My experience with debating on this topic has shown me that people tend to adhere to their beliefs on the subject as though it were a debate on religion.
I totally agree with Joe Black on the subject and Tone points out the importance of how readily available a product is to a potential consumer as well as oil analysis when dealing with extended change intervals.
I for one don't know off-hand where in my area one could buy either Amsoil or Royal Purple...as I've not crossed paths with either of these products. Mobil 1 Engine oils are readily available at WalMart, Sam's Club, Advance Auto, AutoZone, etc...
I use Mobil 1 SuperSyn in both my vehicles but I extended my change interval on the Fiero from 3k to 4.5k as it is a daily driver and accumulates lots of miles...right now grand total stands at 190,000 miles with oil analysis done after extending the change interval and revealing no negatives.
The VehiCross on the other hand tends to be driven on missions of relevance and recreation and is therefore not my daily driver.
Plus...she is My BABY, and gosh darn it all if I want to spoil her with 3k mile synthetic oil changes..so be it! My only complaint is that the local oil change facilities only offer either Pennzoil or Valvoline and the Dealer uses Quaker State. Also I use either Purolator's micro filtration available at Advance Auto or Mobil 1 filter available at AutoZone....so therefore....have ended up changing the oil & Filter myself!
[SIGPIC][/SIGPIC]"If its fast and reliable, its not cheap;
if its fast and cheap, its not reliable;
if its cheap and reliable, its not fast."
If love is blind, why is lingerie so popular?