Long run improves running - why?

[bmcecosse]

Indeed they did - but the engines were NEW then !! Folks soon moved up to Castrol XXL which was SAE 40, as a bit of wear set in.

[mike.perry]

Well my Traveller certainly does not sound sweeter, smoother, quieter etc after a long run. The diff whine reaches a screach, the gearbox 1st gear bag of spanners is available in other gears, the main bearings are definately rumbling and the oil pressure is struggling to stay above 30psi.
And just to add to the din of the pancake filters and LCB exhaust, the body crashes over every pothole and road hump

[bmcecosse]

Sounds about right - and ears are ringing anyway from the roar of the exhaust.......