303 Hydraulic Oil Vs AW 32: Which Is Better To Choose

You should buy good hydraulic oil for your hydraulic equipment like tractors or equipment construction. But, do you need help to understand what is the difference between 303 Hydraulic oil vs. AW 32?

303 hydraulic oil is best for tractors for a warmer temperature of +32°F. Otherwise, AW 32 is good for cold weather applications such as the pump of a snowplow.

However, their differences don’t end here. So, we compare the aspects where the 303 hydraulic fluid and AW 32 perform best, and you can easily decide which is best for you.

Let’s get started! 

Table of Contents

Why Do You Use Hydraulic Oil?

Hydraulic oil is used in hydraulic equipment such as hydraulic tractors, Bulldozers, power steering systems, automated gearboxes, traction control, garbage trucks, industrial machines, elevators, or even fixing a ripping chainsaw.

Hydraulic oil helps pressurize the hydraulic equipment to perform many machining operations. It transmits energy throughout the system and allows the equipment to work and motion to complete. On the whole, heat transmission, lubrication, and contaminant control are all handled by hydraulic oil.

303 Hydraulic Oil Vs AW 32 Comparison Table: Quick Overview

303 Hydraulic Oil Vs AW 32

Take a glance at this quick comparison table so you can easily realize the basic differences between 303 hydraulic oil vs. AW 32.

Differences303 Hydraulic OilAW 32
Viscosity Index6198
SAE Grade20w10w
Flash Point400 degree Fahrenheit420 degree Fahrenheit
Pour Point206.6 degree Fahrenheit-38 degree Fahrenheit
Best Suitable ForEquipment with piston pumpsEquipment with gear and piston pumps
Suitable TemperatureWarmer temperatureCold temperature
CostCheaperBit expensive

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Brief Overview Of 303 Hydraulic Oil

303 Hydraulic Oil

303 hydraulic oil is a universal tractor hydraulic fluid. It’s a low-viscosity, single-grade lubricant. It can be considered as a transmission fluid that lubricates the moving parts within the transmission. On top, 303 Hydraulic fluid is blended from quality virgin base oils and adds high-performance additives.

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  • Provides extreme pressure to create enough energy
  • Protect the brake squawk areas
  • Anti-wear additives offer minimum metal-to-metal contact


  • Not suitable for all hydraulic system

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Brief Overview Of AW 32 Hydraulic Oil

AW 32 Hydraulic Oil

AW 32 hydraulic oil suits normal to moderate and long-term service requirements. It can be considered as a medium to transfer power.

It can be used in circulation, splash baths, and ringed oil systems supplying bearings and gears.


  • High-quality Hydraulic oil worth the cost
  • Doesn’t lose ability when fluid gets warm
  • Provide long service and high performance
  • Rust inhibitors deposit rust protective films on metal surfaces.


  • No cons

Here are product lists for the Best AW 32 Hydraulic Oil

BrandProduct NameViscosity GradeTypeAdditivesPrice
Brand AHydraLube AW 32AW 32Mineral-basedAnti-wear,$XX.XX
Brand BPowerHydro AW 32AW 32Synthetic-basedAnti-wear,$XX.XX
Brand CUltraGlide AW 32AW 32Semi-syntheticAnti-wear,$XX.XX
Brand DHydroGuard AW 32AW 32Bio-basedAnti-wear,$XX.XX
Brand EOptiLube AW 32AW 32Synthetic-blendAnti-wear,$XX.XX

303 Hydraulic Oil vs. AW 32

303 Hydraulic Oil vs. AW 32

Now that you know the basic differences between hydraulic fluids let’s discuss their key differences.

1. Purpose

Though both are hydraulic oil, they serve different purposes.

  • 303 Hydraulic Oil

303 hydraulic fluid applied for multi-purpose. It can be utilized as a hydraulic medium, power steering, power take-off, power brakes, and implement drive.

John Deere, cat equipment with piston pumps, and most farm tractors are good to go with this fluid as it is specially designed for tractors and similar equipment.

The differential, gearbox, and final drive gears in tractors and tools are lubricated by 303 Hydraulic oil.

  • AW 32

AW 32 oil is mostly used for common purposes like a vane, gear pumps, and pistons, particularly when pressures surpass 1000 psi. AW 32 fluid is also used to lubricate reciprocated compressors that are minimally loaded.

2. Viscosity Index

The viscosity or thickness of hydraulic oil is crucial in deciding how well your pedal will perform.

  • 303 Hydraulic Oil

303 hydraulic oil has a lower viscosity index compared to AW 32. It’s good for the smooth pedal response. Though its low viscosity index can easily be affected by temperature changes.

