Wrangler JL Fuel Efficiency

Wrangler JL Fuel Efficiency, 3.6L, 8 Speed Auto

Fuel efficiency is just one of the many areas of which the JL was improved. This article, and this video, will review the fuel efficiency of a 2018 Wrangler JL Sahara Unlimited, with the 3.6L Pentastar engine and the 8 speed automatic transmission. Aerodynamic, the use of weight saving materials, engine and transmission improvements can mostly be attributed to improved fuel efficiency results. 

Aerodynamic Improvements

Albeit slight, there are some improvements in the JL’s aerodynamic design that contribute to improved fuel efficiency results.  

Front Grill & Hood

The front grill has an increased rake halfway up the grill, and a bulge on the hood. At a glance, these barely noticeable alterations to the front end design contribute to a rounding of the front end of the Jeep Wrangler JL.  This more aerodynamic front end shape was absent in the previous Jeep Wrangler JK design. 

Front Windshield Angle

The rake, or recline angle of the front windshield of the Wrangler JL was also increased. In comparison to the more vertical windshield of the Wrangler JK, the Wrangler JL would be more aerodynamically efficient with this increased rake angle.

The Use of Lighter Materials

For the first time in the Jeep Wrangler lineup, aluminum hood, fenders, doors, and tailgate panels were used.  Among other items made with aluminum,the intent of increased use of light-weight aluminum in the construction of the JL was to aid in the improvement in fuel efficiency.

Transmission Improvements

For the first time in the Jeep Wrangler line up, a ZF eight speed automatic transmission was offered, with the intention of improving ride performance, as well as improving fuel efficiency. 

Engine Improvements

In 2018 Jeep had released a smaller 2L Turbo engine to provide more fuel efficiency, but changes to the existing 3.6L Pentastar were also made in an effort to improve fuel efficiency over the previous 3.6L in the Wrangler JK. The highlights of these changes are featured in the graphic below, and can be studied further at this forum.

Real Life Jeep Wrangler JL Fuel Efficiency Results

However, can all of the above changes in aerodynamic design, use of weight saving materials, engine and transmission improvements result in significant improvement in fuel efficiency results? The results below show samples of real life outcomes from weekend trip up north.  The type of driving essentially consists of some driving through towns, but mostly highway driving on secondary highways and super highways with speeds ranging between 80 to 100 kms per hour.

The graphic below highlights some impressive fuel efficiency numbers experienced in my 2018 Jeep Wrangler JL Sahara with the 3.6L Pentastar engine. The results are in L/100 kms, mpg(Imp), and mpg(US).

In an effort to take a more scientific approach, I filled my tank, drove my weekend trip up north and back for the weekend, and recorded my milage and fuel consumption to hand calculate my fuel efficiency. The graphic below illustrates my hand calculated results.

Essentially, I did a 646.7 km trip up north and back and averaged 31 mpg(Imp), 26 mpg(US).

When I compare my hand calculated results to the trip computer, they are fairly consistent.

The 2018 Jeep Wrangler JL fuel efficiency is very impressive in comparison to posted Jeep Wrangler JK fuel efficiency results


Thus, it would appear that the aerodynamic improvements, the use of weight saving materials, engine and transmission improvements made to the Wrangler JL, have resulted in improved fuel efficiency, as observed by this author.