I live in San Francisco (mild temps) and have a '99 4runner with 110k on it and was thinking of switching to Mobil 1. I drive mostly city miles with a couple 300 mi. road trips every summer, and so far I've been using standard Pennzoil 5-30 every 3,000 mi. Should I switch to 10-30 since I have over 100K miles, and should I forget the synthetic and stay with the 3,000 changes? I just hate messing around with getting the damn oil filter out! Plus Costco has Mobil 1 for $4/quart.

Robs10, here's a post that will give you some insight on oil and oil change frequencies. http://www.tundrasolutions.com/forums/4runner/12920-oil-changes-and-synthetic-oil/

I have 137,588 miles on my 2000 4runner Limited 4x4 and have been running Amsoil 5w30XL or 0w30 and my vehicles been running just as good or better then when I bought it at 63,000 miles. The week I bought the 4runner I ran a Amsoil flush then filled with 5w30xl and changed the spark plugs to the Denso Iridium version of the OEM Denso plugs. I just looked at my oil today with 11,435 miles and it's a semi clear light brown color, I am changing it out later this week along with the fuel filter. Mobil is cheaper but atleast with Amsoil you are supporting a American family owned company