reliability

I'm looking to buy a 2017 T6 Caravelle to use for commuting about 250miles per week. I'm going to clock up the milage pretty quick and want the most reelable engine long term. I know I'll get about 10mpg more from a diesel but am thinking that a petrol engine may give better long term...

As usual, some give a bad rap, heard it's exy to run and get parts for?? Also checking out Toyota Hiace.