Civic HX has VTEC-E (efficiency) this is not a performance engine
Civic EX has SOHC VTEC rated @ 130hp
Civic Si has DOHC VTEC (the good kind) @ 160hp

Integra GSR has DOHC VTEC @ 170hp... The kick in the pants around 6000 rpm is well worth the extra cost.

by the way, the NSX was the first VTEC equipped car, not the Civic.
I believe it went NSX- Prelude- Civic Si...

Phil