Every gear head knows that synthetic motor oils deliver a higher level of protection than conventional oils, but the high-tech slippery stuff has a downside when it comes to older engines. Quite simply, it’s just too slippery. A well-worn engine will burn more full synthetic oil due to leaks. That’s why the oil manufacturers initially used conventional oil or synthetic blends in high mileage products, including Quaker State Defy and Valvoline MaxLife Synthetic Blend.
There’s a trend underway to replace the blends with specially formulated full synthetic oils, like Mobil 1 High Mileage and Royal Purple HMX. Valvoline has entered the fray with their new Fuel Synthetic with MaxLife Technology.