How Can I Improve Gas Mileage In My Jeep Grand Cherokee?

By Nick Marchenko, PhD

Updated: August 30, 2023

Why is your Jeep mpg so low? Despite the emergence of hybrid and electric vehicles, many car owners still prefer to drive a Jeep Grand Cherokee with engines powered by gasoline or diesel. This choice is due to their simplicity and convenience compared to hybrid or electric vehicles.

Nevertheless, almost every driver, at least once or several times, faced the need to reduce the fuel consumption of his Jeep Grand Cherokee. This complex and individual moment depends on certain factors, such as the weather and the vehicle's condition.

Motorists seek to reduce Jeep Grand Cherokee fuel consumption for several reasons: increasing mileage on one fuel tank, saving money, and improving driving distance.

The following article will describe the main reasons for increased fuel consumption and how to save on fuel mileage.

Key Takeaways:

• The fuel consumption of diesel engines is 20-30% less than gasoline engines, with diesel fuel being denser and more efficient.
• For optimal fuel efficiency in the Jeep Grand Cherokee, it's essential to maintain recommended cruising speeds, use cruise control, and enable ECO-Mode.
• Ensuring that the Jeep Grand Cherokee is in good condition, particularly regarding spark plugs, filters, oil, and overall engine components, can significantly reduce excessive fuel consumption.
• Modern Jeep Grand Cherokees equipped with various sensors can provide detailed information on system malfunctions that may result in fuel overconsumption.

Which Jeep Grand Cherokee has engines with the best mileage?

Many factors affect the fuel consumption of the Grand Cherokee. These are the structure of the engine itself, the number of cylinders, and the number of valves. There is an opinion that the larger the volume of the engine, the greater its fuel consumption. But such a statement is not entirely true.

The lowest fuel consumption is achieved either with small engines or larger ones. Small motors (up to 1 liter - up to 1.2 liters) benefit from a small volume - they have few cylinders and burn little fuel per stroke. Because of this, they have pleasantly low fuel consumption.

In contrast to them, large engines can also have lower fuel consumption. The more powerful the engine, the easier it is to move the car from its place; accordingly, less energy and fuel are used.

On the other hand, larger Jeep Grand Cherokee engines can also offer good fuel efficiency. When the engine is more powerful, it can easily move the car from a standstill, using less energy and fuel. While this method is not widely applicable and relevant, installing powerful engines on lightweight vehicles can improve fuel efficiency.

Are diesel or gasoline engines more fuel-efficient?

The fuel consumption of diesel engines is much lower than that of their gasoline counterparts; diesel engines use 20-30% less fuel.

Moreover, diesel engines have greater efficiency and traction: they are better suited for towing and load transportation.

Also, diesel engines have more torque and work better at low revs. However, everything has side effects. Jeep’s gasoline engines are more powerful, accelerate faster, and have better dynamics.

Finally, the efficiency of diesel engines is determined by the properties of the fuel itself. It has a higher combustion efficiency. Diesel fuel is denser than gasoline; on average, it gives off 15% more energy when burned.

Diesel, unlike gasoline (which requires a ratio of 11:1 to 18:1 with air), burns in almost any ratio with air. The diesel engine injects as much fuel as is necessary to overcome the friction forces of the cylinder-piston group, the crankshaft, and the oil pump.

In practice, this leads to a decrease in fuel consumption at idle by 2–3 times compared to gasoline. Burning with air compression also explains the weak heating of diesel engines during operation. Diesel is always less thermally loaded, which means it`s more resourceful and has more torque.

Therefore, you need to decide what is more important to you:

• If you need to drive fast and don't often carry loads, choose a gasoline Jeep Grand Cherokee;
• A diesel Grand Cherokee model is your choice if you require low fuel consumption and better traction.

How to increase the fuel mileage of the Jeep Grand Cherokee?

Reducing fuel consumption depends on many factors and can have good and bad effects, depending on the conditions and model year of your Jeep Grand Cherokee.

We will give only general methods - strive to follow them, and you`ll be pleasantly surprised by the decreased fuel consumption of your Jeep.

