The Evolution of the Toyota UZ Engine (Explained)

If you’re familiar with some of the stuff we cover on this channel, you probably know that engines typically come in families. Typically an engine is developed and then the manufacturer changes that first engine to suit new platforms or applications, and this is the case with pretty much all Toyota engines.

The Toyota UZ engine family is one of the more popular V8 engine families that Toyota ever made, and today we’re going to take a deep look at the UZ engine family, including the 1UZ-FE, 2UZ-FE, and 3UZ-FE. Grab your popcorn and let’s get started.

1UZ-FE

So, let’s start with the 1UZ-FE, which is the first engine in the Toyota UZ family. Toyota designed this new 4.0L V8 to replace the outdated Toyota 5V. If you didn’t already know, the 1UZFE was a pretty advanced engine when it came out. Very few V8’s at the time were dual over head cam, with 32 valves, and actually reliable.

The 1UZFE is arguably the first ever reliable Japanese DOHC V8, and definitely one of the greatest. Although, you can argue that some of Nissan’s V8 offerings from the time were just as good or better.

Starting with the basics, the cylinder block of the 1UZ-FE is made from cast aluminum and uses a 90* design. The cylinder heads are also made of aluminum, making the total package fairly lightweight for such a physically large engine, because you have to remember that putting massive dual overhead cam heads on a 90* V8 doesn’t exactly make a tightly packaged engine.

A random side note is that the 1UZFE doesn’t have hydraulic lifters. Instead, it uses a shim over bucket design so it needs periodic valve adjustments.

Later versions of the 1UZFE received Toyota’s VVT-i system, which improved horsepower and fuel economy. A nice feature about the 1UZFE is that if the timing belt breaks, the valves will not interfere with the pistons. A broken timing belt won’t cause your engine to self-destruct.

  • Production: 1989-2002
  • Cylinder Block Material: Aluminum
  • Cylinder Head Material: Aluminum
  • Valve train: DOHC, 4 valves per cylinder
  • Stroke: 82.5mm
  • Bore: 87.5mm
  • Compression Ratio: 10:1 – 10.5:1 (VVT-i)
  • Displacement: 3969cc
  • Redline: 6,200 – 6,500 rpm (VVT-i)
  • Weight: 364 lbs

The 1UZFE came in a variety of Toyota cars, ranging from sports cars to luxury cars. Toyota equipped the 1UZ in the Lexus GS400, LS400, and SC400. The 1UZFE was also equipped in the Toyota Aristo, Celsior, Crown, and Soarer. I owned an SC400 for a while and loved how to engine felt in that car.

  • Lexus GS400
  • Lexus LS400
  • Lexus SC400
  • Toyota Aristo
  • Toyota Celsior
  • Toyota Crown
  • Toyota Soarer

Like I mentioned before, the 1UZFE has come in a couple different forms over the years. Engine changes such as VVT-i increased the horsepower. It started at 256 horsepower and 260 ft-lbs. Then Toyota added high compression pistons which bumped power up to 261 horsepower and 269 ft-lbs. The addition of VVT-i bumped it up to 290 horsepower and 300ft-lbs. The final version of the 1UZ received minor revisions which increased power to 300 horsepower and 310 ft-lbs.

  • 256 horsepower @ 5,400 rpm
  • 260 lb-ft of torque @ 4,400 rpm
  • Toyota added higher compression ratio pistons
  • 261 horsepower @ 5,400 rpm
  • 269 lb-ft of torque @ 4,400 rpm
  • Toyota developed their VVT-i to work on the 1UZFE
  • 290 horsepower @ 5,900 rpm
  • 300 lb-ft of torque @ 4,100 rpm
  • Toyota added a few revisions
  • 300 horsepower @ 6,000 rpm
  • 310 lb-ft of torque @ 4,000 rpm

As you might be able to tell from these numbers, the VVT-i system worked wonders of the 1UZFE. The VVT-i system added 34 horsepower, and 40 lb-ft of torque over the original version. Most notably, the VVT-i system brought the peak torque down 400 rpm, making the car much more fun to drive around the street.

How can this engine be tuned to make more horsepower than factory? Well, naturally aspirated builds can reach as high as 400 horsepower, but costs a fortune, and is hard to build.

