Here at Morton’s Auto we recommend and use Amsoil premium synthetic products. Using a 100% synthetic lubricant will reduce friction among moving metal parts. It accomplishes this by having uniform molecules which flow more freely. Synthetic lubricants are free of having paraffin waxes which thicken in colder temperatures. Amsoil synthetics remain the same consistent viscosity to -40 below zero providing better lubrication on initial start-up. Most vehicles see an increase in fuel economy when synthetics are used.