I imagine cost might be the driver for someone to select a multi vechicle fluid, however i have a local vendor that has access to genuine Dexron VI and our local Canadian Tire sells licensed Dexron VI. Between those two and a pan drop every 5 years, my Chevy 6L-90 has 260,000 miles. However, another data point is that the vehicle does a lot of commuting on highways with no stop and go traffic, plenty of cooling and very little shifting on its 40 mile daily route. City driving with constant shifting in hot weather would definitely be harder on the transmission, masking any “ scientific” results. I’m not interested in experimenting with a one size fits all solution. To each his own.