Would like to buy one 5 quart jug of oil instead of separate quarts for oil changes. I have a Riding mower with a Kohler that calls for 10w30, a cheap push mower that also calls for 10w30 and a cheap snowblower that calls for 5w30. I live in northern connecticut so temperature swings but nothing too extreme. Would 5w30 provide enough protection for the mower? Would 5w40 be an option?