Toyota has been around for decades now, and we can say that they dominated the car industry because of the way they are doing it, and they do it consistently.
They revolutionized the game, and there are stories that some companies bought their LS400 Luxury Sedan to break it down and analyze its material processes. Today, we will dig into Toyota’s 2008 AR engines that Camrys have carried, Venzas, Highlanders, and Lexus.
What are AR engines?
In 2008, Toyota introduced its first-generation AR engine for RAV4. Its primary market was mainly for consumers in the North America region, at first, and remained locally produced.
Later that same year, the 1AR-FE, a 2.7-liter engine option introduced for 4-cylinder Venza and Highlander models. Since its arrival, AR engines appear in E-class cars (Camry), Scion tC models, along with the models mentioned above.
AR engine family is an Inline-4 (I4) piston engine series manufactured by Toyota. It is an all-aluminum cylinder block with thin cast-iron liners, double overhead camshaft, almost identical to its predecessor, the AZ, but with variable valve timing on both intake and exhaust cams or popularly called as dual VVT-i.
This engine is equipped with low-friction technology: offset crankshaft – where the axis has been shifted by 10mm relative to the axis lines of the cylinder, 3-stage variable oil pump, roller rockers for the valve train, reduced tension in the piston ring, and auxiliary belt drive.
A Tumble Control System (TCS) is also added to reduce an unburned mixture and 12-hole high atomizing fuel injectors to reduce the fuel rate coming into the intake ports – these maximize fuel economy through efficient combustion in the chamber.
AR Engine Variants
There are six variants under AR engines, namely:
1AR-FE,2AR-FE, 2AR-FXE, 2AR-FSE, 5AR-FE, 6AR-FSE, and 8AR-FTS. All of these engines share the same fuel system and are gasoline powered.
1AR-FE and 2AR-FE are the basics. However, 2AR-FXE and 2AR-FSE are equipped with D4-S direct injection, and port injection is considered sub-variants of 2AR-FE as engine layouts.
Both are distinctively unique through different applications; and are more suitable for hybrid vehicles FF (Front Engine, Front-Wheel-drive) and FR (Front Engine, Rear-Wheel-Drive), respectively.
Going back to 1AR-FE, it is the 2.7- Liter version of the AR series. It was used in Venza, Highlander, Sienna, and Lexus RX. 2AR-FE is the 2.5 Liter version and was the engine used on the initial release of RAV4 in the US and Canada and Camry, Scion tC, Alphard, and Lexus ES250.
Moving through the list is the 5AR-F, which is similar to 2AR-FE was released in China in 2013. Same components and all but different production market.
Next is the 6AR-FSE or FBS for some, is a twin-cam, 2.0-L engine with a high geometric compression ratio of -12.7. It can work both on Otto and modified-Atkinson cycle in parallel to its output power.
Unlike 1ARs and 2ARs, exhaust gases are recirculated uniformly due to an added manifold even though there are no additional intake geometry actuators. 6AR-FSE appears in Camry (Russia, China, Thailand, Cambodia, Kazakhstan, and Myanmar) and Lexus ES 200.
And last but not least is the 8AR-FST, a 2.0 L turbocharged direct-injected engine. In Lexus NX200t, Debuted was Toyota’s first gasoline turbo after the termination of 3S-GTE and 1Jz-GTE.
Just like 6AR-FSE, it can operate in both Otto and modified-Atkinson cycle with power peaking at 235HP. Equipped in this engine is ESTEC D-4ST, which are separate twin injectors so your engine could perform high-pressure direct injection or direct cylinder injection at varying engine speeds.
Here’s a tabulated presentation with their respective displacement, bore and stroke, torque, power, and compression ratio:
| Engine | Displacement, cm3 | Bore x Stroke, mm | Compression Ratio | Output, HP | Torque, lb-ft |
| 1AR-FE | 2672 | 90.0 x 105.0 | 10.0 | 185 @ 5800 | 186 |
| 2AR-FE | 2494 | 90.0 x 98.0 | 10.4 | 179 @ 6000 | 173 |
| 2AR-FXE | 2494 | 90.0 x 98.0 | 12.5 | 160 @ 5700 | 153 |
| 2AR-FSE | 2494 | 90.0 x 98.0 | 13.0 | 178 @ 6000 | 163 |
| 5AR-FE | 2494 | 90.0 x 98.0 | 10.4 | 179 @ 6000 | 173 |
| 6AR-FSE | 1998 | 86.80 x 86.80 | 12.7 | 165 @ 6500 | 147 |
| 8AR-FTS | 1998 | 86.80 x 86.80 | 10.0 | 238 @ 4800 | 258 |
Defects and Complaints
No matter how simple or intricate the engine is, one way or another, some problems may occur along the way at any given time, regardless of your preventive measures to counter those.
The list of defects, which is minuscule, is recognized in 1AR/2AR engines that it has a brief engine knock or rattle coming from a cold start-up. Also, oil leakage from the front crankshaft oil seal is also reported, which can be found on Camry models (ASV50, ASV51).
Apart from that, AR engines are reliable and simple, which is the key to a reliable machine.
What makes it special?
As you already know, AR engines replaced AZ engines. But several things make AR engines differ from their peers. One is the offset crankshaft (1AR-FE,2AR-FE); the primary reason is to lower the friction between the piston and the cylinder walls, resulting in 11% better fuel economy.
In 6AR-FSE, an additional camshaft is installed, which drives a high-pressure fuel pump. A water EGR cooler and cooled EGR control were also added.
8AR-FTS is a turbocharger and designed to withstand increased loads. Strengthened cylinder blocks, additional labyrinth-type oil separators, and a conventional valve PCV are installed in the cover.
Another separator chamber is established in the crankcase for the boost mode, so crankcase gases are discharged through the ejector to intake. Three thermostats are installed: traditional, the thermostat on the cylinder block, and the manifold thermostat.
This thermostat gives us information to control the coolant flow through the block and to avoid excessive heating of the intake air.
Summary
Car producers and consumers share the same vision for future automobiles; to be more fuel-efficient and innovative. Humans, after all, are progressive beings. So, to wrap this all up, AR engines are reliable and continues to do so.
With its new technology features such as low-friction technology, additional cams, improved cooling, and ventilation system, we can say that these engines will meet your demands in terms of fuel economy, longevity, and satisfaction.