A portable fuel container is less likely to spill fuel when filling equipment if...  it is not overfull when you begin filling.  you fill it on a cement pad  you fill it on the ground

A portable fuel container is less likely to spill fuel when filling equipment if:

1. It is not overfull when you begin filling: Starting with a container that is not overfull reduces the risk of spillage. This is because when a container is overfull, the fuel has less space to move around, making it more likely to spill out when you start filling equipment.

2. You fill it on a cement pad: Filling a fuel container on a cement pad can help prevent spills. This is because cement pads are typically flat and stable, reducing the risk of the container tipping over. Additionally, any spills that do occur will be easier to clean up on a cement pad compared to other surfaces.

3. You fill it on the ground: Filling a fuel container on the ground can also help prevent spills. This is because the ground provides a stable surface for the container. However, it's important to ensure that the ground is flat and free of any potential hazards that could cause the container to tip over.