The DX, LS, EX all have the SOHC I4 1.8liter engine with 140horses @ 6300rpm and 128lb-ft torque at 4300 rpm.

The Si will have the DOHC I4 2.0liter engine with 197horses at 7800rpm and 139lb-ft of torque at 6200rpm. This is the same as the RSX but 20 horses less at the same rpm.

The hybrid will have the SOHC I4 1.3liter engine with 110horses @ 6000rpm and 123 lb-ft of torque at 1000 rpm (probably has more torque at low speeds in electric mode).

The 2-door coupe weighs more than the 4-door sedan by about 150lbs.

Specs are here. (auto.consumerguide.com).