The Terminator Cobra supercharger or Eaton M90 is a common addition the 1UZFE. With additional changes such as fuel injectors and an exhaust, the 1UZFE can make 350+ horsepower @ 6 psi. Building the bottom end with lower compression ratio pistons, the 1UZFE can make 400+ horsepower @ 10 psi.

Turbo kits are available for most cars that came equipped with the 1UZFE, but they need a built bottom end to survive. Much like other great Toyota engines (1JZ, 2JZ, etc.), the stock 1UZFE block is good for pretty crazy amounts of power.

Nissan’s VH45DE was the only real competitor to the 1UZ-FE. They both used dual overhead cams, both have a displacement of less than 4.6L, both came from Japan, and both were designed for luxury cars.

The VH45DE made a pretty impressive 278 horsepower and 294 lb-ft of torque. But that is less than the 1UZ made in it’s final versions. Like I mentioned above, the 1UZ made 300 horsepower and 310 lb-ft of torque at its best. That’s 22 horsepower and 16 lb-ft more than the VH45DE, while also being .5L smaller in displacement.

2UZ-FE

Moving on the to 2UZ-FE, it’s the second in the Toyota UZ family. It came after the 1UZ-FE and before the 3UZ-FE. The 2UZ is based off the 1UZ, but it was designed for use in trucks and SUVs instead of sports cars and luxury cars.

With the application being vastly different, Toyota needed to majorly change the 2UZ to best suit towing and hauling needs. To achieve this, the biggest change with the 2UZFE is that the displacement was increased to 4.0L on the 1UZ to 4.7L, which greatly increased the torque.

The 2UZFE doesn’t have quite the cult following that the 1UZ or 3UZ does, and that’s partially because of the block which is made out of cast-iron rather than cast-aluminum, but also a weaker bottom end which we’ll talk about a bit later. With a cast-iron block, Toyota was able to save some cost during production and for trucks the weight savings of aluminum really aren’t worth it.

Other than the big change in displacement and the cylinder block material, the engine design is pretty similar to the 1UZ. Its a 90* V8, with aluminum heads, dual-overhead cams, 4 valves per cylinder, and it was in production from 1998 all the way until 2012, although in most places it died in 2009. Toyota began replacing it with the 1UR-FE and the 3UR-FE in 2010.

To increase displacement from 4.0L to 4.7L, Toyota increased the bore from 87.5mm to 94mm and the stroke from 82.5mm to 84mm.

  • 2UZ-FE: 94 mm × 84 mm
  • 1UZ-FE: 87.5 mm × 82.5 mm

Aside from bore and stroke, the 2UZ engine block is very similar to the 1UZ it’s based on in design and dimensions. It also has a 90 degree ‘V’ angle, 21 mm cylinder bank offset, and bore pitch of 105.5mm. An interesting change made in the bottom end is the reduction from 6 main bearing journals to 5.

Of all the changes that Toyota made to the 2UZ-FE throughout its production life, the addition of VVTi is the most important. With that change came a substantial increase in power and torque. With this system in place, the 2UZ-FE can change intake valve timing on the fly, allowing for valve overlap to be optimized for power and fuel consumption based on load, throttle amount, and RPM.

In the first few years of production, the 2UZ used a conventional throttle body, but as Toyota wanted to increase power and efficiency, they decided to shift to an electronically controlled throttle body system in late 2002. As far as fuel and spark goes, the 2UZ-FE uses a sequential multiport fuel injection system with eight four-hole fuel injectors, and a mass air flow sensor. It’s also equipped with Toyota’s Direct Ignition System (DIS) which uses individual ignition coils for all eight cylinders instead of a distributor.

Another interesting thing you’ll find on top of every 2UZ-FE engine is Toyota’s variable length intake manifold. With this system, the 2UZ can change the length of the intake runner which ultimately changes air velocity and tumble, which has a big impact on where the engine is most efficient at making power.

  • Production: 1998 – 2011
  • Cylinder Block Material: Cast-Iron
  • Cylinder Head Material: Aluminum
  • Valve Train: DOHC, 4 valves per cylinder
  • Stroke: 84mm
  • Bore: 94mm
  • Compression Ratio: 9.6:1
  • Displacement: 4664cc

Inside the VVTi version of the 2UZ-FE you’ll also find lighter pistons compared to the earlier engines and oil jets to help cool the pistons. Toyota also increased the compression ratio of the VVTi version to to 10:1 to further improve fuel efficiency.

