Worked this out this morning, thought it might be of interest.
One B16B, one B18C. At 100,000 miles at an average of 50mph, both have been running for 2000 hours, or 7.2million seconds.
At 4000rpm, a B16B has a piston speed of 10.3m/s. That's 74,160km that the piston has travelled over that 100,000 miles.
The B18C at 4000rpm is at 11.6m/s. Over that same 100,000 miles the pistons have each travelled 83,250km.
The B16B has a maximum rod angle of 15.78°, the B18C is 18.56°, owing to it's longer stroke and shorter rod, which exacerbates piston wall wear. That's an increase of 17.6%, which if we attributed that as extra wear in the form of mileage, gives an equivalent piston travel of 98,233km.
Working this backwards 98,233km is 9.54million seconds @ 10.3m/s, that's an equivalent of 132,460 miles on a B16B engine.
Extrapolating that out, 150k on the B18C is equivalent to 199,000 miles in a B16B.
That might be why the big brother likes to burn oil then!