Atop the wish list for many Jeep Wrangler owners is one simple request: build our beloved, go-anywhere SUV with a diesel engine option. Not only would a diesel Wrangler offer up greater fuel economy on road, but it would deliver an extended range off-road, too, presenting a win-win scenario for hardcore off-roaders.

As The Detroit Free Press points out, a diesel Wrangler may soon be a reality, but there’s still one final hurdle to clear. To justify the expansion of Jeep’s diesel product offerings, first the new diesel-powered Grand Cherokee must prove to be a commercial success.

The Grand Cherokee diesel uses a Fiat-sourced 3.0-liter EcoDiesel V-6, rated at 240 horsepower and a stump-pulling 420 pound-feet of torque. On the highway, the diesel version will deliver up to 32 mpg, a gain of 9 mpg over the gasoline-powered 3.6-liter V-6 Grand Cherokee, or 11 mpg better than the current 3.6-liter Jeep Wrangler.

While there’s no doubt that a 30+ mpg Wrangler would have appeal, it’s not clear if buyers would be willing to shell out the additional cost that the diesel engine dictates. That’s why Jeep is using the more expensive Grand Cherokee as a barometer to gauge customer interest in diesels.

If you want a Jeep Wrangler diesel, then, it’s in your best interest to convince all your neighbors to buy Jeep Grand Cherokee diesels, and preferably as soon as they hit dealerships.