Does anyone know why Fords recommended Trans fluid change interval is
150K miles on my 2012 F150 and 30K miles on my 2008 Expedition. Wow - can they be that different?

John Mc

 

Aren't they two different transmissions that take two different fluids (Mercon V vs Mercon LV)?

 

150k sure seems like a long stretch.

 

Unfortunately, many manufacturers push their ridiculously high service intervals in order to get the long run cost of ownership figure down. Personally, I think 30-40k on conventional, 60-70 on synthetic is a good rule of thumb on intervals (albeit, I am a bit OCD on maintenance). ZF, who builds the transmissions for many high performance vehicles and designed the current F150's transmission (http://en.wikipedia.org/wiki/Ford_6R_transmission), has even been trying to downplay the 'lifetime' fluid ratings and specifies that the definition of lifetime has been left to the car/truck manufacturer (http://blog.bavauto.com/wp-content/u...ce-letter1.pdf). For high loads or spirited driving, they recommend changing even the high performance synthetic fluids every 100,000 km or 62,000 miles. If you run conventional fluids, 30-40k is probably okay for the Expedition (maybe stretch to 50-60 if you swap to synthetic), but I think the 150k for the F150 is far too high. Since that truck uses the Ford 6R80 which is based on the ZF 6HP line, I would follow ZF's recommendation of ~100,000km.