I spoke with a Briggs Tech Rep becuase their new oil recommendations state the following.. (and it dosen't all add up). -They say to use B&S 30wt down to 40*F which is fine; but they think from "extensive testing: it is the overall best choice for their engines with the recommended OCI's. -They say the engines will burn oil if a conventional 10W-30 is used due to the engines having inheirently big clearances. -They now say you can use B&S 5W-30 synthetic from below 0*F to 104*F with no mention of the engine burning oil. -They no longer mention using 10W-30 synthetic like they used to. I plan to give Amsoil ASE a go...but these folks are in the dark ages. Why loose tolerance engines>? Oh...right...Honda and Kawasaki are much tighter and do well on synthetics with no oil burning issues....almost forgot..