I'm looking for EP2 lithium based grease for heavy duty bearings. I don't know the difference between Q8 Rembrandt EP 2 and Mobil Unirex EP2. Can you let me know what the key differences are?

Both Q8 Rembrandt EP 2 and Mobil Unirex EP 2 are lithium-based EP2 greases, meaning they have a similar consistency (NLGI 2) and contain extreme pressure additives.

However, the key differences are:

1. Packaging / application

Q8 Rembrandt EP 2 is often supplied in Lubeshuttle cartridges (closed system, cleaner application)
Mobil Unirex EP2 is typically supplied in standard grease cartridges
2. Thickener & formulation

Q8 Rembrandt EP 2: standard lithium grease (mineral oil based)
Mobil Unirex EP2: typically lithium complex grease, which is a higher-performance variant with better thermal stability and longer life
3. Additive package / performance level

Both contain EP additives, but:Mobil Unirex EP2 generally has a more advanced additive package, aimed at longer service intervals and higher temperature resistance
Q8 Rembrandt EP 2 is more of a robust multipurpose grease for general heavy-duty use
4. Application focus

Q8 Rembrandt EP 2: versatile, cost-effective, suitable for general industrial and off-road equipment
Mobil Unirex EP2: typically positioned slightly higher, often used where higher performance, longer life or higher temperatures are required
 
In short:

Same category (EP2 lithium grease)
Different packaging, additive technology and performance level