Dual VVT-I Engine: More Horsepower and Fuel Economy

An engine is like a machine that makes a vehicle run as per its performance. It changes energy from the fuel into mechanical energy and responds to motion in the process. 

VVT-I Engine: Variable valve Timings; this engine system changes the time of intake valves by connecting a special system between the camshaft drive(belt) and the intake camshaft.

Dual VVT-I Engine: This system adjusts timings equally on intake and exhaust.  Dual VVT-I system was revealed in 1998 on the RS 200 Altezza;s 3S-GE engine. It is present in Toyota 3.5 liter 2GR -FE V6 Engine. The system improves the engine’s performance by controlling intake and exhaust airflow and pipe emissions in any condition.

What is a dual VVT-i engine?

The latest technology introduced in 1998 was dual VVT-I (Variable Valve Timing with Intelligence ). You can see the system on the cylinder head working as an automatic time controller of the engine’s intake and exhaust. 

The system works by adjusting the timings of valves. Toyota says that by optimizing valve timing based on driving conditions, VVT-i increases power, improves fuel economy, and reduces emissions.

According to Toyota, optimizing valve timings that rely on the driving conditions system helps to improve energy levels, fuel economy, and low emissions. The system has made the engine more efficient and eco-friendly.

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Is it a dual VVT-i engine 4-cylinder?

The dual VVT-I engine is 4 -cylinder; vehicles with dual VVT-I systems are HondaF20C/F22C, 240 bhp from a 2 liter naturally aspirated engine. 

The awesome 4-cylinder engine powered the Honda S 2000 in performance. Alfa  Romeo Twin Spark, having 4 cylinders. 

It uses a second smaller spark plug at the end of the combustion chamber for each cylinder to improve combustion efficiency.

Is a dual VVT-i engine a V6?

The V6 engine consists of a six cylinder piston engine; here, cylinders share a common crankshaft.

Crank Shaft  

It is a mechanical part used in a piston engine that changes the reciprocating motion into rotational motion.

V6  are of short lengths. V6 engines are the larger engine option for vehicles that are otherwise produced with inline-four engines.

It was first introduced in 1998 on the RS200 Altezza’s 3S-GE engine. Dual VVT-i is in Toyota’s 3.5-liter 2GR-FE V6 engine on the 2005 Avalon. This engine can be found on numerous Toyota and Lexus models.

How does the Dual VVT-I engine work?

This helps to bring movement in camshaft persistence automatically. The system changes the camshaft lifts, which tells about how long these valves remain open or closed.

Theme is to change power or energy to move the valves within adjusted time. The program is already installed in the car that knows the running capacity or speed of the engine/car. 

The movement is complex and mechanical, easy for a professional mechanic to understand.

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How does the camshaft move?

Automatically, the power source means oil/ fuel makes the camshaft move due to oil pressure, the oil in the oil pump, and holes in the cylinders’ headcover. Holes are connected with small pipes to the oil pump; in this way, oil moves. 

There are four sensors with head cover cylinders, one sensor measures the intake, and the second sensor controls the exhaust VVT-I system The other two sensors at the other end of the cylinder head cover control what the camshaft possesses.

At the inside intake area, BBT evolves, moves this inside the piston, and oil moves to the holes of that area. The same goes for the exhaust area.

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Dual VVT-I engine advantages

A dual VVT_I system has been introduced to improve the car’s speed and engine performance. This engine is installed in the updated Toyota Corolla and other vehicles.

Professional mechanics prefer dual VVT-I rather than VVT-I systems in their customer’s cars. 

According to research and experts, this system brings flexibility to the engine. 

As this system controls intake and exhaust valves with a complex automatic system. The engine becomes more flexible. The car’s movement, speed, and braking system all go smoothly and with adjusted timings.

2-The system gives more power and energy to the engine.

The system is so updated and professionally mechanized that the source of energy and power makes the valve movements in control within the adjusted timings. 

With the pressure of oil, the movement takes place from the oil pump, the oil moves to the holes. The whole process makes the engine power, and the output is in the form of the best running of the car.

It raises the life of the engine. 

