At the beginning of 2013, Mazda and Alfa Romeo signed an agreement that will bring a new roadster to each company: a new MX-5 for the Japanese company->ke53 and a new Spider for the Italian one->ke1386. Both models will be built at Mazda’s Hiroshima plant starting 2015, but each model will offer its own engines.

Until now, it has been rumored that the MX-5 would use a 1.3-liter turbocharged engine that features SkyActiv technology. However, new details suggest that the tiny roadster could also get a diesel engine. you read that right; we said diesel…

However, because a diesel roadster could be a tough sell to traditionalists, Mazda will still offer a gasoline alternative. Rumors suggest that this diesel engine will be a naturally aspirated 1.6-liter SkyActiv engine that produces approximately 130 horsepower. This would give the Miata its lowest horsepower output since it bumped the standard 1.8-liter four-cylinder to 133 horsepower in 1996.

As for the Spider version, it could be offered with a turbocharged 1.4-liter ‘TB’ engine with power ranging from 120 horsepower in the base model to 296 horsepower for the top versions. Both models will be offered with a six-speed manual gearbox.

Mazda will focus on offering modern materials and design techniques that could help keep the total weight down to about 1,760 pounds.

Click past the jump to read more about the next MX-5.

About the next Mazda MX-5

The MX-5 initially arrived on the market in 1989 and since then it has become one of the best sold roadsters on the market. It saw three different generations, numerous design updates and a handful engine changes. The fourth generation is set to be unveiled sometime at the end of 2014.

Rumors suggest that the MX-5 will remain a rear-wheel drive compact sports coupe with exterior design inspired by the Shinari Concept we saw back in 2010.

As for the engines to be found under the hood, we have heard all kinds of rumors, starting with a 1.3-liter turbocharged 4-cylinder with an output of 200 horsepower and up to a 2.0-liter engine that produces north of 145 horsepower.

When put on sale, the MX-5 will be priced a little under $30k.