A Closer Look at the 4 Jeep Grand Cherokee Engine Options
The Jeep Grand Cherokee lineup is big and strong as it offers consumers plenty of choices ranging from advanced off-road capabilities to luxury to tons of power. There are four different engine options on the Grand Cherokee lineup and each of them is very different and has unique performance qualities. Here’s a closer look at all four engines.
3.6L Pentastar V6 Engine
The 3.6-liter Pentastar V6 engine is the standard engine on the Jeep Grand Cherokee lineup and it is a great engine that balances power, fuel economy and towing capacity.
The 3.6L Pentastar engine has a dual overhead camshaft (DOHC), which is it’s a valvetrain configuration that is known for performance and efficiency. Due to the placement and use of two camshafts (one to lift the intake valves and one to lift the exhaust valves), engines with a DOHC valve train are known to be efficient and produce a substantial amount of power.
The engine produces 295 horsepower and 260 lb-ft of torque and has a maximum towing capacity of 6,200 pounds. When equipped with this engine, the Grand Cherokee has a fuel economy of 19 mpg in the city, 26 mpg on the highway and 21 mpg combined.
5.7L HEMI V8 Engine
A step up from the 3.6L Pentastar engine is the 5.7-liter HEMI V8 engine. In addition to having more cylinders and larger displacement, this engine has a couple different designs, like HEMIs and VVT, that help it to increase power.
HEMI refers to the engine’s unique hemispherical combustion chambers in the cylinder and their design decrease heat loss and creates more room for valves. VVT stands for variable valve timing and it is a relatively new technology that alters the timing of valve lifts. VVT helps to improve fuel economy, power and emissions.
The 5.7L HEMI engine pushes out 360 horsepower, 390 lb-ft of torque and gives the Grand Cherokee a maximum towing capacity of 7,200 to 7,400 pounds.
3.0L EcoDiesel V6 Engine
Much different than the three other engines on the Grand Cherokee lineup is the 3.0-liter EcoDiesel V6 engine. Due to the different qualities of diesel fuel, diesel engines often produce more torque, have higher towing capacities and increased fuel efficiency in comparison to gasoline engines of the same size.
Diesel fuel requires a much higher temperature to ignite and burn, so diesel engines need to have a much higher compression and their fuel burns more efficiently. One way to achieve higher compression is with a bore-stroke ratio that is undersquare or less than 1:1, meaning the bore is smaller than the stroke. In addition to an increase in compression ratio, undersquare engines produce more torque than square over oversquare engines.
For instance, the compression rate of the 3.0L engine is 16.5:1 and the bore-stroke is 3.27×3.60, which is a bore-stroke ratio of .9:1. However, the compression rate of the 5.7L engine is 10.5:1 and the bore-stroke is 3.92×3.58, which is a bore-stroke ratio of 1.09:1.
All of that explains why the much smaller EcoDiesel engine produces more torque and has the same towing capacity (7,200 to 7,400 pounds) as the 5.7L V8 engine. Additionally, the EcoDiesel engine has the best fuel economy of all of the engines, which is 22 mpg in the city, 30 mpg on the highway and 25 mpg combined.
6.4L SRT HEMI V8 Engine
Then finally, there is the performance engine, the 6.4-liter SRT HEMI V8 engine that is only available on the Jeep Grand Cherokee SRT. This engine produces 475 horsepower and 470 lb-ft of torque and it is the fastest engine in its class.
Short for “Street and Racing Technology,” SRT is a group of engineers within Dodge that are focused on creating performance engines and parts. This engine is the same performance engine that is available on the Dodge Charger and Dodge Challenger lineup.
This engine is the biggest engine, it has HEMI combustion chambers and it is an oversquare engine, which means the bore is bigger than the stroke. While a smaller bore-stroke ratio produces more torque, a larger bore-stroke produces more horsepower. With a larger bore, more intake and exhaust valves can fit in the cylinder, so air travels better and produces a larger combustion and more power.
Want to check out all of these engines for yourself?
Come test drive all of them at Hollywood Chrysler Jeep and you can view our Jeep inventory here.