Its not so much the fact that a Perkins is so much different from a Cummins, its the fact that a 4bt displaces 4l. Cummins is famous for 1l per cylinder. Another thing is, if i remember right, 4bt stands for 4 cylinders, b series, turboed. The perkins at hand here is a 192, 3.1L, 16:1 compression (low) at a grand total of 62 hp. Not a real beastly engine. The smallest 4bt i could find was 3.9l, 105hp, 17.5:1 compression. The 4BT is larger, 48 cubic inches, and has a larger compression ratio. Because it has a) a turbo, and b) a higher compression ratio, it burns the fuel more efficiently. Horsepower differences make the 4bt a more efficient engine in general because it has additional horsepower to drag the jeep around with. An underpowered engine will suffer in the gas mileage sector of performance. So, basically saying one diesel swap is similar to another diesel is a bad practice. anyone correct me if im wrong.
My jeep gives a whole new meaning to the phrase, Just Empties Every Pocket!
1975 Jeep CJ5 258 TBI EFI, T-18, D-20, D44 rear, 4.11.
1992 Jeep Cherokee 4.0L, AW4, NP231 October 2009 - August 2012
1998 Jeep Cherokee 4.0L, AX15, NP231 - August 2012