Every time a car enters a new generation, it runs the risk of gaining weight. Safety equipment, convenience features, and the ever-larger interior demanded by customers all make keeping weight down a problem. The 2015 Ford Mustang is no exception. There's been some speculation that this latest model would weigh significantly more than the outgoing one. A purported "source book/dealer manual" posted to the enthusiast site Mustang6G may provide some answers.

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If it's genuine, the book shows the final curb weights for all 2015 Mustang models. Starting at the bottom, the base 3.7-liter V-6 coupe is said to weigh 3,526 pounds with a manual transmission, and 3,529 pounds with an automatic. The V-6 convertible said to be 3,644 pounds, and 3,654 pounds with an automatic.

So far, the weight gains aren't too significant, but the outgoing Mustang isn't anywhere close to being considered light. If accurate, it means the V-6 coupe adds 25 pounds with the manual, and just six pounds with the automatic compared to the 2014 model. The convertible gains 24 pounds with the manual, and two pounds with the automatic.

The 5.0-liter V-8 2015 Mustang GT coupe is expected to weigh 3,704 pounds with a manual transmission, and 3,727 pounds with an automatic, gaining 86 pounds and 52 pounds, respectively. The convertible is expected to weigh 3,825 pounds with a manual and 3,852 pounds with an automatic, representing gains of 90 pounds and 60 pounds.

Both the base V-6 and GT models use engines that carry over from the 2014 Mustang, but Ford will also launch a Mustang EcoBoost with a new 2.3-liter turbocharged four-cylinder engine for 2015. Base curb weights for that model are said to be 3,517 pounds and 3,512 pounds (manual, automatic) for the coupe and 3,642 pounds and 3,661 pounds for the convertible.

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The 2015 Ford Mustang V-6 coupe will start at $24,425 with a manual transmission. Selecting the EcoBoost four-cylinder bumps the base price to $25,995, while the GT will start at $32,925.

With pricing, equipment, and curb weights revealed, the only missing piece of the 2015 Mustang puzzle is a set of performance specs for its four, six, and eight-cylinder engines.

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