The user's guide to my 130 series B&S engine (garden cultivator) says: 10W-40 can be used if 10W-30 is not available at your location. So, if you fit to the 10W-30 oil temperature interval then 10W-40 probably can be used. I have been using SAE30 up to now. Now I am planning to switch to 10W-40 as I want to use the machine in the winter as well.
The 15.5 Briggs does not have an oil filter.
what weight oil for 6.5 engine
Click the link and find your engine for the exact capacity.
what grade of oil on this engine
A Briggs and Stratton 17.5 horsepower engine can use any type of small engine motor oil. A heavy duty motor oil is recommended.
Briggs and Stratton is a select brand of lawn mower. When oiling one's Briggs and Stratton lawn mower engine, it is best to use a high quality oil. One can find such an oil at their local home improvement store, such as Home Depot.
1ml
There are a couple different oil filters that fit a Briggs and Stratton 24 hp engine. The most common oil filter is a PE 105.
Briggs & Stratton part # 491056 NAPA filter # 1348
10w30 0r 10w40 both seem to work well.
You can get that info on the Briggs and Stratton website. Just go to: http://www.ereplacementparts.com/briggs-and-stratton-parts-c-16758.html?gclid=CPCZj4vGr58CFZdM5Qodp3bDsA and enter your engine model number.
Briggs and Stratton recommends SEA30 oil.