Chris Woodyard

USA TODAY

There are some cars that are difficult to mess with without risking alienating those who make up their core group of buyers and biggest fans. Now Jeep looks ready to touch the third rail when it comes to the vehicle that represents the purest form of the brand, Wrangler.

Wrangler remains one of the toughest and smallest rock-crawling SUVs on the market. But it burns a lot of gas.

To improve gas mileage when the new one hits in 2017, Jeep is considering a lighter body, more transmission gears or a smaller engine, according to Automotive News.

The current Wrangler is rated at 17 miles per gallon in the city, 21 mpg on the highway, for either the automatic transmission or the manual. The four-door version gets slightly less.

Wrangler is running into the problem that has bedeviled other models. On one hand, it has to be true to its heritage. On the other, it has to fend off imitators that may win hearts of buyers even if they aren't as capable where it counts. In this case, it's on the trail.

Ford has also tried to handle the same issue with its new Mustang. It broke some of the traditions that have defined the brand in the name of progress and better fuel economy for the 2015 version, which is yet to hit to the streets. (The new one will offer independent rear suspension and a turbocharged EcoBoost engine option, for instance.)

Wrangler also to contend with tougher fuel-economy standards. The News says it could get an eight-speed automatic transmission, instead of the current five speeds. It also could get a smaller engine than it current 3.6-liter V-6, which is a lot of power for a relatively small vehicle.

Aluminum body? Fiat Chrysler Automobiles CEO Sergio Marchionne has hinted at the possibility, but it's not a sure bet.