  • AW 32
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AW 32 hydraulic oil has a high viscosity index, allowing more mechanical response. It provides consistent operation throughout a wide variety of temperature and drain intervals. On top-notch, high viscosity means that it prevents the oil from breaking down or becoming thinner under high temperature and pressure.

3. Flash Point

Flashpoint is an essential factor for any hydraulic fluid. It’s the lowest temperature at which an oil will spontaneously combust.

  • 303 hydraulic oil

303 tractor fluids have a lower flash point than AW 32. So you might find it less stable than the AW 32.

  • AW 32

On the contrary, AW 32 hydraulic oil comes with a 420-degree Fahrenheit flash point. That indicates its higher flash point will help you to use your machinery and equipment safely.

4. Controlling Oxidation

Better oxidation control is very important to prevent corrosion and loss in foam control. Otherwise, oxidation reactions can be responsible for viscosity increase, varnish, deposit, and sludge formation. Good oxidation prevents damage to your equipment.

  • 303 Hydraulic  Oil

303 hydraulic oil also comes with quality oxidation stability that offers resistance against chemical changes due to the long storage of biodiesel. However, as the formulation of 303 fluid is quite old, its oxidation control could be better than AW 32.

  • AW 32

AW 32 provides excellent oxidation and heat stability, which reduces sludge and varnish. It causes a minimum oxidation reaction, so you get the proper amount of functional oil in the system. Also, it expands oil and equipment lifespan protecting vital components.

5. Anti-wear

Anti-wear hydraulic oil is a mineral-based oil with additives in the mixture that expand the lifespan of the oil and provide great thermal stability.

  • AW 32

AW 32 hydraulic oil is dedicatedly made for anti-wear purposes. Its premium anti-wear additives reduce metal-to-metal contact even at high pressure. Also, these superior additives increase lubricant performance and your equipment’s life.

  • 303 Hydraulic Oil

Though 303 hydraulic fluid has anti-wear properties, it’s not designed for anti-wear. Using this oil, you can get enough anti-wear protection to achieve smoother operation and a long life span for tractors.

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What is the difference between 303 Hydraulic Oil and AW 32?

The main difference between 303 Hydraulic Oil and AW 32 is their viscosity index and additives.

Which oil is better for high-pressure hydraulic systems?

AW 32 is better suited for high-pressure hydraulic systems.

Can I mix 303 Hydraulic Oil and AW 32?

It is not recommended to mix different types of hydraulic oils.

What is the viscosity rating of 303 Hydraulic Oil and AW 32?

303 Hydraulic Oil has a viscosity index of 46, while AW 32 has a viscosity index of 32.

Is 303 Hydraulic Oil biodegradable?

Yes, 303 Hydraulic Oil is biodegradable.

Which oil is more resistant to thermal breakdown?

AW 32 is generally more resistant to thermal breakdown.

Can I use 303 Hydraulic Oil or AW 32 in my car’s power steering system?

It depends on the manufacturer’s specifications, but AW 32 is often recommended for power steering systems.

Which oil is more suitable for use in cold weather?

AW 32 is more suitable for use in cold weather.

Can I use 303 Hydraulic Oil or AW 32 in my boat’s hydraulic system?

It depends on the manufacturer’s specifications, but both oils may be suitable for use in boat hydraulic systems.

What are the recommended storage and handling practices for 303 Hydraulic Oil and AW 32?

Both oils should be stored in a cool, dry place and handled according to standard safety practices.

What is AW 32 hydraulic oil used for?

AW 32 hydraulic oil is commonly used for industrial and mobile hydraulic systems, such as those found in heavy equipment, construction machinery, and machine tools.

What does 32 mean in hydraulic oil?

The number “32” in AW 32 hydraulic oil refers to its viscosity index, which indicates its resistance to flow.

What viscosity is AW 32 hydraulic oil?

The viscosity of AW 32 hydraulic oil is approximately 32 centistokes (cSt) at 40°C, making it a medium-thin oil.

Final Thoughts

At present, 303 Hydraulic fluid is rarely used. Some farm tractors might use it. Other than tractors, they can be used in construction, forestry, irrigation, and mining equipment applications. However, if you live in a hot area, then 303 hydraulic oil can be suitable for you.

Otherwise, we recommend using AW 32 hydraulic oil if you live in an extremely cold environment. It is made from purified paraffinic base oils and offers exceptional wear resistance, corrosion resistance, and oxidation, as well as foam and aeration control. So you can use this AW 32 for your hydraulic equipment and machinery, and it’s best recommended for most forestry equipment.

Finally, before you pick any hydraulic oil, check out if there’s any manufacturer’s recommendation for the type of oil needed in that machine.