7.3 gas vs 6.7 diesel Cummins
Fuel cost;
Fuelly has the 7.3 at 11.5 and the 6.7 Cummins at 15.4. Here gas is 4.5 diesel is 4.75 (approx).
Driving 10,000 a year the diesel saves you $828. But diesel maintenance is higher, insurance is higher, and you are out an additional $8,500. The break even point is at 113,541 miles (assume gas price stays same), but this doesn’t account for recoup of higher diesel resell if it’s something you want to factor in.
This is where the diesel wins *if* you factor in higher resell value (this resell value is proportional to the initial surcharge for the Diesel engine, it doesnt seem to be higher in proportion to the initial out of pocket cost, maybe the pre-emissions trucks are an exception to that rule but for how much longer?)
Diesel extra components;
Regardless at that many miles something expensive may go wrong with the diesels extras (turbo, injectors, hpfp, EGR, DEF, DEF heater, SCR) factor in the repair of one of those if your unlucky and you will never recoup that cost.
Granted something could also fail on the gas but it doesn’t have extra components like the diesel the gas fuel pump, injectors spark plugs are chump change compared to diesel parts and the large engine bay allows the willing user to do most repairs without a lift etc.
*This is where I think the gas wins
Engine blocks
The 7.3 is likely a 300k block and internals, it’s extremely robust and even has oil jets bathing the back of the pistons, it’s designed for the abuse. The diesel is likely a 500k block and internals, idk maybe more or less…
*I think this is wash; most non-commercial users trucks’ interiors and body will fall apart much sooner then engine blocks need replacement. This is also where the pro diesel people claim longevity. I just don’t see the benefit when the rest of the truck is dated/falling apart/ unable to obtain replacement interior parts (door handle anyone?) not to mention I’d rather replace the block then get hit with some of the extra component failures.
Vehicle wear and tear;
The diesel weights 800lbs more, the front end and brakes will need more upkeep than the gas. How much? Who knows.
Factoring everything in;
The diesel wins hands down if you get lucky and don’t get stuck with any expensive repair bills (trade that baby in at end of warranty.) Regardless the higher resell “value” is worth approximately 8,500 so you are ahead that much. Put it towards the extra maintenance and/or repairs and if you don’t end up ahead you will likely be even. With that said, diesels enjoy an image of “longevity” from the diesels of the 90s and early 00s. I *think* it’s only a matter of time before people realize how expensive an out of warranty diesel repair is/can be. This won’t hurt new sales but I think it could pull down, to some degree, the higher resell value currently enjoyed by used diesel owners. *unless people stay addicted to the power of a diesel over gas* well that is until electric takes over