Jeff,
Your car fuses are either under the bonnet or inside the cab where it is warm & dry all the time
Your mowers fuses are out in the open , even if you keep it garaged overnight , you will get condensation.
Unless you have greased the fuse box & the fuse you will get corrosion .
All metal oxides are poisonous, abrasive , electrically & thermally insulating .
Thus when power is pushed through a fuse it causes a voltage drop with increases the current which blows the fuse.
All of the blade & pin style fuse holders are "self cleaning" which is PR speak for scrapes the crud off when pulled out & pushed back in .
I could go on about corrosion currents generated by the internal stresses locked into the parts during manufacture but very few will understand & I do not get paid to teach people the physics that they should have learned in high school