I have been wondering about this for a while, and it came to a head when I accidentally changed the fluid in a 2006 Escape with Mercon V. I went ahead and flushed the system and refilled with Mercon, then began wondering if I had done that prematurely. So, I did a little digging on the internet and found that Ford has officially stated that it is ok to use Mercon V to service Mercon transmissions. The following is a clip from a trade magazine where the Ford ATF engineer was presenting information to SAE...

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For over a decade, Ford Motor Co. has licensed its trademarked Mercon automatic transmission fluid for the service-fill marketplace. Last week, the automaker announced it is going to retire that specification, in a move designed to encourage the lubricants industry to embrace its replacement, the stringent Mercon V spec.

Speaking April 4 in Dearborn, Mich., to the SAE Technical Committee 3 on ATF, Gear Oils and Greases, Ford’s Chintan Ved announced that effective July 1, no new Mercon licenses will be issued. All remaining Mercon licenses will expire on or before June 30, 2007, leaving a clear field thereafter for Mercon V.

Ved, based at Ford’s Automatic Transmission New Product Center in Livonia, Mich., is the company’s lead development engineer for ATF. He noted that although his company has recommended Mercon V for all vehicles for the past seven or eight years, most Ford models on the road continue to be serviced by Mercon. Mercon V, however, is a far better product that more closely resembles the factory-fill ATF which Ford has used for over eight years. It requires the use of a more shear-stable viscosity index improver, and Group II or Group II-plus base oil to meet its viscosity and oxidation targets.

“All transmissions recommending Mercon ATF can now be serviced with Mercon V,” Ved later told Lube Report. “Mercon V is a tighter specification, requiring better anti-oxidation, antiwear and anti-shudder properties from service-fill ATFs. We are doing this because we want to ensure our customers get the better fluid.

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