well if it is indeed a dodge ram van with a v6 than the hp to weight ratio would be 1:26(1 hp to every 26lbs...175hp/4577lbs curb weight) and as far as the dodge caravan we'll just say its the 3.0 v6 since you said it has a 3 speed auto which the 3liter is the only v6 with that option then the hp to weight ratio would be 1:19 and its hard to say what the hp/weight ratio would be unless you give a specific year and trim of crx...but for example a 1989 honda crx si weighs 2174 and has 108hp so it would have a hp/weight of 1:20 which sadly isnt even as good as the caravan but for arguments sake you cant just go by power to wight ratio because there are many factors...tranny ratio...differential ratio and others none of the CRX's are "fast" from the factory by most tuners standards...but once again peoples perception of fast is diff. many people think civic si's are "fast" but not most tuners....fast enough for stock but not fast enough for most motor enthusiast thus thats why there is such a large aftermarket support for cars