This thread amuses me a little as here we are on this site talking about the mods we've done which Ford would never approve but we are trying to get the specific oil that Ford recommends. Has no-one here used non-genuine parts on their car? (I'm not having a go at anyone, so please don't take offence, just my 2c worth on the debate).
In my dealership experience, most dealers have a deal with a certain oil supplier and buy in bulk from them and that is what they use in all vehicles they service, they don't as a general rule, use the Ford recommended or supplied oil.
Call me cynical, but IMHO the only reason Ford recommend that specific oil is due to a marketing deal they will have done with the oil manufacturer, not because it is the only oil that is suitable to the FiST engine. Ford have possibly done all their testing with this specific oil and all their emission and power specs were derived using this oil and to ensure that it still maintains these combined outputs they would recommend the same product. It would be interesting to see the actual engineering reasons from Ford behind the oil they recommend. I might be wrong, but if you use a good quality brand oil that meets the correct viscosity grade you should be safe.
Hypothetically would it still be the case, if someone comes up with a new advanced oil that would double the life span of an engine, gives increased mileage, reduced emissions and increased power that it wouldn't be suitable because it doesn't have Ford's specific number on it?
For what it's worth, at the 3k mark I've changed my oil and filter (which Ford don't specify as needing to be done) with a Ryco filter and Nulon semi-synthetic oil of the correct grade (but doesn't have Fords specific number printed on the back of the bottle) and will then change it at 10k and every 10k after that with a fully synthetic oil. It might be more often than the recommended intervals but much of the reasoning behind 15k service intervals is to reduce the marketable ownership costs of vehicles over their expected lifespan for the general public, who don't care as much as we enthusiasts do about their cars (yes oils and engine materials have gotten better over time, making them last longer) and doing it more often isn't going to harm the engine (just the environment).