Keep the speed limit

If you often accelerate or drive at high speed, then don`t be surprised by the increased fuel consumption of your Jeep Grand Cherokee.

When the engine is running at high speeds, it consumes more fuel. However, driving at a speed of 20 miles per hour won`t help you reduce mileage either.

So, how do you choose the optimal speed for driving? Well, each Grand Cherokee model year has a recommended so-called cruising speed.

By following it, the engine will consume the minimum amount of fuel. Cruising speed is usually indicated on the dashboard of your Jeep Grand Cherokee, and sometimes it is even duplicated on the dashboard of the car.

Use cruise control

If your Grand Cherokee is equipped with a cruise control system, use it on long road trips. The vehicle will independently “adjust” the amount of fuel entering the cylinders. The fewer uneven or different presses on the accelerator pedal, the better the fuel consumption will be.

Enable ECO-Mode

If your Jeep Grand Cherokee model has an eco mode, turn it on. In this way, the vehicle automatically sets all necessary parameters and turns off all unnecessary systems, which leads to low fuel consumption and increased environmental friendliness.

Avoid sudden/sharp acceleration

When you sharply press the gas pedal, the Jeep Grand Cherokee consumes a lot of fuel. Strive to avoid sudden/sharp starts, but press the gas pedal slowly and smoothly.

Imagine you have a cup of coffee on the dashboard and accelerate so as not to spill it.

Avoid frequent idling

Despite low revs, any Jeep Grand Cherokee uses quite a lot of fuel at idle. An average car with a 3-liter engine uses 300 milliliters (more than 1 cup) of fuel every 10 minutes of idling. Try not to let the car idle for too long. If you understand that long downtime awaits you, it is better to turn off the engine.

Do not turn off Jeep Grand Cherokee in traffic jams or at every traffic light

There is an opinion that if you turn off the engine at each traffic light and start it again when it's time to move, you`ll save some fuel.

It`s just a myth. You will only get significant fuel savings if you stand in a traffic jam in one place for 30 minutes), but rather the opposite - when starting, the Grand Cherokee uses more fuel than when it is idle.

In addition, constant turning off and starting the engine leads to faster starter wear.

Assess the situation on the spot - if you understand that you must stand still for five or even more minutes, it is better to switch off the car. But if you understand you are moving a little, you should leave the engine on.

Remove excess cargo from your Jeep Grand Cherokee 

Undoubtedly, there are times when the car needs to be filled almost to capacity, especially during long trips. Then there is no fuel economy to speak of.

Since the distance you cover during the day is insignificant, avoid putting extra cargo in or on the Jeep Grand Cherokee. Everything you don't need but that takes up space in the car, like bags, tools, and some personal stuff, increases its weight.

As a result, it requires more energy for movement, and fuel consumption increases. Unload the trunk, remove the railings from the roof (if any), minimize the weight of the Jeep, and then fuel consumption will be lower.

Keep an eye on the tire pressure

Poorly inflated tires are an important aspect everyone ignores for some reason. Tires with low pressure have more rolling resistance on the road.

That means that your tires create more friction and rolling resistance with every mile you travel, leading to increased fuel consumption. If all your tires are 10 psi underinflated, your Jeep Grand Cherokee fuel consumption can increase by 10%.

Use the air conditioner wisely

The air conditioner takes away engine power and increases fuel consumption. Keep that in mind. We're not telling you to drive without AC and suffer in the heat to save a gallon of fuel - you don't have to make such sacrifices.

However, if the Jeep Grand Cherokee has already cooled down enough, you can turn off the AC for a particular time - this will allow you to reduce fuel consumption slightly. And when the temperature starts to rise, turn it back on.

Turn off power consumers

This method is more relevant for emergencies, when there is an extremely low amount of fuel left, and you must somehow get to the nearest gas station. Turn off everything that needs energy - lights, heaters, AC, and other electrical appliances.

This will help you take some load off the Jeep’s engine and get to the gas station. Don't abuse this method, especially when it gets dark. It is better not to go to such desperate measures as turning off the headlights at night.

