If your dad can afford 4.5M vehicle fuel consumption is not a big issue to him I guess, with that money you may choose between volvo xc90 2.5 5 cylinder and toyota LC200 4.5 8 cylinder both are diesel fed and seat 7, or you may also check out Mercedes-Benz GLK-Class 3.0 6 cylinder gas and grand cherokee 5.7, 8 cylinders gas but they seat only 5, with suburban or expe i think they're so big unless if he likes big cars, with 5.3 and 5.4 engine respectively they seat 8, both 8 cylinder and drink gas a lot