Click above for a high-res image gallery of GMC Terrain spy shots

In what may be the first recorded instance of an embargo break in Twitter's short but influential history, General Motors has mistakenly Tweeted a few salient details about the upcoming GMC Terrain, the embargo of which won't be up until April 5, 2009. Regardless of how the information got out there, the important bit is that the 2010 GMC Terrain will seat 5 adults and deliver 30 miles per gallon on the highway, and that's pretty good mileage for a midsize crossover that can seat your entire brood.

We can't say what powertrain is able to manage that figure, but a quick check of the Terrain's competition reveals that the only vehicles that beat 30 mpg on the highway are the Ford Escape Hybrid and Saturn Vue Hybrid. Interested in knowing more? Hang tight, we're sitting on all the rest of the details and we'll be ready to share on April 5th.

Related GalleryGMC Terrain - spy shots

[Source: GM via Twitter via Jalopnik]