Synthetic Oil question

I have a 99' Camry LE that just turned over 152,000. The 4 Cylinder engine neither uses or leaks any oil between oil changes. It stays at the same level on the dip stick.
My service manual states that I need to change the oil every 3000 miles.
I am a very conservative driver, the car never tows anything and is never exposed to dusty road conditions, and gets a combination of city and highway driving.
I have been using Mobil 1 High Mileage Full Synthetic motor oil and still changing it every 3000 miles.
My mechanic friend told me that I am wasting expensive motor oil by changing it that oftern. He said, consicering my driving habits and using a high quality full synthetic oil like Mobil 1 that I could easilly go at least 5000 to 7000 miles between oil changes.
I look forward to your thoughts.

I have been using 10k mile oil change intervals in an identical engine with that oil and other synthetics.
If you want to read more than you will ever need to know about synthetic oil and oil changes in general see: http://www.bobistheoilguy.com

Now I'm getting conflicting opinions from my shade tree mechanic friends. Some saying that full synthetics like 0-20W or 5-20W are both fine for my 99' 4 cyl Camry and others saying that these have not been officially approved by Toyota for the 99' 4cyl and advise against using it. :runaround:

Synthetic or dino oil; doesn't your 99 Camry require 5W-30 oil? If the car has the original oil cap, the oil requirement is printed right on the cap.

Mike

Synthetic or dino oil; doesn't your 99 Camry require 5W-30 oil? If the car has the original oil cap, the oil requirement is printed right on the cap.

Mike

Sorry Mike! Yes 5W-30.

Run synthetic, hopefully you already have been. These cars were made for sythetic oil. I do 7500miles with my camry.

As far as the weight of the oil and viscosity, go with what the manual states. If anything you can go a little more viscous in summertime, but I would not go lower than what the manual states (unless you are driving in snow or something).

I use Mobil 1 5W-30 in our Toyota and changing it every 5,000 miles as the hand book suggests.That product is good for 15,000 miles.