I wonder why some people have the same model car and same year but different motor? I have this question because one day i went t a car show and there was a Nissan Silva but one of them had a sr20de engine. But the other one had a sr20det engine. I found out that same model carhave different engines because the driver wants to have more speed in his car. For example the sr20de engine has about 140 - 169 hp and it doesn't have turbo http://en.wikipedia.org/wiki/SR20DE#SR20DE . But the sr20det has turbo http://en.wikipedia.org/wiki/SR20DET.