While it certainly might seem like it would be dangerous or have negative consequences of some kind, running your lawn mower at full throttle actually has multiple benefits. The fact is, all lawn equipment is designed to run at full throttle for optimum results and best performance. You can slow down your cutting speed if necessary by using a lower gear on a riding lawn mower or walking slower with a push mower, but leave the engine running at full throttle.
As far as ground speed goes, if you’re talking about a riding lawn mower, the recommended speed is around 4 miles per hour. If you mow too fast, you will have a tendency to tear the grass, which will cause it to turn brown. The throttle on a riding lawn mower regulates the fuel-air mixture — it does not determine how fast the mower drives, but instead determines the engine speed (revolutions per minute, or rpms). You should run your mower at full throttle as much as possible, and here’s why.
It reduces engine stress
By running your riding lawn mower at less than full throttle, it actually puts more stress on the engine and other parts. For example, the battery life can be shortened significantly. The battery’s rate of recharge is directly related to how fast the engine is running — many engines need to reach a certain level of rpms before recharging. Additionally, operating the mower at less than full throttle can cause unexpected vibrations, which can severely shake the engine, potentially resulting in malfunction or equipment failure.
Lastly, it can result in more fuel usage. Running your lawn mower at half throttle, for example, causes the engine to lag, and it ends up having to work harder to keep up and uses more fuel to do so. When this happens, the extra fuel circulating through the engine causes washing of the cylinders, creating hotspots where there’s no lubrication. You will end up using more fuel as well as more oil, and the life of the engine could be shortened.
Additional benefits
One of the best benefits of running the engine at full throttle is the quality of the cut. The higher the rpms, the higher the velocity of the blades, creating a cleaner and more uniform cut overall. Additionally, the engine runs at a lower temperature and the cooling fans run faster, which is essential in preventing overheating. Overheating is common when running the throttle at less than full power due to the cooling fans running slower. The transmission works especially hard climbing hills and can lose power and overheat, eventually causing permanent damage.
Another benefit is that the mower won’t bog down when you run into a heavier patch of grass or a spot where the grass is thicker. Otherwise, the grass can be too much and bind the mower up instead. Last but not least, running your engine at full throttle burns fuel more efficiently, giving you a cleaner engine with less carbon buildup. Of course, there are times when you will need to lower the throttle, but keeping it open most of the time is your best bet.
