on blue or red 4Runners, while other body colors were still sold with white or black tops. During 1986 many 4Runners were imported to the US without rear seats. With only two seats the vehicle could be classified as a truck (rather than a sport vehicle) and could skirt the higher customs duties placed upon sport and pleasure vehicles. Most had aftermarked seats and seat belts added by North American dealers after they were imported.

A turbocharged version of the 22R-E engine (the 22R-TE) was also introduced in 1986, although this engine is significantly rarer than the base 22R-E. It appears that all turbocharged 4Runner models sold in the US were equipped with an automatic transmission, though a five-speed manual could still be ordered in the turbocharged pickups. Most Turbo 4Runners were equipped with the SR5 package, and all turbo trucks had as standard a heavier rear differential (which would show up again in 1988, when the V6 engine was introduced). Low-option models had a small light in the gauge cluster to indicate turbo boost, while more plush vehicles were equipped with an all-digital gauge cluster that included a boost gauge. Turbocharged and naturally aspirated diesel engines were also available in the pickups at this time as well, but it appears that no diesel-powered 4Runners were imported to the United States.

In 1988, the 22R-E engine was joined by an optional 3.0 L V6 engine, the 3VZ-E. This engine was significantly larger and more powerful than the original 4-cylinder offering. Trucks sold with the V6 engine were equipped with the same heavy duty rear differential that was used in the turbocharged trucks, as well as a completely new transmission and transfer case; the transfer case was chain driven, and created less cab noise than the old gear-driven unit used behind the four cylinder engine.

Small cosmetic and option changes were made in 1989, but the model was left largely untouched in lieu of the replacement model then undergoing final development.

Second generation (1990–1995)

Second generation
1990-1995 Toyota 4Runner
Production 1990–1995
Body style(s) 4-door SUV
2-door SUV
Engine(s) 2.0 L 3Y I4
2.4 L 22R-E I4
3.0 L 3VZ-E V6
2.4 L 2L-TE turbodiesel I4
2.8 L 3L diesel I4
3.0 L 1KZ-TE turbodiesel I4
Wheelbase 103.3 in.
Length 176.0 in.
Width 66.5 in.
Height 66.1 in.
2-door Toyota 4Runner
2-door Toyota 4Runner

The 1989 model year 4Runner represented a fundamental departure from the first-generation model. Instead of an enhanced pickup truck, the new 4Runners featured a freshly designed body mounted on an existing frame. The difference is easily seen when comparing pickups and 4Runners of similar vintage: a 1984 4Runner looks remarkably similar to a 1984 Toyota pickup, whereas a 1990 4Runner shares only subtle styling details with the 1990 pickup.

Nearly all second generation 4Runners were 4-door models, however from 1989 to 1992, a 2-door model was also produced. These models are similar to the 4-door models of the time in that the bodies were formed as a single unit, instead of the fiberglass tops used in the first-generation 4Runners. Two-door 4Runners from this era are extremely rare, and were discontinued in August 1992, probably due to higher importation duties and owner insurance costs.

Because the drivelines were still developed from the same source, however, available engines were identical. A new 2.4 L four cylinder and the same 3.0 L V6 were both available in rear wheel drive and four wheel drive layouts. The new 4Runner used the independent front suspension that had been developed on the previous generation. The older style gear driven transfer case was phased out, and both engines now had chain driven cases, probably to cut down cab noise and vibration.

The Hilux Surf version for the Japanese market was also available with a range of diesel engines, including a 2.4 L turbodiesel 2L-TE I4 up to 1993, followed by a 3.0 L turbodiesel 1KZ-TE I4. A small number were also made with a normally aspirated 2.8 L diesel 3L I4. A small number were also produced with a 2.0 L 3Y I4 naturally-aspirated gasoline engine.

Most other full-body SUVs produced at the time (e.g. Nissan Pathfinder, Ford Explorer) featured tailgates that opened upward with the glass closed. In contrast, the second generation 4Runner carried over the retractable-glass tailgate from the first generation. Opening these tailgates requires first retracting the rear window into the tailgate and then lowering the tailgate much like as on a pickup truck.

In 1992, the 4Runner received minor cosmetic updates, including modular headlamps instead of the increasingly outdated rectangular sealed beams. Additional cosmetic changes occurred between 1993 and 1995, the last year of the second generation.

Third generation (1996–2002)

Third generation
Toyota 4Runner
Production 1996–2002
Body style(s) 4-door SUV
Engine(s) 2.7 L 3RZ-FE I4
3.4 L 5VZ-FE V6
3.0 L 1KZ-TE turbodiesel I4
Wheelbase 105.3 in.
Length 183.2 in.
Width 70.9 in.
Height 67.3 in.

1996 marked another significant redesign of the then-aging 4Runner. Whereas the transition to the second generation 4Runner was one that kept the build quality and options roughly on par with the rest of the mid-size SUV market, the changes made in the third generation turned the 4Runner into a more luxury-oriented vehicle. This move paralleled the upgrades to the 1996 Nissan Pathfinder, but moved the 4Runner into a distinctly different class than its older competitors, the Ford Explorer, Chevrolet Blazer, and Isuzu Rodeo. The third generation 4Runner did, however, look very similar to the second generation.