The system is updated and automatically mechanized, giving strength to the engine. A better intake and exhaust system makes the engine’s life long. 

The smooth flow of oil. The valves’ opening and closing system and their adjusted timings make the engine reliable.

The engine will run at a better speed.

Due to its automatic timing adjustment of the valves, more power is generated, fuel efficiency increases, and in return, it reduces emissions. 

It gives better torque at low speeds without causing knocking risks for the engine.

Due to the dual VVT-I system, cars/engines consume less gasoline or fuel.

The system boosts the response levels across the whole revs by varying the air-fuel intake and exhaust valve timing within the required time. 

To improve torque at a low and moderate speed of the engine, the system enhances fuel efficiency. Less consumption of fuel takes place at the end.

Does vvt increase horsepower?

The VVT_I system allows the engine to achieve its goals. Updated VVT systems are a combination of electronic and technological throttle control, and direct fuel movement that has been injected directly gives a smaller engine to generate awesome Horsepower.

VVT saves the horsepower from dropping off quickly after the horsepower peak. With this system, you will notice 5-10 percent better performance in output at the ends of torques and power curves.

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2013 Toyota Camry Dual VVT-I engine

Toyota 2013 Dual VVT-I engines include a 2.5-liter four-cylinder gasoline engine 3.5 liter V6.

2.5 liter four gives 178 horsepower and 170lb-ft of peak torque. The 2.5-liter engine has a dual VVT-I system that controls valve timings on the intake and exhaust camshaft. 

This control gives the best performance of the engine, its efficiency of engine speed. 

The DOHC 3.5 liter V6 comes in SE and XLE that generates 268 horses power at 6200 rpm and 248lb-ft of peak torque at 4700 rpm. 

In 2012 the engine redesigned for better output of 21 MPG city/31MPG highway fuel rates. 

The Camry SE  offers “D range” sequential shifting that gives manual shifting with the updated steering wheel paddle shifters. 

The console shifter is present in the updated  “D” mode.  To enhance the technology in the Camry SE, the automatic transmission features faster shift times when in “S” mode and downshifting blipping control to emphasize a sense of sportiness.

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Are Toyota dual VVT-i engines good?

Dual VVT-I engines are awesome in output as the system automatically adjusts the intake and exhaust valves and their timings. This process brings efficiency in running of cars and less fuel, oil or gasoline consumption. 

Dual VVT-I in 9+ models, the engine is flexible, long life of the engine is smooth in working, and gives mileage of 200000 miles (320000km).

It reduces emissions, gives the engine power, and gives better mileage and response.

What is the common cause of damage in a VVTI engine like Toyota?

The main and common cause of the dual VVT-i engine is the avoidance of the sensor system that makes it different from others. 

You will damage the system if you do not take care of the engine and car maintenance. 

Using low-grade and heavy-weight oil to save money will destroy your engine and system. In return, you will pay a high amount to repair or replace it.

The most common cause of damage in a VVT engine is using the wrong weight and grade of motor oil.

When the VVT-I solenoid does not function normally, it will affect the whole system. even it will affect the intake and exhaust opening and closing timings badly.

Why do people think the VVTI engine is more economical than the EFI?

People take this system as a time-saving comfort and money-saving comfort for them. Economically this engine gives a 30 percent fuel-saving benefit compared to other cars or engines. 

If you maintain your car and engine accurately, it will help you to reduce your fuel consumption. 

People believe that users who drive cars carefully having dual VVT-I engines use less fuel Careless drivers won’t be able to take advantage of less consumption of oil. 

This system improves combustion, takes better engine output with low emission, and reduces fuel consumption.

What is the difference between a valvematic and a dual VVTI Toyota engine?

Valvematichas is a mechanical system connected to the intake camshaft that allows altering of valve timings and lift .Here intake valves act as the throttle plates.

The main difference is that the VVT-I system works by changing valve duration for better response and performance, and Valvematic lifts the valves and controls the fuel.

How many miles could a Toyota VVT-i 2.4L engine run safely before you face a gasket issue?

Toyota VVT-I 2.4 L engine can run safely between 250,000miles and 300,000miles. This shows that the car’s engine can cover more distance and give better mileage with better maintenance techniques and good-quality fuel.

