Do synthetic oils really work?
Yes, but. More specifically, most auto manufactuers accept synthetics, but disagree with the extremely long oil change intervals claimed by oil manufacturers. Auto manufacturers recommend that you continue to change oil at the intervals recommended in the owners manual for your car. Even if you decide to try the longer intervals, at least change the oil filter at regular intervals, as synthetics get just as dirty as conventional oils. Synthetic gear lubricants for manual transmissions are another matter entirely; Amsoil, Redline, and AGIP are very highly regarded and very effective. Mobil 1 synthetic gear lube gets mixed reviews, however.