Detroit Diesel officials say that the $1.5 billion they spent developing the new DD-15 heavy truck engine is the most that’s ever been spent to bring a new engine on-line.

In a press release, company officials said the DD-15 displaces 14.8 liters with a six-cylinder, inline design.

The company unveiled the engine Friday, Oct. 19, but the market launch will come next spring when it’s introduced in the Freightliner Cascadia.

Company officials said the DD-15 meets ’07 emission standards and can be easily modified to meet 2010 standards.