The 2UZFE came in a variety of different Toyota products. Like I mentioned before, it was designed for Toyota pickups and SUVs. The 2UZ was equipped in the Lexus GX470 and the LX470. It was also equipped in the Toyota 4Runner, Land Cruiser, Sequoia, and Tundra.

  • Lexus GX470
  • Lexus LX470
  • Toyota 4Runner
  • Toyota Land Cruiser
  • Toyota Sequoia
  • Toyota Tundra

Just like the 1UZFE, the 2UZFE had minor modifications done to it over the years to increase its horsepower, torque, and fuel efficiency. The biggest change would be the addition of Toyota’s VVT-i system. To save some time I’ll put the power figures on the screen here.

  • 230 horsepower @ 4,800 rpm
  • 302 lb-ft @ 3,600 rpm
  • Minor revisions were added
  • 232 horsepower @ 4,800 rpm
  • 311 lb-ft @ 3,600 rpm
  • Toyota’s VVT-i system was added
  • 271 horsepower @ 4,800 rpm
  • 315 lb-ft @ 3,400 rpm
  • Minor revisions were added
  • 282 horsepower @ 4,800 rpm
  • 324 lb-ft @ 3,400 rpm

As you can tell from these numbers, the 2UZFE ended up with 52 more horsepower, and 22 lb-ft more than it started with. The largest jump occurred when Toyota added VVT-i, which added an impressive amount of power.

Just like the 1UZ, the Terminator Cobra supercharger, or Eaton M90 is a common addition the 2UZFE. With the addition of fuel injectors and an exhaust, the 2UZFE can make 380+ horsepower @ 6psi. Building the bottom end with lower compression ratio pistons, the 2UZFE can make 440+ horsepower @ 10psi. At one point Toyota’s TRD division offered a bolt-on roots-type supercharger kit for the 2UZ, which increased power output by 118hp, but unfortunately that kit is no longer in production. You can still find them used on eBay though if you’d rather have an OEM supercharger for your 2UZ.

There are two issues with shoving a ton of boost into the 2UZ: two bolt mains and weak connecting rods. This is an important distinction between the 2UZ that makes it significantly less popular for forced induction compared to the 1UZ or 3UZ. Two bolt main caps are much weak than four bolt main caps, but that doesn’t make it impossible to boost the 2UZ, you just have to be mindful of that weakness in the bottom end.

Also, the stock rods are pretty thin on most 2UZ variants and can often fail in stock form. If you’re throwing boost at your 2UZ, upgraded rods are generally a good idea for longevity.

A common, and interesting build is using the 2UZFE bottom end, and block, with all 1UZFE components. This allows you to turn your LS400 into an LS470. It’s not a super common build, for the simple fact that you could build your engine with a supercharger or turbo for the same amount and make more horsepower, but it’s still really cool.

So, overall the 2UZ is actually a lot like the 1UZFE. They are designed for different applications, but their parts are mostly interchangeable. The 2UZ is a super torquey, and super strong engine. It’s relatively small compared to its competitor’s engines, but it makes as much torque, or more, at a lower RPM than many other comparable truck engines of the time.

3UZ-FE

Last, but not least, let’s look at the 3UZ-FE. The biggest and most obvious change from the 1UZ to the 3UZ is the displacement, which was increased from 4.0L to 4.3L. Just like the 1UZ, the 3UZ-FE uses an cast-aluminum engine block with cast-aluminum heads.

To increase displacement from 4.0L to 4.3L, Toyota increased the bore from 87.5mm to 91mm, while leaving stroke the same at 82.5mm. This makes the 3UZ-FE quite oversquare and allows it to reach a really high peak RPM without stressing the internals excessively. If you want a better explanation on how bore and stroke work, check out our Bore vs Stroke video for more info.

