Added MERCON V instead of MERCON LV 2010 Ford Fusion

2010 Ford Fusion

What happens if I add wrong transmission fluid? After adding I noticed it was wrong one. It takes MERCON LV and i put half a quart of MERCON V.

Not sure what if anything would happen. In my opinion you will need to drain and refill the transmission as the two fluids are not compatible.

Transmission Fluid Drain and Refill

Item Specification

Motorcraft® MERCON® LV Automatic Transmission Fluid

XT-10-QLVC (US); CXT-10-LV12 (Canada)


NOTE: In order to completely clean the torque converter, this procedure needs to be carried out 3 times.

  1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Jacking and Lifting.
  1. NOTE

    NOTE: If an internal problem is suspected, drain the transmission fluid through a paper filter. A small amount of metal or friction particles may be found from normal wear. If an excessive amount of metal or friction material is present, the transaxle will need to be overhauled.

    Remove the transmission fluid drain plug and allow the transmission fluid to drain.


  1. Install the transmission fluid drain plug.
    • Tighten to 12 Nm (106 lb-in).

  1. Fill the transaxle with clean transmission fluid.

  1. Start the engine and let it run for 3 minutes. Move the range selector lever into each gear position. Repeat Steps 2, 3, 4 and 5 two more times.
  1. After the transmission fluid has been changed a total of 3 times, using the scan tool with the engine running, check and make sure that the transmission is at normal operating temperature 85-93°C (185-200°F). Check and adjust the transmission fluid level and check for any leaks. If transmission fluid is needed, add transmission fluid in increments of 0.24L (0.5 pt) until the correct level is achieved.

MERCON LV ” Low Viscosity” is not compatible with MERCON V. The LV is supposedly a “lifetime” fluid, so I’m guessing it’ll be a while before we find it on shelves at Pep Boys. And reading the text, it looks like “anti shudder” and “friction modifiers” are the Big Deal with this stuff.


Mercon V was developed in the 1990s and was one of Ford’s most commonly used transmission fluids until it was phased out in 2008 in favor of Mercon LV. However, Mercon LV and Mercon V are not compatible, so any Ford vehicle manufactured before 2008 requires Mercon V.