Since lawn dump cart tires are usually pneumatic and have thicker treads, you won’t be inflating them the same as you’d inflate your car tires. For the most part, your dump cart tires should be inflated to around 30 to 35 PSI. However, the actual recommended PSI depends on the manufacturer’s recommendations and the type of tires you have. Make sure you’re checking the inner rim of the tire to figure out the PSI ideal for your specific tires. Don’t just inflate the tires as much as possible. When pneumatic tires are overinflated, they tend to have less traction and make for a bumpy ride.