Wow I really cant believe some said the following "Summary: The 4d56T is a hard worker. If you want a performer, get a later generation TD or a petrol engine. Diesels are not as easy to "upgrade" as petrol's." Your right the 4d56 is a hard worker. But the hole Diesels are not as easy to upgrade as petrol's it 110% WRONG. Dollar for Dollar diesels respond better to upgrade parts than there petrol brothers. My 4d56 has been running 25PSI of boost for 6 months now with out a issue, it has a home made snorkel, and a custom made 3.5 inch exhaust. And the best part is im back into the 20-25 MPG range with 35 inch tall BFG MT's. I would put my 4d56 up against any other petrol version any day of the week and i will make more power, get better mileage, and have less trouble doing it. There is nothing more reliable than a simple diesel. O yeah in case i forgot i run used fryer oil in my truck to at a 50/50 blend and am getting ready to install a new intercooler or add a second stock style intercooler.