I wouldn't trust an annual change, but I'm a Mobil 1 guy, always have and always will. All the vehicles at our house use Mobil 1 fully synthetic. Both my Jeep and Yukon have over 200k and they have had Mobil 1 pretty much since they left the factory, both dad's RAMs had had Mobil 1 since he bought them new, his last one (2003) had almost 200k before it got totaled and his 2010 has almost 100k or a little over. My sister's Jeep Compass has a little over 100k.
I change them at 5k miles and have never had a problem, pulled the pan on the Jeep for a rear main and did a valve cover gasket it at 200k was spotless with no sludge. The Yukon, from what I can see through the oil fill, looks pretty dang clean also.
Would I got more than 5k miles though? No, because I'm also pretty stubborn about that sort of thing, I have gone about 6000-6500 before because I could not get time to change it but I don't do that often.