Drove it hard since my last oil change with 10w-30 Valvoline synthetic High milage.
This includes 2 trips of 720 miles each.
During these trips long stretches at high speed and one hours drive at each end with very hilly driving using the manual transmission control mode to use high engine revs up the hills and get engine braking for this 5100 lbs (plus driver and the vehicle full of luggage maybe 500 lbs payload)
Used no amount of oil that I can measure which for as much high revs I had been using is pretty nice.
Oil also still looks clear and golden despite the high revs its seen so far.
Pretty happy with that.
PS: Why am I on 10w-30 not 5w-30 as speced by factory?
Well its springtime and soon summertime in the US.. there is no need for the "5w", in 5w-30, any 10w-30, or for that matter even 15w-50 will be easily pumpable at ambient temp cold starts.
but the 10w-30 means there are fewer VIIs used to create the oils multivis behavior compared to a same formulation 5w-30... which means it will make less varnish ( fewer VIIs) and more resistant to oxidation (thicker base lube stock) and still stay in grade better than a 5w-30 with all other things being equal.
Ultimately i want to extend my oil change intervals from 5000 miles to 6000 miles or even 7000 miles.
And for that I need a stable oil and the small interval between both numbers promises this.