To avoid gasket issues overheating the engine, your engine cooling system must be in better condition.

Make sure the system has no leaking problem and an efficient radiator. Electric fans must be working correctly. Your car must definitely run for 16 to 20 years before facing a gasket problem.

05 Dual VVT-i engine problems

To solve the problems, you just need to know the problem 

As the system is too complex and mechanized automatically it is not so easy to find out the problem .Here are a few symptoms given that will help to know.

Head Gasket problem:  

Symptoms are: 

  • White color smoke will appear from exhaust 
  • Your engine will lose coolant 
  • White smoke from exhaust
  • When the engine misfires 

Water pump 

Symptoms are: 

  • Coolant will leak 
  • Overheating of engine 
  • Smoke from engine 

Ignition Coil 

Symptoms are: 

  • Problem to start the engine 
  • Misfiring of engine 
  • Bad fuel economy 
  • Check engine light 

Radiator fan not working 

Symptoms are: 

  • Fuse is burnt, or bad 
  • Dead wires of fan 
  • Sensor out of order 
  • Fan clutch breaks 

Oil pump: 

Symptoms are: 

  • Low oil pressure,  a light will be on your dashboard 
  • Temperature of the engine will increase 
  • Engine will produce a knocking sound.

Dual vvt-i engine size 

Engine Specifications 
Horsepower99 hp (98 bhp)
Rev. at Max Power6,000 rpm
Torque128 Nm
Rev. at Max Torque3,800 rpm
Dual VVT-I Engine Specifications
Engine Configuration 
Displacement1,329 cc / 1.3 l
Cylinders4 Cyl. / 4 V per Cyl.
Bore72.5 mm
Stroke80.5 mm
Compression Ratio11.5 :1
Dual VVT-I Engine Configuration

What is the best oil for VVT-i engines?


99 hp (98 bhp)

Rev. at Max Power

6,000 rpm


128 Nm


94 lb-ft

Rev. at Max Torque

3,800 rpm

Engine Configuration


1,329 cc / 1.3 l


4 Cyl. / 4 V per Cyl.


72.5 mm


80.5 mm

Compression Ratio

11.5 :1

What is the best oil for VVT-i engines?

5W-30 Oil

It is a fully synthetic motor oil specially designed for high-performance vehicles and engines. It is excellent for oil pumps, as it will clean the engine, as its low temperature will give long life to the engine. It will give you safe running of 20,000 miles.

 Caltex Havoline 10w30

Study shows that this oil performance is better than others. It is best for new cars. It can manage extreme hot temperatures and improve your engine’s performance in severe temperatures. This oil has a viscosity grade of 10 in low temperatures.

Liqui Moli 4-40 

Best quality high-performance engine oil. It guarantees engine performance and protection, awesome lubricant qualities, the best engine cleaning skills, excellent friction, and minimum wear . Its formulation has a tremendous effect on sealing materials. suitable for vehicles that have mileage of over 60000 miles. 

What is the difference between VVT-i and dual VVT-i?

VVT-I stands for Variable Valve Timing with Intelligence. The regular VVT-i system changes the intake valve opening duration in the combustion chamber. This will better improve  efficiency by

  1. Shortening the valve duration on lower RPMs or when the engine needs less power, and
  2. Increasing the valve time to let more fuel in as per the requirement of power.

Dual VVTi stands for Dual Variable Valve Timing Intelligence. The system takes care of both intake valves, and exhaust valves are also controlled electronically. The dual VVT-i has variable timing on both the inlet and exhaust cams


Article is about engines, especially about VVT-I and Dual VVT-I engine’s performances and working of engines. However, the system is complex and automatically controlled . Still, a few symptoms are mentioned for your help to recognize the real problem. 

Sometimes we start solving the wrong solution to unknown problems and get systems or engines more unsolved and complicated. Even though sometimes it is not possible to repair, just replacing is the option left for us. 

The best engine oil enhances the engine’s performance and lifespan. Never select low-quality oil for your vehicles to save money, as it will destroy the whole system and engine. Your car will stop running or moving.

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