New Briggs and Stratton Oil Recommendations

Briggs and Stratton is now saying that; You can determine the Proper Oil Viscosity
for your 4-Cycle Mower; By Evaluating your Local Climate's
Average Outdoor Temperatures During your Mowing Season.

They State that Their Small Engine Oil Type Recommendations are:

•Use SAE 30 in warmer temperatures of 40°F and higher

•Use SAE 10W-30 for a varying temperature range of 0ºF to 100°F

• Use a Full-Synthetic 5W-30 Oil if your Mowing Season often sees temperatures above 100ºF Such as Arizona and Nevada

•For Continuous-use, and Commercial Lawn mowing use Vanguard 15W-50 Oil (in Weather temperatures of 20°F to 130°F)

For those who would like to read it for themselves;
This was all found right from Briggs and Stratton website:

https://www.briggsandstratton.com/na/en_us/support/faqs/browse/mower-oil-type-and-capacity.html