  • 3UZ-FE: 91 mm × 82.5 mm
  • 1UZ-FE: 87.5 mm × 82.5 mm

The block had same 90 degrees angle, 21mm cylinder bank offset, and 105.5mm bore pitch as the 1UZ-FE. Interestingly enough, Toyota decreased the cast-iron cylinder liners by 0.5 mm, which ultimately helped reduce weight and improve cooling, but comes at the cost of being weaker. Of course, in stock form the reduced liner thickness isn’t an issue, but for high-performance applications this can sometimes be a problem.

Like the 1UZ, the 3UZ is equipped with a forged steel crankshaft, forged steel connecting rods, and lightweight aluminum pistons. This is a great example of Toyota doing what they’re known for with many of their engines, and that’s just simply overbuilding it. Really, the forged bottom end is overkill for the stock power output.

The 3UZ-FE cylinder heads are nearly identical to the cylinder heads found on the 1UZ-FE, and in-fact 1UZ-FE heads bolt right on to the 3UZ-FE block and will actually work completely fine with some minor modifications to the pistons.

Another interesting thing you’ll find on top of every 3UZ-FE engine is Toyota’s variable length intake manifold. With this system, the 3UZ can change the length of the intake runner which ultimately changes air velocity and tumbled, which has a big impact on where the engine is most efficient at making power. By changing the length of the intake runner based on RPM, the 3UZ is really good at making power across the entire rev range.

To recap on some of the basic info, we’re looking at a production run from 2000 to 2010 in road cars, an all aluminum construction, dual-overhead cams, 4-valves per cylinder, and a 10.5:1 compression ratio. With that out of the way, let’s look at the applications it was used in and some of the common problems.

  • Production: 2000 – 2010
  • Cylinder Block Material: Aluminum
  • Cylinder Head Material: Aluminum
  • Valve Train: DOHC, 4 valves per cylinder
  • Stroke: 82.5mm
  • Bore: 91mm
  • Compression Ratio: 10.5:1
  • Displacement: 4292cc

Just like the 1UZ, the 3UZFE was designed for luxury cars. It came in a number of different Toyota products, but they were all luxury oriented vehicles. The 3UZFE was equipped in the Lexus GS430, LS430, and SC430. It was also equipped in the Toyota Crown Majesty, and the Soarer.

  • Lexus GS 430
  • Lexus LS 430
  • Lexus SC 430
  • Toyota Crown Majesty
  • Toyota Soarer

Toyota also used this engine in their Supra GT500 Super GT car as well as their Lexus SC430 GT500 Super GT car. Those racing versions were obviously heavily modified for racing and featured increased displacement compared to the standard 3UZ.

Over the years the 3UZFE had minor upgrades done to it. These upgrades increased horsepower, torque, and fuel economy. With these upgrades there are three power ratings for the 3UZ depending on the year it was produced. The power increases are relatively minor and to save some time I’ll just put those power figures on the screen.

  • 282 horsepower @ 5,600 rpm
  • 307 lb-ft @ 3,500 rpm
  • 290 horsepower @ 5,600 rpm
  • 320 lb-ft @ 3,400 rpm
  • 304 horsepower @ 5,600 rpm
  • 325 lb-ft @ 3,400 rpm

As you can tell from these numbers, there were only slight gains in horsepower. Most of these gains were a result of computer re-calibration, and the physical parts were left unchanged.

Unfortunately, the 3UZ is a double edge sword. Its super awesome because its mostly the same at the 1UZ, which can make tons of power really easily. The reason that the 3UZ is limited by the stock block is the bore size. The cylinder block is identical to the 1UZ’s, but the larger bore of the 3UZ decreases the size of the cylinder sleeves.

As long as you’re not pushing your car past 600 horsepower, than the stock block will work just fine for you. Like I said though, it is limited by the stock cylinder sleeves, so you don’t have to be very careful when adding boost.

So as you might have figured out by now, the 1UZ and the 3UZ are basically the same. They share a large amount of their components, and make similar power. The difference worth mentioning is that the 3UZ is weaker than any other UZ engine.

As far as common problems goes, there really isn’t much to speak of. During my research for this video, the only issue I could really find that appears to be consistent is the timing belt, but that’s really a wear item and should be replaced at regular intervals regardless.

So, that’s pretty much all I have for you guys today. That’s the entire Toyota UZ engine family in a nutshell.

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