The QR25DE is a 2.5 L (2,488 cc) variant built with cast steel connecting rods, a steel timing chain, counter-rotating balance shafts, and an aluminum intake manifold. The engine bore and stroke is 89 mm × 100 mm (3.50 in × 3.94 in) and a compression ratio ranging from 9.5:1 to 10.5:1 depending on the vehicle.
The QR25 engine is a part of Nissan’s QR family of inline-four piston engines that were introduced in 2000. They have a DOHC (dual overhead camshaft) design wih four valves and variable valve timing. The QR25DE is a 2.5 liter variant that’s built with cast steel connecting rods, an aluminum intake manifold, counter-rotating balance shafts and a steel timing chain. The output is anywhere from 152 horsepower (2005+ Nissan Frontier) to 170 horsepower (PZEV-compliant Altima) and 175 horsepower (Altima 2.5 and Sentra SE-R).
In 2007, there was a revision on the QR25DE engine, which improved on a lot of things and resulted in a higher rev limit and a better power output. The QR25 engine for sale is popular with people who want to replace their engines or do an engine swap with the QR25 or QR20 engines.