Monitor the condition of your Grand Cherokee 

Indeed, one of the ways to achieve normal fuel consumption is to keep the Jeep Grand Cherokee in perfect, or at least good, condition. If the car is in good condition, it will consume less fuel. Here are a few things to pay attention to.

Spark plugs

When spark plugs fail, they can harm the engine's overall performance. If they don't produce a spark or a weak one, the fuel doesn't ignite properly, leading to misfires and reduced power. This inefficiency causes fuel waste and increased consumption.

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Filters

Filters play far from the last role in the proper engine operation. When filters become clogged, this leads to a deterioration of their permeability.

As a result, it becomes more difficult for the engine to gain power, and because of this, fuel consumption increases. Remember to change your Jeep Grand Cherokee's fuel and air filter on time - this is the key to the long and reliable operation of the power unit.

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Oil

Oil replacement should always be addressed. When all engine elements are lubricated and work as they should, fuel consumption drops significantly. When something prevents the engine from working, more energy is wasted, and fuel consumption increases.

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Overall condition of engine components

Over time, engine components wear out - this is a common and usual process. And this has many consequences. Power is lost, the strength of parts decreases, and breakdowns occur more often. 

It becomes more difficult for the engine to perform its main functions, so fuel consumption increases. If you notice that the fuel consumption of your Jeep Grand Cherokee has increased significantly for no apparent reason, even though you followed all the previous points and recommendations in this article, critical wear of any elements may have been reached.

Here are examples of such wear:

• Сylinder-piston group wear. Burrs in the cylinders burned pistons, and deposits in the combustion chamber complicate the engine's operation. As a result, more fuel is consumed during engine operation;
• Valve wear. The most frequent problem with valves is the loss of their tightness. If the gap between the valve and its seat increases, this leads to more fuel entering the combustion chambers, and, as a result, the fuel consumption increases while not giving more power. This can lead to leaks and cracks in the valves, as well as grinding during operation;
• Wear root liners and crankshaft backlash. The crankshaft of the Jeep shouldn't move in one direction or the other - it should sit firmly in place. If it begins sliding from side to side, it leads to energy loss and excessive fuel consumption.

Too rich mixture

Fuel and air form a fuel-air mixture, making the engine work. The amounts of these two ingredients are perfectly measured and must remain in the correct proportions. When there is too little fuel, this mixture is called lean, if there is a lot of fuel, then the mixture is rich. 

This is not good for the engine and leads to excessive fuel consumption. If you hear that the engine of the Jeep Grand Cherokee seems to choke, especially when you press the accelerator pedal, and you see that the fuel consumption has increased and black smoke pours from the exhaust pipe - it means that there is too much fuel. 

This can be due to many factors: pump malfunction, ECU problem, injector malfunction - leakage, breakdown, etc.

Does the Grand Cherokee show any signs of error?

Modern Jeep Grand Cherokee models are very informative thanks to various built-in sensors - they can indicate almost any malfunction in the system.

Look at the dashboard - are there any warning lights, such as the Check engine, or else? 

Connect to the car using the OBD-2 appliance.

If there are any falses/issues, it can lead to overspending. The most common reason for this is the malfunction of certain sensors. They transmit incorrect data to the ECU, and the "brains" of the Jeep Grand Cherokee adjust the fuel-air mixture incorrectly - hence fuel overconsumption.

Install a performance programmer in your Grand Cherokee.

Modern vehicles are equipped with smart electronics that monitor and track any changes or deviations from the system. However, you can prove you are smarter and adjust yourself.

This is done with the help of a programmer - a small unit that plugs into the OBD-2 connector - and allows you to hack into the engine management system yourself.

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Connect this programmer to your smartphone - and set the parameters you need.

In the same way, you can change the parameter to reduce Grand Cherokee’s fuel consumption. This will happen since the engine's power will be reduced by software - and, as a result, it will consume less fuel.

Conclusion

As you can see, there are a lot of different approaches to increasing your Jeep`s fuel mileage. Some may depend on the overall condition of the engine and its components, while others require careful treatment and attention.