Ford made plenty of diesel motors before the Power Stroke diesel engine. In fact, the automaker started putting oil burners in passenger trucks way back in 1982 — the same year Michael Jackson released his Thriller album. That was a few decades ago, and there’s been a long line of Ford diesel engines since.
Ford Diesel Engines History
Below we’ve outlined the eight motors that feature prominently in Ford’s diesel engine innovations. From the very first to the very latest, these Ford diesel engines are the muscle behind some of Ford’s most memorable diesel trucks.
6.9L IDI Engine: 1982-1987
It all began in 1982 when Ford released its first diesel engines designed for the general public. With a displacement of 6.9L, the naturally-aspirated powerplant churned out 170 hp and 315 lb.-ft. of torque. And though that’s not a lot of grunt by today’s standards, for the 1980s those were impressive numbers.
The engine was a joint venture between Ford and International (which is now Navistar). It got fuel from a Stanadyne DB2 rotary distributor fuel injection pump and had a sky-high compressions ratio of 20.7:1. The fuel system also gave the engine its name – IDI stands for indirect injection.
7.3L IDI Engine: 1987-1993
1987 ushered in what’s considered to be the best Ford diesel engine ever — the 7.3L. When building the new engine, Ford kept the same stroke as the 6.9L but increased the bore. Ford also strengthened the engine block and completely redesigned the cylinder heads. One thing was missing though — a turbocharger. The engine made 185 hp and 338 lb.-ft. without forced induction.
7.3L IDIT Engine: 1993-1994
Finally, in 1993, the 7.3L engine got its long-awaited turbocharger. The internals of the engine were upgraded to handle the boost pressure created by the turbo. Somehow though, the engine didn’t make much more power than its predecessor. Output was only 190 hp — up a mere 5 hp from the naturally aspirated 7.3L. Torque didn’t increase at all. But it didn’t really matter, because Ford was working on a brand new engine that would revolutionize the industry.
7.3L DIT Power Stroke: 1994.5-1997
Ford introduced its first Power Stroke engine in late 1994, setting the benchmark for light-duty diesel truck engines. As before, the new engine was a collaboration between Ford and Navistar (formerly International). Although displacement stayed the same, the Power Stroke diesel engine was completely different from the IDIT.
It featured an electronically-controlled, direct fuel injection system capable of making up to 21,000 psi. Engine output was a stout 210 hp and 425 lb.-ft. — finally, enough muscle to get the job done.
7.3L DIT Power Stroke: 1999-2003
In 1999, Ford revamped the 7.3L Power Stroke, making it even better. The revised engine saw the addition of an intercooler to create denser turbocharged air. It also got an electronic fuel pump, higher injection pressure, and a new turbo with higher boost pressure. This engine is touted by many diesel aficionados as being the best ever. It pumped out 235 hp and up to 525 lb.-ft. of torque, and was known to last well over a quarter-million miles.
6.0L Power Stroke: 2003-2007
The dark times of Ford diesel engines began in 2003. Faced with more stringent emissions standards, Ford introduced its least reputable diesel engine to date — the 6.0L Power Stroke. This engine was so bad that Ford and Navistar eventually went to court over it.
It featured a glut of emissions equipment never before used, such as an exhaust gas recirculation (EGR) valve. A brand-new variable geometry turbo was also installed, bumping power up to 325 hp and 570 lb.-ft of torque. Unfortunately, a series of wallet-draining problems, such as blown head gaskets and faulty EGR coolers, continue to haunt the 6.0L.
6.4L Power Stroke: 2008-2010
Plagued by reliability issues, the 6.0L was dumped after only four years of production. In its place, Ford introduced the 6.4L. This new engine featured beefed up internal components as well as a new fuel system.
Previous Power Stroke diesel engines had always used hydraulic electronic unit injection (HEUI). This design relies on engine oil pressure for fuel injector operation. By contrast, the 6.4L was introduced with a common rail system fitted with piezoelectric injectors. Boost came from twin sequential turbochargers.
Power output from the 6.4L was an unprecedented 350 hp and 650 lb.-ft. of torque Although it was a step up from the shoddy 6.0L, the 6.4L had its own problems. After building two bad engines in a row, Ford and Navistar decided to part ways. The 6.4L was the last diesel engine to be built by the partnership.
6.7L Power Stroke: 2011-Present
In 2011, Ford decided to go solo without Navistar, introducing the 6.7L Power Stroke. The all-Ford engine was a fresh design, with a DualBoost variable geometry turbo. A water-to-air intercooler provided the turbo with cool, dense air. As with the previous engine design, the 6.7L uses a common-rail injection system.
Output was a stump-pulling 390 hp and 735 lb.-ft. Current turbocharged configurations can be had with an even more powerful 475 hp and 1,050 lb.-ft. of torque. So far, the 6.7L has proven to be pretty reliable, although it’s nowhere near as durable as the 7.3L built during Ford’s glory years.
Ford Diesel Engines: Looking Toward the Future
For better or for worse, Ford makes some of the best-selling trucks in America. For a long time, the automaker only offered diesel engines in heavy-duty trucks, like the F-250 and F-350. In 2018, it’s added a first-ever diesel F-150 to the lineup. The. F-150 came standard with a 3.0L Power Stroke, making 250 hp and 440 lb.-ft. of torque. But with EVs like the F-150 Lightning on the horizon, what the future holds for Ford’s classic diesel engine is anyone’s guess.