No mower will last if not looked after
The big commercial mowers usually have more grease points and are easier to maintain.
Residentials are made no maintenance which is why they fall apart so quickly
Eg I have a lot of Time Cutters ( residential ) and Z Masters ( Commercial ) in my repair run
Time Cutters have deck wheels that run directly on the bolt that supports them so the bolt get eaten through
Z-masters deck wheels run on shaped bushes so the wheels last longer and the bolt does not get worn through
Time Cutters have a deck tension pivot that wears out & uses friction washers that require regular replacement .
Z-masters have a long large diameter bush with grease nipples that will last forever if it gets 1 or 2 strokes of grease a season
Time cutters either have no spindle grease nipples or they are under the deck
Z-Masters have the spindle grease nipples on the end of the hollow spindle accessed directly from the top
Time Cutters have bolt on pulley covers on the deck that need to be removed to clean the debris away from the pulleys & belt ( common fire starters )
Z- Masters have a slide off cover , removed in 15 seconds makes belt replacement a breeze
Time Cutters come with FR engines that have a very substandard filter
Z Masters come with FX engines fitted with 2 stage Donaldson air filters that on residentials will probably never need replacing and extends engine life from better filtering .
Commercial mowers tend to use large diameter idler pulleys
Large diameter = revolves slower = last a lot longer and large diameters also = less back bending of the belts so longer belt life
Chalk and cheese the difference between commercials & residentials
Even old clapped out commercials are usually better than brand new residentials .
Then there are things like the hydro drives.
Most commercials will have a drive with external oil filters & easy accessiable filling ports
Residentials generally require you to remove the hydros from the mower to change the oil
Commercials generally use thicker wider blades that if sharpened each season will probably out live you
Residentials have thinner blades, easily bent or broken .