AW32 vs AW46 Hydraulic Oil: What’s the Difference, and Which Should You Use in Your Loader?
If you own or operate a compact loader or mini-excavator, you already know hydraulic oil is the lifeblood of the machine. It’s what powers the lift arms, bucket movement, steering, and any hydraulic attachment you plug in. But one of the most common questions we hear at NESHER Equipment is: Should I use AW32 or AW46 hydraulic oil — and when? Let’s break it down in simple terms so you can make the right choice for your machine and climate.
What AW32 and AW46 Actually Mean
The “AW” stands for Anti-Wear, meaning the fluid contains additives designed to protect pumps and hydraulic components under pressure. The numbers — 32 and 46 — refer to viscosity, or thickness.
AW32 = thinner oil Example: https://amzn.to/4qq7j3E
AW46 = thicker oil. Example: https://amzn.to/3N3dw7b
Just like motor oil, hydraulic oil thickness affects how it flows. A lighter oil moves more easily in cold conditions, while a thicker one maintains better protection in higher heat and heavy-load work.
When to Use AW32
AW32 is generally recommended for:
Cold climates or winter use
Short, quick hydraulic cycles
Equipment that must start easily in low temperatures
Because it flows more freely at low temperature, AW32 helps prevent sluggish hydraulics on cold mornings. If you’re operating your loader in winter, unheated barns, or northern regions, AW32 can make a noticeable difference in performance.
When to Use AW46
AW46 shines when:
Ambient temperatures are warm
The machine is used for heavy lifting
Hydraulics are under continuous load
You want extra film strength for protection
In summer heat, thicker AW46 maintains better lubrication and resists thinning as the oil heats during use. It’s ideal for long workdays, hot climates, and high-duty cycles like moving dirt, rock, or palletized material.
If temperatures swing drastically where you work, switching twice a year can keep your machine performing smoothly. A good rule of thumb:
Below 20°F (-6°C): AW32 performs better
Above around 50°F (10°C): AW46 is ideal
In between those temperatures, you could get away with either oil. Mild zones can often run AW46 year-round, but cold regions will benefit from switching to AW32 during winter.
Can You Mix AW32 and AW46?
Theoretically yes, moderate amounts can blend safely, and you basically end up with a number somewhere between 32 and 46. Practically speaking, this happens a little bit everytime you change your oil since you always some left in your hydraulic rams and hoses. But it’s better to run as much of one grade at a time as you can for consistent viscosity so you know what you have in your machine. When switching seasons, a partial drain and refill is usually acceptable — but a full change is optimal if you’re seeking peak performance.
If you don’t go into extremes though, and just have generally cold winters, topping up with AW32 in the winter can be helpful. For extremely cold winters, draining and replacing what is in your hydraulic tank with AW32 is better. When spring and summer roll around, don’t forget to switch back to AW46, though, as the thinner winter AW32 oil won’t protect your seals and other hydraulic components as well when ambient temperatures are warmer.
Final Thoughts
Choosing the right hydraulic oil is an easy way to improve efficiency, protect your pump, and extend machine life. AW32 keeps your loader responsive in winter, while AW46 delivers strength and heat stability in summer. Paying attention to seasonal temperature can make your electric loader run smoother, lift stronger, and last longer.
If you have questions about what’s best for your climate or one of your NESHER machines, we’re always happy to chat. Reach out to us today!