Got a gearcase that’s running hot? Consider using synthetic gear lube. Larry Ludwig, chief chemist with Schaeffer Oil, says synthetic oils reduce gearcase operating temperature in two ways.

Despite being less expensive than its competitor's synthetic offerings on Amazon, the company's self-branded oil is well-regarded among drivers. At under $25 for a five-quart bottle and with over ...

from engines to complex gear sets — engine oil also comes in conventional and synthetic varieties. Both types of oils are derived from petroleum and crude oil. However, synthetic oil contains ...