Ultimate Toyota 1GZ FE Engine Guide - Total Specs & Basic Info (2024)

In terms of Toyota’s many engines, the 1GZ-FE truly stands alone amongst its peers. A 5.0 liter, naturally aspirated, V12 engine, the 1GZ is truly a whole other animal from Japan. It’s Toyota’s only production V12 in history, and it’s the second largest engine behind the 5.7 liter 3UR-FE V8. While the 1GZ will never be as well known or reach the heights of the much more popular 1JZ-GTE or 2JZ-GTE motors, enthusiasts will forever remember the 1GZ for its uniqueness and excellent power delivery. The 1GZ FE produces incredible low-end power, making as much as 295 lb-ft of torque by just 1,200 RPM. Today, let’s take a look back at Toyota’s 1GZ-FE V12 engine and all its former glory.

Toyota Century 5.0 V12 History

Toyota first introduced the 1GZ-FE engine for the 1997 model year, and they kept it in production through 2017. They only put the engine in one model, the Toyota Century: A full-sized limousine, luxury, and executive car. The Century was quite popular among government officials throughout the world, including in Europe, the Middle East, and China. Only one made its way stateside — for testing purposes only — and The New York Times compared it to the Mercedes Maybach.

Though it was a 5.0 liter V12 engine — massive by ‘90s Japanese auto standards — power output was still modest. In Japan, Toyota rated the engine at 276 horsepower and 355 lb-ft of torque. However, this partly reflects the “Gentlemen’s Agreement” amongst Japanese auto manufacturers. This was an agreement not to sell production cars with more than 280 horsepower. Toyota rated the engine at 295 horsepower for export, and it’s believed the actual number is north of 300 horsepower, even on domestic versions.

In 2010, due to increasing emissions regulations, Toyota slightly changed the programming for the engine. This resulted in a drop of torque from 355 to 339 lb-ft, though the engine was otherwise the same.

To date, the 1GZ FE is the only V12 engine that Toyota has built. It’s their second largest to only the 5.7 liter 3UR-FE V8 engine, and was the largest ever until the 3UR came out in 2007. In 2017, Toyota stopped producing the engine, and they have not brought another V12 back onto the market since.

Toyota 1GZ FE Specs

Toyota 1GZ-FE Vehicles

The Toyota 1GZ-FE V12 engine appeared in the following vehicles:

• 1997–2017 Toyota Century
• 2006–2008 Toyota Century Royal

Toyota only put the 1GZ FE engine inside a single model, the Toyota Century. That also means they used it in the 2006 Toyota Century Royal (G51 series). The Century Royal was the official state car of the Emperor of Japan from the 1960s all the way until 2008. In 2009, Japanese officials replaced it with the Lexus LS. The 1GZ-FE was the last engine put inside the Century Royal. The Emperor used it for two years until its replacement from 2006–2008.

Toyota 1GZ-FE Design Basics

Toyota 5.0 V12 Block, Heads, and Internals

Now let’s talk about the design of the Toyota 1GZ V12 engine. For starters, it is a 5.0 liter (4,996 cc) 60° V12 engine that is naturally aspirated. Both the engine block and cylinder heads are aluminum, helping the engine reduce weight while still maintaining adequate strength. The engine’s bore and stroke are 81 mm x 80.3 mm, making it almost a perfectly square engine. The heads sit at a 60° angle and are Toyota’s “Economy Narrow-Angle” style. That means Toyota designed them for efficiency and fuel economy over high performance.

Toyota’s 1GZ-FE engine code is pretty basic and breaks down as follows:

• 1 – 1st Generation Engine
• GZ – Toyota GZ Engine Family
• F – Economy Narrow-Angle DOHC Cylinder Heads
• E – Multi-Point Fuel Injection

The Toyota 1GZ-FE is one of two engines in the GZ family, with the other being the 1GZ-FNE. The only difference between the two is the FNE version runs on compressed natural gas (CNG) instead of petrol/gasoline like the FE.

Internally, Toyota used a counterweighted, forged steel crankshaft. The pistons are aluminum and the connecting rods are forged steel, making the internals of the 1GZ extremely stout — which they had to be to keep up with the demand of the engine’s low-end torque. Compression sits at a static 10.5:1.

Toyota 5.0 V12 Valve Train & More

Toyota’s 1GZ FE engine is a dual-overhead camshaft design, and they use timing chains to operate the cams. There are 4-valves per cylinder, making the 1GZ a 48-valve engine. The engine does utilize variable valve timing, but only for the intake valves (VVT-i).

For the intake, the manifold is a variable-runner design that helps keep torque strong throughout the entire RPM range. The 1GZ uses dual throttle bodies, one that feeds each cylinder bank. The throttle bodies are fly-by-wire operated, which means they use sensors instead of a cable like older models. As indicated by the E in the 1GZ-FE engine code, the engine utilizes electronic fuel injection for fueling.

