: Why lawnmower mufflers suck


Car/Truck mufflers do amazing work muffling noise. A car is nearly silent when running with a muffler, compared to what it would sound like with open manifolds. When I fire up my Honda push mower, the whole neighborhood knows about it, and it’s actually kinda quiet as mowers go. So eli5 : Why can’t lawnmower mufflers work like automotive mufflers?

In: 29

Well a car muffler is about 100x larger. That’s why. The sound bounces around way longer before exiting the muffler. If you attached a larger muffler on a mower it would be quieter, but it would also be more expensive and much heavier to push around.

Too much backpressure on the small motor that cannot make enough pressure to operate a large restrictive muffler

Mainly they don’t work as well because they don’t have to. Regulations on auto noise is much more limiting than on lawn equipment. If lawn equipment manufacturers were required to meet a lower decibel level, they would invest in the engineering and materials to meet those requirements.

It is probably due to consumers not willing to take on the cost value for development. Will most people pay $100+ dollars more than any other model available just because it claims to be a little quieter and looks odd and heavy compared to what you expect a mower to look like?

While many here claim it is a physical constraint, Honda’s small power generators are much quieter than any combustion lawn mower. The existance of electric lawn mowers is probably also a contributing factor.

It’s a lot cheaper to buy an electric lawnmower than to put a car-grade muffler on a lawn mower. Nobody would spend 2-3X as much on a “quite mower”. Car noise is easier to control, because cars are huge and you can have space for all sorts of dampening devices, water cooling, exterior panels with sound insulation, … that would’t make any sense in a mower.