well i havent been able to take advantage of it yet, i spun a rod bearing, put 20w-50 oil in for break in, hit some bumps and snapped crossmember bolts, not driving that yet,
but i am getting 17mpg in a 5.7 v8 88 cadillac fleetwood brougham, besides having to fill it up every 3 days at $80 a tank