Additionally, Toyota used both dual ECUs and dual fuel pumps. They used one ECU per cylinder bank. This allows the engine to function somewhat in the event that one cylinder or bank fails. For the dual fuel pumps, Toyota created an advanced system that switches the pump being used each time the ignition is cycled. This means that even if one of the pumps fails, another ignition cycle switches to the other pump. Again, this allows the engine to start if at least one pump and one cylinder bank still functions.

Toyota created these failsafes with the ECUs and fuel pumps so that no driver would ever be left stranded by the 1GZ. It worked extremely well, and the 1GZ became one of Toyota’s most reliable engines even though it was relatively low on their production scale.

Toyota 5.0 V12 Reliability and Problems

Overall, many consider the Toyota 1GZ-FE to be an extremely reliable and stout engine. However, that does come with somewhat of a caveat. Toyota only produced the 1GZ engine in relatively small numbers for the Toyota Century, so they built only a limited number each year — though production did last for two full decades.

In addition to their not being a ton of 1GZs built, they were also relatively underpowered from the factory, making just 276 horsepower and 355 lb-ft of torque at its most powerful. That’s not a huge power output for such a large (by Toyota’s standards) engine, meaning that most of the internals are relatively unstressed at stock power levels.

The only true “problems” that have crept up with the 1GZ FE are oil consumption and electrical wiring shorts. Oil consumption is a common problem on engines past 100,000 miles, though it does not seem to be too excessive. It has also been said that the early years of the 1GZ were plagued by electrical issues with the throttle bodies, ECU, and other sensors. However, this was largely corrected from 2000-on, and was not a widespread problem.

Overall, the 1GZ is a very reliable and sturdy engine and can easily go more than 200,000 miles without needing a rebuild. The engine’s strong internals and modest power figures help it achieve stunning longevity, and many G50-series Centuries are still using their original 1GZ V12 engine with little to no problems.

Toyota 1GZ FE Performance and Ultimate Builds

If there is one area that the 1GZ-FE engine is lacking in it’s performance. While 276 horsepower isn’t exactly nothing, especially by late-1990s standards, it’s a bit underwhelming inside such a large package like a 5.0 liter V12. However, the 1GZ does somewhat make up for it by having unbelievable low-end torque. The 1GZ is pumping out nearly 300 lb-ft by just 1,200 RPM, which is pretty incredible for a non-Direct Injected engine.

Much of its lesser performance had to do with the so-called “Gentlemen’s Agreement” amongst Japanese auto manufacturers in the 1990s. This agreement capped horsepower at 276 horsepower for all domestic production cars in an effort to help fight climate change. It’s widely accepted that in several cases, however, like the 1GZ, Toyota merely rated the engine at 276 horsepower for marketing purposes (it was 295 horsepower on exports to Australia, Europe, and China).

Many experts believe the real number was much higher, closer to 300+ horsepower according to some sources. Still, even at 300 horsepower or just above, that’s not very much for such a big (by Toyota’s standards) engine with so many cylinders. Considering the 3.0 liter 2JZ-GTE was released six years earlier than the 1GZ and made 320 horsepower in export markets, it’s fair to call the 1GZ underpowered.

Toyota 1GZ-FE Ultimate Builds

While it doesn’t have a huge aftermarket, there are still many exceptional 1GZ FE builds out there, including some that make some incredible horsepower numbers.

On this build, Jaron Olivecrona built a 750 horsepower 1GZ using parts from Hartley’s Performance. Olivecrona uses it as a drift car, and goodness does it sound glorious around the track.

Another popular build is from legendary Japanese tuner and engine builder Smokey Nagata. Smokey’s 1GZ powered Toyota Supra is one of the most famous 1GZ builds ever, and he used it when doing his record breaking 0-300 km/h run on the Wangan Highway in Japan back in the late-1990s.

Finally, we have another build using Hartley Performance products. This one makes an astonishing 1,000 horsepower and revs all the way out to 10,000 RPM. It might just be the highest horsepower 1GZ build ever, and it absolutely rips at the track.

Toyota 1GZ-FE Summary

Toyota’s 1GZ FE engine was a remarkably solid 5.0 liter V12 that lasted for 20 years from 1997–2017. While the engine only produced 276 horsepower and 355 lb-ft of torque, it delivered exceptional low-end torque and was still quite pleasant to drive. Most experts consider the engine to actually make 300+ horsepower, and claim its rating was only due to Toyota’s informal “Gentlemen’s Agreement.”

In addition to being a fun ride, the 1GZ was also incredibly reliable to boot. There are really no common problems or big flaws, with the exception of oil consumption, which happens on basically any high-mileage engine. The 1GZ is capable of going extreme mileages without a rebuild, and they were solid enough they even chauffeured the Japanese Emperor around for a few years in the mid-2000s.

Toyota 1GZ-FE FAQ