Bore: 87.5mm
Stroke: 104.0mm
Compressoin Ratio: 9.1:1
Oil Filter: Full Flow Spin On
Cooling System Pressure:110 kPa, 16 Psi (Same as on 2.2)
Thermostat:195 F (90 C)
Spark Plug Gap:0.09mm (.035")
Spark Plug: RN 12 YC
Firing Order: 1-3-4-2
The 2.5 liter engine was the last gasp of the slant six era of engine design. With its long stroke, single fuel injector, and low performance - high durability design, the 2.5 provided better low end power and more torque than most competitive engines. It was also larger than most engines with similar power outputs. A 2.2 liter engine with a longer stroke and balance shafts, the 2.5 was only available with fuel injection. It was smoother and quieter than the 2.2, and had more power at the bottom end. However, with its long stroke and balance shafts, it was not well suited to high performance applications. The 2.5 turbo engine was not supported for long. The design of the 2.5 may have been influenced by the Mitsubishi 2.6, which also used balance shafts.
The following information is from the 2.5 as it stood in the 1995 Dodge Spirit. It was similar through its life, with some notable changes to help sealing and emissions. The 2.5, its fuel system, and its intake/exhaust system were close to identical in every vehicle it was in: the Shadow/Sundance, Daytona, Dakota, Caravan/Voyager, Spirit/Acclaim, etc.
| Displacement | 153 in3 (2500 cm3) |
| Bore x Stroke | 3.44 x 4.09 (87.5 x 104) |
| Valve System | SOHC, 8 valves, roller followers, hydraulic lifters |
| Fuel injection | Throttle body, electronic |
| Construction | Cast iron block, aluminum alloy heads, counter- rotating balance shafts |
| Compression Ratio | 8.9:1 |
| Power (SAE net) | 100 bhp @ 4800 rpm |
| Torque (SAE net) | 135 lb-ft @ 2800 rpm |
| BHP/Liter | 40 |
| Max. Engine Speed | 5950 rpm |
| Fuel Requirement | Unleaded regular, 87 octane |
| Oil Capacity | 4 qt. (3.8L) |
| Coolant Capacity | 9.0 qt. (8.5L) |
| Emission Controls | 3-way catalyst, heated O2 sensor, engine modifications, EGR |
| EPA Fuel Economy (mpg city/hwy) | 27/33 (In a 1993 Sundance 5-speed) |