The 2015 Ford F-150 represents a new design year for the truck, but largely the vehicles outward appearance remains unchanged. You get a big mean grille, some dressed up new headlights, and a very nicely dressed and comfortable cabin. While all that is great, this year, the really big new lays just below the paint.

Ford has made a big move and is replacing tried-and-true, rough-and-tumble, American-as-it-gets steel with aluminum. It’s not a hugely surprising move for Ford to choose aluminum, it’s a great environmental choice, what’s surprising is that they decide to make the move with their flagship vehicle. A aluminum-bodied Mustang or Focus ST is a safe starting place. The F-150 is Ford’s bread-and-butter, not just Ford’s bestselling truck, not just Ford’s bestselling vehicle, but the bestselling truck in the world 32 years running. Ford moved some 700,000 examples of its F-Series truck in 2012.

The last time Ford took on aluminum they did so with the Mercury Sable. They made a handful in 1993 conceptually, but never sold a single one. Now 20 years later they’ve laid all the cards on the table and are going all in with an all aluminum bodied F-150. Just about every surface of the truck is made of the stuff. The hood, the doors, the side panels, the truck bed, tailgate, all of it aluminum. They’ve even used aluminum in the interior, engine build and suspension. All totaled they’ve pulled 700 pounds off the truck, which is a truly remarkable amount of weight in an industry where every vehicle seems to be adding poundage year after year not losing it.

So why didn’t they go all aluminum 20 years ago? Probably because the stuff is less malleable than steel, thus harder to work with, thus more expensive to manufacturer vehicles with. Working with aluminum doesn’t require a simple materials change at the factory, it requires an almost complete re-tool and thousands of engineer hours. All that time and re-tooling costs billions and it’s all in the name of fuel economy.

So what’s all that weight savings equate to in the new F-150? A class-leading mpg of nearly 30 mpg highway. Insane numbers for a full-sized truck. On top of that aluminum gets you corrosion-resistance, strength and dent-resistance. So while the 2.7-liter EcoBoost V6 may receive ridicule from the “there’s no replacement for displacement” crew you can rest assured that you’re not wasting gas in an oversized V8 to make up for your trucks oversized waistline.