Okay, now that everybody has put in their two cents, I'll clarify what I originally meant.
In 1997, I bought an MTD mower on clearance from Target for $70.00.
Over the years, I ran everything, including HD30, HD40, 10W-40 and mostly 20W-50.
The Tecumseh endured for what I calculate as more than 400 hours based upon the size of our yard, the length of time it takes me to mow it and the number of years I used the machine. Just for reference, nobody else in our subdivision push mows their yards. Everybody else uses a lawn tractor or ZTR. It still ran when I put it on the curb on trash day, although the mower as a whole had served its purpose and owed me nothing and had enough little issues that it was time to let it go.
It didn't last long on the curb either.