Its in the manual....

pg 103 of the '06 manual.....

GPSman1 wrote:

"With full synthetic oil, you can change oil every 15,000 miles."

And

"I used Mobil 1 and took it 15,000 miles the second time, and the oil was still in good shape. Visually, it was still clean, dark-tan colored, and translucent, after 12 months and 15,000 miles."

This he wrote in another tread, but I thought of restating it here.

Even though I agree that full synthetic oil last longer than non synthetic oil, I would still not recommend going to 15,000 miles between oil changes. This is mainly because Ford recommends part synthetic and a max of 10,000 miles between oil changes.

When I took my FEH in for the reflash of the PCM, I had about ~9,500 miles on Mobil One 5-20W oil. The Tech said all my fluids looked good, but said my oil looked like it was needing a change. It so happen I was going to change that oil the weekend my FEH broke and had the oil and filter ready to go. I personally would not exceed the max miles of 10,000, even with Mobil One with the low RPM's and amount of EV driving I do.

Does Mobil One oil say it's okay to exceed manufacture specs between oil changes?

GaryG

YES!

In the fine print Mobil reccommends following manufactuer's oil change interval during the warranty period, after that, 5000 miles for Dino oils, 7500 miles for blended oils, and 15,000 miles for extended performance MOBIL 1, no matter what the manufacturer says, and they warrant your car against damage if you follow this OCI.

From Mobil: And this is for REGULAR cars. Hybrids are much more gentle on oil.

To achieve the best peace of mind related to engine protection, many vehicle owners change their engine oils every 3,000 to 4,000 miles. Is this practice rendered meaningless with the advent of the Mobil high-endurance oils?

"Consumers can have peace of mind knowing the guaranteed performance and protection intervals of the Mobil line of high-endurance oils. Mobil Clean 5000, Mobil Clean 7500, and Mobil 1 Extended Performance protect critical engine parts from lubricant-related failure for 5,000/7,500/15,000 miles -- guaranteed."

FYI Mobil Clean 5000 is Dino oil.
Mobil Clean 7500 is blended oil.
Moibil 1 is full synthetic oil.

Mobil Clean 7500, the blended one, would most closely match stock oil.
And FORD says this type of oil is good for 10,000 miles in our special engine situation.