I have a 2001 F-350 7.3 litre powerstroke with 200K on it. It seems to be down on power especially from 45 to 60 mph. When it is in overdrive at thse speeds you can't hear the turbo spooling at all. I have had the turbo replaced, the injectors checked twice once by my mechanic and once by the ford house. Both say everything looks fine. Both say the fuel pressure is more than adequate. The fuel filter gets changed every time I change the oil and I have a clean K&N air filter. Does anyone have any ideas? I would appreciate any suggestions. I love the truck but get irritated every time I try to pull osmething or even pass a car due to the lack of power.

I suspect a turbo problem. You probably are not using full synthetic HDDO and the turbo is acting up at high speeds. This link may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281

I suspect a turbo problem. You probably are not using full synthetic HDDO and the turbo is acting up at high speeds. This link may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281

So should I use a different oil or what do u suggest. The ford house and my mechanic said that the turbo is putting ot plenty of boost. I am not very smart when it comes to diesels.

Absolutely. I would use one of the SAE 5W-40 full synthetic heavy duty diesel oils listed in the link. Look into a bypass filter system, which makes using synthetics very cost effective. Still use the Motorcraft FL-1995 filter as well.