A 150 mile mostly motorway journey on my near 2000 mile 2016 car left me with a variety of observations. I will first say I was wearing an open face motorcycle helmet and earplugs.
Around 55 mph there is a transmission whine which occurs in little over a few miles from start although not obtrusive. Not dissimilar to that of a car with slightly worn transmission. After just 10 miles of motorway speeds, at between 76 and 81mph indicated there was a different pronounced bevel box wail which remained at any steady speed between those figures - not as loud as when first running in car though. I can be precise because traffic was continually taking me through that speed band. At 82mph the noise dissappeared with a very noticeable transition. Over the length of the journey the wail did vary getting a little less, possibly as bevel box temperature dropped.
Thank heavens the speedo over reads though
