Toyota has replaced the 1.4-liter VVT-i engine (4ZZ-FE) in their Auris with a new, smaller, and more efficient Dual VVT – I drivetrain. This means that it produces power just as effectively yet is less fuel-thirsty than before while also weighing down its four-wheeled siblings.
Not only that, but the Toyota 1NR is also 36% lighter due to thinner pistons. Among other improvements made by Toyota engineers, overtime for this reworked motor design has affected the development and overall success of the engine.
There are four iterations or variants of the Toyota 1NR engine – 1NR-FE, 1NR-FKE, 1NR-VE, and 1NR-FBE.
What are Toyota 1NR Engines?
The Daihatsu department was given priority in developing and manufacturing new small-displacement series, but NR engines are best recognized as Toyota model engines.
The first engine of the series, the 1NR-FE, was released in 2008 for the European market. It instantly replaced the obsolete 4ZZ-FE and then progressively superseded the 2NZ-FE and 2SZ-FE in the Japanese market.
The Toyota 1NR engine is a member of the NR family of engines.
The NR series has aluminum engine blocks and DOHC cylinder heads. It also employs multi-point or direct fuel injection and has four valves per cylinder. Dual VVT-i is standard on the 1NR, 2NR, 3NR, 4NR, 5NR, 6NR, and 7NR engines, while VVT-i is standard on the 8NR engine, allowing it to function in both the Otto and modified-Atkinson cycles to increase thermal efficiency.
Engine Specifications and Design:
- Production Run: 2008 – Present
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Aluminum
- Configuration: Inline 4
- Bore: 72.5 mm
- Stroke: 80.5 mm
- Valvetrain: DOHC four valves per cylinder
- Displacement: 1.3 L (1329 cc)
- Compression Ratio: 11.5 and 13.5 (1NR-FKE)
- Weight: 196 lbs.
- Maximum HP: 99 HP at 6,000 RPM
- Maximum Torque: 97 lb-ft at 3,800 RPM
The 1NR-FE is a four-cylinder inline engine with dual VVT-i and Stop & Start technology. The Yaris XP9F was brought onto the European market in late 2008, with the primary goal of improving engine performance while lowering pollutants and fuel consumption.
The cylinder block is designed for lightweight but high compression engines. The aluminum “open deck” with thin cast-iron liners act as one durable piece, providing strength and power that will last until the next engine rebuild.
The wall thickness between each of these cylinders measure just 7 mm, so there’s no need to worry about reboring your motor if something goes wrong – you’ll be a good go right away.
The crankshaft’s axis has been displaced by 8 mm relative to the cylinder axis lines, lowering the lateral component of the piston’s force imparted on the cylinder wall and reducing wear. There are four balancing weights on the crankshaft, shortened journals, and separate main bearing covers.
The high-rise spacer is an excellent innovation that allows for more intensive coolant circulation near the top of a cylinder, which improves heat dissipation and helps to even thermally load.
The camshafts are housed in a separate housing placed on the cylinder head, which simplifies the cylinder head’s design and manufacturing process.
The valvetrain mechanism includes hydraulic lash adjusters and roller rockers. Old-style adjustable tappets are used in Asian markets.
Throughout the engine, advanced engineering has been used. Toyota engineers simplified the intake channel inside the engine, employed computer simulation to improve airflow, smoothed all surfaces to reduce turbulence, and rounded out all curves and rough edges.
The piston design is one of the most important aspects of the 1NR-FE engine. They are built with a reduced contact surface and employ carbon ceramide, a sophisticated material used in Formula One engineering, to minimize friction. They are smaller and lighter than the previous 1.3 L unit. To decrease pumping losses and NOx emissions, the engine has cooled exhaust gas recirculation.
Pistons are made of aluminum alloy with a cut skirt and a tiny T-shaped protrusion. The top compression ring groove is anodized, and the upper compression ring’s edge and oil scraper have an anti-wear PVD coating.
The piston pins are not fully floating and are press-fitted into the connecting rod, which is a significant disadvantage. Please note that Toyota officially restricts the reuse of pistons, connecting rods, and piston pins for 1NR and 2NR engines that have been dismantled.
