In terms of sport trucks, I recently did a shootout with four available trucks in Gran Turismo, so the Chevy SS Concept is not included. The deciding factors was Sports Soft tires, and I was racing El Capitan. Here are the results:
1 - Ford SVT Lightning 2:07.537
2 - Toyota Tacoma X-Runner 2:08.802
3 - Chevrolet SSR 2:12.492
4 - Dodge Ram Laramie... 2:14.???
The Dodge Ram result that I had... I accidentally deleted it from the Standings during my Arcade Mode test, so that's why I approximated the results. The only modification I made in Arcade Mode was that they all had Sports Soft tires. This is assuming that all machines are unmodified. I got a lot of respect for the Dodge Ram. It's such a mean-looking truck that means business. It may have been a better call to have the SRT-10 Ram rather than the Hemi (still good). The Ram just felt too heavy on the smooth-flowing El Capitan track. The SSR seemed more powerful and agile. Since it's a convertible, I believe you can race it in the Spider and Roadster race series. The Tacoma X-Runner was very agile. It's power could have been increased to maybe 270 or even 300, then this thing would be a sports car. Yeah, I'm not calling it a truck. It's very car like. The SVT Lightning had some good performance for a machine that I once thought was for the 1/4 mile. So based on this, I'd pick the Lightning if you're in this series.