I've replicated this quote of Doc's from the Expedition thread because I think this is a wider issue for car owners nowadays. Some petrol owners for example have differing views about whether 5W 20 oil should be specified for most 2003-on Honda petrols including the Accord if Honda do not spec it for the Civic Type-R or the Legend or any Honda diesel, I assume for reasons of insufficient engine protection. So is 5W 20 really the best oil out there for my 2.4 Accord? [CJ and I have debated this one until the small hours!] Likewise I understand from elsewhere on the web that Honda MTF III is the equivalent thickness of ATF or 5W 20 and Honda are by no means alone in specifying gearbox oil this thin as Ford among others do as well now. And yet the most reputable aftermarket quality synthetic MTFs are not made this thin. I guess it boils down to the evidence, which the car makers research labs have more of than the man in the street, although no lab can ever replicate the realities of several years real world use. But whose interests are coming first in all of this?