The 2.5L is a good engine although its getting long in tooth, but a work horse for sure. Its also port injected (wet intake valve) not direct injected (dry intake valve) like the ecoboost engines so the carbon build-up one the back of the intake valve won't be an issue as the fuel injected in the intake port tends to keep the backside of intake valve cleaned off. In 2011, the 3.7 Cyclone V6 became a standard engine in the Ford Mustang replacing the 4.0L Cologne V6. It was commonly known and marketed as the 3.7L Duratec V6. The 3.7L Duratec has a cast aluminum alloy cylinder block with contemporary architecture. It has a removable rear main seal cover plate and a structural rear sump cast aluminum oil According to the workshop manual, a 2023 model year Transit equipped with a 3.5L Duratec V6 takes 12 quarts (11.36 litres) of 5W30. Yet, the same model year of Transit equipped with a 3.5L Ecoboost V6 takes only 6.0 quarts (5.7 litres) of 5W30!!! The Ford 3.3L Duratec is a naturally-aspirated V6 engine. It features twin-independent variable cam timing (ti-VCT) and fuel is fed via a direct injection system. The unit has a bore of 90.4 mm and a stroke of 86.6 mm ensuring its effective airflow quality. It has a compression ratio is 12.0:1, which translates to efficient fuel combustion. This means that their estimated lifetime shouldn’t be less than 250 000 miles or about 400 000 kilometers. Of course, you can make this average mileage shorter or longer by controlling the quality of regular service and maintenance. Once you forget to change the oil in your 3.5 Ecoboost engine on time, you get a shorter life of the unit. The 2.7 EcoBoost has aluminum cylinder heads with integrated, water-cooled exhaust manifolds, dual overhead chain-driven camshafts, four valves per cylinder, and roller finger followers. The engine features variable intake and exhaust camshaft timing. A considerable amount of power and torque is achieved with the help of a pair of turbochargers. This Duratec 3.5/3.7 engine series is not at all picky about brand/grade of lube; they pretty much wear easily regardless what's in the crankcase (within reason, of course). If not for the internal water pump, these would be 400k-mile+ engines easily. As for wear, this engine is right in line with expectations for the exposure. Zetec ® was superseded by the Duratec I-4. 2.0L/2.3L/2.5L SOHC ENGINES Ford's first North American metric engine featured a belt-driven overhead cam and finger- follower valve train, while retaining traditional cast iron block and head. The 2.3L SOHC was the base engine of numerous 1974-1997 models, including Mustang, Pinto, Fairmont, Ranger, and UGAYI.

is the 3.5 duratec a good engine