My 1995 3.0L Caravan has 105k miles on it and I am not having any problems (oil consumption is normal, etc.).

I was wondering if I should continue to use 10W30/10W40 oil (I live in southern Califiornia where it never really gets very cold)... or if I should switch to either synthetic oil (Mobil 1, etc.), or what is now being marketed as "oil for 100k+ engines"?

Would I be able to extend the life of the engine by switching oils?

Take a look here, it will answer any question you could ever have about oil: http://theoildrop.server101.com/cgi/ultimatebb.cgi

Take a look here, it will answer any question you could ever have about oil: http://theoildrop.server101.com/cgi/ultimatebb.cgi

Why mess with something that has worked for you. Sounds like you change the oil and filter regularly and she's not using oil. I have 140k on my old van and she doesn't use oil. I won't change her diet if shes not complaining..... my 2cents

I would tend to agree with CobraSam, while sythetic oil is good for vehicles, sometimes it is better to stick with what you are using. Sometimes by changing styles of fluids in an automobile can cause lubrication difficulties such as gumming up or freezing. So listen to Cobra Sam and stick with what you've been using and keep changing on a regular basis.

An alternative to synthetic, if you wanted to add life or better gas mileage, is to add a quart of "Slick 50" with your next oil change. This will help clean out gummed up spots and lines!