I bought a house and with it a Toro 8-32, I think from 1990. The engine is a 8HP Briggs & Stratton. I mow probably about an acre - maybe an hour and a bit total time. During this period the engine seems to burn oil - about 4 ounces based on the fact that the lower end of the dipstick range says "Add 8 ounces". I have been checking the oil when the engine is cold, and adding a bit before each time I use it. I'm using Castrol GTX 5w-30, although I also added a bit of Rotella T Synthetic 5w-40 when I didn't have any of the Castrol. There is no visible blue smoke when mowing, but if I let the mower idle for a bit it'll puff a bit as it idles - and a bigger puff of blue smoke when I rev it back up to mow. Is this a normal amount of oil consumption for this engine? Any comments on choice of oils? I'm also running a bit of seafoam in the gas right now to clean out the carb.