Jeep plans to boost the Wrangler's fuel economy with the introduction of a diesel engine.

A freshening is planned for the Wrangler when the diesel goes on sale.

No word on pricing, but the diesel likely will be costly.

AUBURN HILLS, Michigan — Jeep Wrangler enthusiasts who have been asking for a diesel engine will get their wish in about two years.

The diesel will be available in the 2016 Wrangler, which will debut in 2015.

"The engine will be introduced toward the end of the model's lifecycle to boost sales before they bring in the redesigned model," according to an industry source who asked not to be identified.

At the same time, the 2016 Wrangler will be freshened, possibly with new interior trim and exterior colors.

Automakers sometimes introduce new technology or a new engine to create a buzz for a model that is nearing maturity. In particular, diesel engines are being added by automakers because of rising fuel prices and a government mandate for better fuel economy.

The specifics about the Wrangler's diesel engine are unclear, although it is likely to be the same engine that is optional in the 2013 Ram pickup and 2014 Grand Cherokee.

The Grand Cherokee is available with a turbocharged 3.0-liter Ecodiesel V6 that is mated to an eight-speed automatic transmission. The V6 is produced by VM Motori, an Italian engine maker in which Fiat holds a stake.

The engine produces 240 horsepower and 420 pound-feet of torque. The Grand Cherokee's fuel economy is rated at 21 mpg city and 28 mpg highway for the model and 30 mpg highway for the 4x2. Sales begin this spring.

A diesel engine is a pricey option. Jeep is asking a $4,500 premium for the Grand Cherokee's diesel engine, making it $2,305 more expensive than the Hemi V8.

In addition, depending on the state, the price of diesel per gallon can be considerably higher than gasoline.

The AAA Daily Fuel Gauge Report on Friday pegged the average price for a gallon of diesel fuel at $4.13 versus $3.77 for a gallon of regular unleaded gasoline.

Edmunds says: It no surprise a diesel engine is planned. After all, both consumers and the feds are demanding the same thing — better mpg.