Record sustained and short peak grades in percent, not a visual guess. Note cross-slopes separately.
The steepest number is not the whole route.
A published maximum grade may describe a controlled surface. Your decision also depends on cross-slope travel, wet traction, edge risk, turning space and whether recovery can be done safely.
Clay, loose soil, exposed roots, wet grass and ruts can change traction even when the headline grade fits.
Identify safe pickup access and places where a loss of traction could reach water, a road, steps or a retaining edge.
Disqualifying checks
- Published grade is below a measured route the mower must traverse.
- The maker does not document edge behavior for the property’s hazard.
- Soft-ground or cross-slope ability is unknown and no returnable trial is available.
- Routine recovery would put a person on an unsafe slope.
Published slope limits are manufacturer claims until tested in the complete property context.