Your goal is to minimize the amount of friction generated by the wheel bearing. This can be accomplished by the use of quality grease specifically intended for high temperatures. Be careful not to overdo how much grease you apply, though, as this can result in overheating because of friction that can’t appropriately be dissipated. With repeated overheating incidents, damage can occur.
And, even though proper application of grease will help these parts last longer, they will eventually need to be replaced. Typically, you should check and maintain your wheel bearings every 25,000 to 30,000 miles. An average sealed wheel bearing lasts 85,000 to 100,000 miles although some can last as long as 150,000 miles.
A note about gas mileage: If you surf around online auto forums, you’ll find conversations about whether or not bad hub assemblies and/or wheel bearings can have a negative effect on gas mileage. As on many car-related topics, there isn’t clear consensus, with some commenters noticing an improvement after hub assembly 43560-26010 repaired.