Mercedes-Benz has long been a supporter of diesel options in its growing line of SUVs, but there looks to be a mild shake-up happening for the 2015 M-Class.

The long-serving 3.0-liter V6 turbodiesel won’t be answering the bell, replaced instead by the 2.1-liter four-cylinder found in the smaller GLK and mid-sized E-Class sedan. So the new ML250 BlueTEC will pack 200 horsepower and 362 pounds-feet of torque versus the old ML350 BlueTEC’s 240 horses and 455 pounds-feet.

AutoGuide quotes company product manager Joseph Stauble, who said the choice had more to do with customer demand “for a more efficient diesel” rather than improving its CAFE scores. But we don’t know why they wouldn’t continue to offer the V6 diesel and add the four-cylinder to cover all their bases otherwise.

While the 2015 ML250 BlueTEC will carry an MSRP of $50,725 — a mere $1,000 drop — and the EPA-estimated fuel-economy figures will almost certainly improve, how it performs in the real world will be the biggest question.

SEE ALSO: 2014 Mercedes-Benz E250 BlueTEC 4MATIC Review

What AutoGuide hasn’t mentioned relates to its non-diesel models: the twin-turbo V8 ML550 with 429 horsepower and a stout 516 pounds-feet of torque has been dropped in favor of a new twin-turbocharged V6. The resulting 2015 ML400 will offer 329 horsepower and 354 pounds-feet of torque.

Once more hard details about pricing, availability and fuel consumption are confirmed, hopefully by late October, the situation should become clearer.