This similarity largely ended with its looks. It carried over the basic design and concept, but executed it differently with an all-new bodyshell on an all-new chassis. This time, it shared virtually nothing with the pickup it had originally evolved from, and had more in common with the Land Cruiser, as it shared its chassis with that of the Land Cruiser Prado. The third generation 4runner also featured new engines, a 2.7L 3RZ-FE I4 replacing the previous 2.4L 22R-E I4, and a 3.4L 5VZ-FE V6 replacing the previous 3.0L 3VZ-E V6. Both of these new engines are also found in the first and second generation Toyota Tacoma pickup trucks.

Significant changes from the second generation models include a larger body on a longer wheelbase, increased interior space, increased cargo space, twin airbags, ABS, lift-up tailgate, coil-sprung suspension all round, rack and pinion steering. Additionally, Hilux Surf versions immediately moved to 16 in wheels and gained a center differential, enabling the use of four wheel drive on hard surfaces without complication for the first time. The prior system was retained to give on-the-fly shifting between rear and four wheel drive as before.

Fourth generation (2003–present)

Fourth generation
4th-gen Toyota 4Runner
Production 2003–present
Body style(s) 4-door SUV
Engine(s) 4.0 L 1GR-FE V6
4.7 L 2UZ-FE V8
Wheelbase 109.8 in.
Length 189.2 in.
Width 72.2 in.
Height 68.1 in.

The fourth generation 4Runner incorporated serious changes to the chassis and body of the vehicle, but was targeted at approximately the same demographics as the third generation. Based on the Land Cruiser Prado 120 series, the updated 4Runner looks very different from the older 4Runners, but is still targeted as a mid-size quasi-luxury SUV. Available trims are currently the SR5, Sport Edition, and the Limited. An all-new 4.0 L 1GR-FE V6 is standard in the current 4Runner, but for the first time, a V8 became available for the fourth generation models. It cranks out 260 horsepower and 306 lb-ft torque. The same 4.7 L 2UZ-FE V8 found in the Land Cruiser, Tundra, and Sequoia is now an available option for the fourth generation.

When it was first introduced for the 2003 model year, the SR5 and Sport Edition models used gray plastic cladding and bumpers. In early 2003, Toyota added an optional Appearance Package for the SR5 model that included color-keyed cladding, bumpers, and liftgate trim. In April 2003, Toyota made the Appearance Package, along with the previously optional fog lamps, running boards, and 16" alumnimum wheels, standard on the SR5. The Sport Edition also added black running boards and color-keyed trim, replacing the grey cladding and silver-painted grill, door handles and liftgate trim.

In 2004, a tire pressure warning system was added as standard equipment. A 3rd row seat became optional on the SR5 and Limited models.

The 2005 model brought enhancements to the optional V8 engine and made a 5-speed automatic standard on the V6 model. Slight changes were made to the exterior including color-keyed bumper trim (replacing the silver painted trim on all colors except Dorado Gold) on the SR5 and Limited; a chrome grill on the SR5; a black roof-rack and running boards (replacing silver) on the Limited; and a redesigned rear spoiler.

Facelifted 2006 Toyota 4Runner
Facelifted 2006 Toyota 4Runner

The 2006 model year marked the fourth generation's mid-cycle refresh. The changes included revised front and rear bumpers; a reworked grill; new projector-beam headlamps and LED tail lamps; additional chrome trim on the SR5 model; and a smoked-chrome grill with tubular roof-rack and step bars on the Sport Edition. The revised front bumper features circular fog lights and a relocation of the turn-signals to the headlamp assembly. The redesigned bumper eliminates the rear bumper reflectors. MP3 playback capability and an auxiliary input jack were added to all audio systems. In addition, the Limited model was further differentiated from the trim levels with the addition of unique 18" wheels and a seat memory system.

For 2007, the 4Runner is essentially unchanged.

Safety

Both the first and second generation 4Runners became targeted as very unsafe SUVs. 1980s and early-1990s US crash regulations were not very strict for light trucks, and all early model 4Runners were fitted with doors that offered little protection in the event of a side collision. In most areas, there was little more than two pieces of sheetmetal and the window to keep incoming vehicles from impacting passengers.The crash test rating for the second generation 4runner was one star for the drivers side in a frontal collision although the passenger side got a 4 star rating. Later, more stringent crash regulations mandated doors that offered as much protection as passenger car doors.

The most common accusations, however, were that 4Runners (and other narrow-track SUVs of the time) were prone to rollovers. Many light SUVs of the time featured comparatively high centers of gravity and, given the right situations, could be flipped over. Whether or not this is a serious road hazard is dependent on many parameters including the speed of the vehicle, the tires fitted to the vehicle, the road surface, and the driver's ability to predict and correct for situations that may result in a rollover. Third generation 4Runners were designed with a wider track, but it is unclear if this was directly in response to increased pressure from safety groups, or if it was simply a product engineering decision.



1 comments:

Caleb said...

nice post! i love how you presented toyota 4runner over the years. im actually preparing a paper on car evolution and your post has been turly helpful. the specific of each version is what im actually looking for in particular. thanks!