Use what you like but I can tell you this, modern car oils don't contain the zinc and phosphorus anti wear additives that dedicated 4T bike oils do.
Cars don't share the same oil between engine and gearbox either.
4T bike oils are made to the old SG formula, car oils have gradually reduced the "good" additives to meet constantly evolving emissions regulations and are up to SM now
2007 Cagiva Mito.
1980 and 1978 Ultra lightweight Yamaha SR500 Cafe Racers
1967 500cc Ultra lightweight Triumph Daytona Cafe Racer