Tomorrow is a big day. After months of rumors and renderings we'll have our first official look at the all-new 2015 Mazda MX-5. The fourth-generation model will be a return to the original car's lightweight roots while also retaining the elements that make it an MX-5: front-engined and rear-wheel-drive. But what else will we likely see tomorrow? Good question. Here's what we know: exterior styling could be a blend of the current Kobo design language and the first-gen MX-5's oval styling, most notably the front grille.

Based on a recent spy image, the roadster appears to have a taller rear deck, shortened front and rear overhangs, and muscular fenders. In terms of architecture, 50:50 weight distribution is very likely and total weight will only be around 2,200 lbs. But what's under the hood is perhaps the biggest unknown. We've heard that it could be the 2.0-liter SkyActiv four-cylinder with close to 200 horsepower. The latest rumor is that Mazda has opted for the 1.5-liter naturally aspirated four from the new Mazda2. What's possible is that the latter engine will only be offered in overseas markets. The 2.0-liter mill may end up being the sole engine for the US. So what's the good word going to be? Tune in tomorrow to find out.