Bill,
It's a 170 hp engine. Here is a clip from the review:
"Just check the dimensions and specs. The Solstice's wheelbase is 6 inches longer than the Miata's but its overall length is less than 2 inches greater. Although it's 5 inches shorter than the S2000, its wheelbase is almost an inch longer. The Solstice is powered by GM's four-cylinder 2.4-liter Ecotec engine that produces 170 horsepower compared to just 140 in the Miata. However, it is 400 pounds heavier than the Miata, closer in weight to the S2000. Honda's S2000 is powered by a 240-horsepower engine, but its torque rating is slightly lower: 161 pounds-feet vs. the Pontiac's 170 pounds-feet. Torque is that force that propels you from intersections and up hills. Consequently, the real-world performance of the Solstice appears to be closer to the S2000's than to the Miata's. We shall see."
The Miata is 140 hp.