Can you use 10 40 oil in a Toro lawnmower?

Using 10W-40 oil in a Toro lawnmower is generally not recommended, as most lawnmowers are designed to operate with 30-weight or 10W-30 oil. The viscosity of 10W-40 may not provide optimal lubrication for the engine, especially in warmer temperatures. Always refer to the owner's manual for the specific oil recommendations for your mower model to ensure proper performance and longevity.