Ford made plenty of diesel engines before the latest Power Stroke. 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 long time ago, and there’s been a long line of Ford diesel engines since.
Ford diesel engine history
6.9L IDI Engine 1982 – 1987
It all began in 1982 when Ford released its first diesel engine designed for the general public. With a displacement of 6.9L, the naturally-aspirated powerplant churned out 170 hp and 315 lb-ft. Not a lot of grunt by today’s standards, but 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
The year 1987 ushered in what’s considered 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. The engine block was also strengthened and the cylinder heads were completely redesigned. 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 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 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 the first Power Stroke 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 engine was completely different from the IDITs. 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 turbocharge air. It also got an electronic fuel pump, a new turbo with higher boost pressure and higher injection pressure. This engine is touted by many diesel aficionados as being the best ever. It pumped out 235 hp and up to 525 lf-ft, and was known to last well over a quarter million miles.
6.0L Power Stroke 2003 – 2007
The dark times 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. Unfortunately, a series of wallet-draining problems – such as blown head gaskets and faulty EGR coolers – continuously haunted the 6.0L.
6.4L Power Stroke 2008 – 2010
Plagued by reliability issues, the 6.0L was dumped after only 4 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 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 piezo electric injectors. Boost came from twin sequential turbochargers. Power output from the 6.4L was an unprecedented 350 hp and 650 lb-ft. 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 alliance.
6.7L Power Stroke 2011 – Present
Ford decided to go solo without Navistar, introducing the 6.7L Power Stroke in 2011. The all-Ford engine was a fresh design, with a DualBoost variable geometry turbo. A water-to-air intercooler provides that turbo cool, dense air. As with the previous engine design, the 6.7L uses a common-rail injection system. Output is a stump-pulling 390 hp and 735 lb-ft. So far, the 6.7L has been pretty reliable, although it’s nowhere near as durable as the 7.3L build during Ford’s glory years.
Looking toward the future
For better or for worse, Ford makes the best selling trucks in America. Up until now, the automaker has only offered diesel engines in heavy-duty trucks, like the F-250 and F-350. For 2018, it’s adding a first-ever diesel F-150 to the lineup. The truck’s engine is a 3.0L Power stroke, making 250 hp and 440 lb-ft. It’s scheduled for release this spring.