Applications of Toyota 1NR-FE Engine:
- Subaru Trezia
- Perodua Myvi/Daihatsu Sirion
- Toyota Corolla
- Toyota Auris
- Toyota Colla Axio
- Toyota iQ
- Toyota Etios
- Toyota Passo
- Toyota Ractis
- Toyota Probox
- Toyota Urban Cruiser
- Toyota Vios (XP150)
- Toyota Verso-S
- Toyota Yaris (XP150)
The 1NR-VE is one of the most popular engines in Southeast Asia. It’s been used as a basis for producing Daihatsu and Perodua vehicles, with more being made every year. The engine is known for being very reliable and producing great torque.
The manual model has ECE fuel consumption statistics of 61 mpg, and the automatic variant has fuel consumption figures of 59 mpg. The engine has a power output of 93 hp and a torque output of 189 lb-ft.
Because of the new Eco Idle stop-start technology and regenerative braking, the Perodua Bezza Advance version and all variations of the new third-generation Myvi are capable of 62 mpg, which is better than the previous generation engines.
Applications of Toyota 1NR-VE Engines:
- 2015 – 2021 Toyota Avanza/Daihatsu Xenia
- 2021 – Present Toyota Avanza/Daihatsu Xenia (W100)
- Perodua Bezza
- Perodua Myvi/Daihatsu Sirion (M800)
The new 1NR-FKE is a variant of the 1NR-FE, introduced in early 2014. Toyota claims this engine will have 38% thermal efficiency. It employs an Atkinson cycle like hybrid engines. Still, it produces less torque with higher maximum outputs at no reduction on power production due to its different design principles that allow for more efficient operation under certain conditions, even at high-speed conditions.
Variable Valve Timing-intelligent Electric VVT-iE operates valves. The intake port has a novel form that provides a powerful vertical tumble flow. Combustion is enhanced, and loss is decreased. Toyota estimates that with idling halt and other operations, it will contribute to fuel efficiency benefits of around 15 percent.
Applications of 1NR-FKE Engines:
- 2014 – Present Toyota Vitz
- 2014 – Present Subaru Trezia
This is a new engine for the Brazilian market. The flex-fuel, 1.3 liter VVT-i will be available only on Toyota’s Etios and Yaris hatchbacks made in Brazil, which can run a gasoline or E85 fuel.
Problems Surrounding Toyota 1NR Engines:
The difficulties raised towards the 1NR engines will be addressed throughout the remainder of this text. We name them the most prevalent issues for a reason.
These are a handful of the most common issues where Toyota 1NR engine troubles arise. The engine provides an excellent blend of dependability and efficiency. However, no engine is flawless, and there are no exceptions here.
1. Excessive Oil Consumption
The most well-known and widespread issue with the 1NR-FE is high oil consumption, which frequently emerges at mileages much below 60,000 miles. Toyota’s standard explanation is that the piston rings became jammed. The requirement to replace pistons and connecting rods concurrently does not allow for a low-cost engine renewal, although cylinder block reboring is not required.
Oil consumption is a problem that was recognized in TSB EG-0095T-1112. Production changes were implemented in early 2013, which included modified rings and pistons with connecting rods and valve cover replacement for those with oily valves or nozzles.
2. Excessive Soot Deposits
Excess soot deposits in the combustion chamber, on valves, and valve seats can decrease compression. This causes an extended period of engine start, which also generates DTC P1604. TSB EG-00037T-TME recognizes the defect as an excessive deposit of this type that may cause a reduction or loss of power.
The following passage details an issue with some cars where it’s been observed they experience taking longer than normal due not just because there was more time needed for ignition but also from build up within certain components such as pistons being coated by residue.
3. Rattling or Knocking Noise During Operation
Again, large deposits in the combustion chamber cause a rattling or banging noise during engine operation. The problem is acknowledged and explained in TSB EG-0094T-0714, which describes some production adjustments introduced at the beginning of 2014.
The recommendations are nearly identical to the EG-0095T-1112. However, it is advised that the pistons be replaced with the next, even more, customized variant, and the engine ECU firmware be reprogrammed.
4. Clattering noise from the Timing Chain area
A ticking or clattering noise from the timing chain region, commonly apparent after a cold start and until the engine warms up. Recognized as a “feature” and detailed in TSB EG-00039T-TME. You have two options, either do nothing or replace the timing chain and install a redesigned tensioner arm.
The Toyota 1NR engine is a reliable and fun-to-drive engine. Smaller but more efficient Dual VVTi drivetrain, the 1NR produces power just as effectively but consumes less than before. Add in excellent fuel economy, and you’ve got one of the best engines out there today.
If you’re looking for an economical vehicle that doesn’t compromise performance or reliability, this might be your best option. It does not have major issues, and with proper maintenance, this engine is a steal.