I also run Amsoil 5w 30 iwth Amsoil in all our cars. Use the "Signature Series" extended life version for 25,000 miles…but still change it at around 3,000 - 4,000 mile intervals as that's usually about one year. So I use time more than miles.

http://www.amsoil.com/shop/by-produc...tic-motor-oil/


Amsoil also has another formulation for older cars and those with higher oil consumption when running lower viscosity oils. You'll recall some here have switched to Rotella oil as it's a thicker viscosity, and some say they've had less oil consumption.
http://www.amsoil.com/shop/by-produc...ion-motor-oil/


Amsoil is sold thru a network of representatives (can't think of what they're called), but I've seen it in some small privately owned "mom & pop" auto parts places. You can find a rep by going to Amsoil's site.
Downside is you have to pay shipping, unless you find a rep that's close enough to let you pick itup in person, or pick it up from an Amsoil warehouse. I've picked mine up in a Las Vegas warehouse, saved a ton of shipping.