My suspicion is that the Triumph branded Mobil oil and the MX-4T are very similar oils. Maybe not exactly the same but similar at least. (wouldn't it be funny if "MX-4T" stood for something like "Motorcycle Oil 4 Triumph")
Anyway, use what you'd like but remember Triumph specs their branded oil (of course) for all of their bikes. So this oil is designed with the idea in mind that it is going to be used in 600cc sport bikes. You can't pull out of your driveway on a 600cc sport bike without pulling 8000 rpm. Normal riding on a bike like this would be like riding your BA or Speedy at red-line all the time and as such, they tax an oil to a far greater degree than our twins do.
To me, $50 a gallon racing oil for a bike that runs between 10-14k rpm most of the time, okay. For twins spinning at 4-5k - overkill.
Just my $.02,
Keith
