So I wanted to get more MPG, I have an AT 93 Civic DX HB with a D16z6 swap in it. When I drive between 45 and 5 MPH I get around 38-40 MPG. But I live 70 miles away so you see I have a need to travel bit faster. I wanted to to do a manual conversion from AT to Mt and slap a JDM D15z1 in my HB. I have the harness, and the fed ECU and EGR box. But I came across a d15z1 AT engine, I did some research and seem like it was released only outside the USA. My question is anyone have any MPG out of this engine and tranny combo? What ECU does it use? Any info would be greatly appreciated. Thanks.
Doing an engine and transmission swap can get complicated, especially with something like the Civic VX. Believe it or not, most of the fuel economy gains are from the transmission gearing. If you could successfully swap from an automatic to a manual transmission, then you'll have achieved most of the gains you're looking for. Auto to manual swap is no walk in the park and while I don't know the specifics of the 92-95 civics, I do know on the 96-00, there are some sensors or actuators used that have more or less wires between the manual and automatics. I.e the idle air control valve may have 3 wires or 2 wires depending on the engine and if it comes with an auto or manual transmission. This means you'll possibly need to swap harnesses and the ECUs and other intake manifold related parts to make sure the car runs optimally and passes smog. If you have a copy of the helms manual along with the electrical wiring diagram, with enough time and patience, I'd imagine you can successfully do this swap. The thing that annoys me about this swap the most is that you have to cut into the body panels in the interior, then patch up the old hole so that you'll be able to link up the manual shifter. Also getting all the miscellaneous parts to make the car work as a stick shift seems like a tedious task.
As for your D15Z1 AT, I'm not familiar with that animal ever existing but stranger things have happened so I won't discount it as being possible. Link perhaps? Maybe your best bet is to just get that magical transmission, though you'll want to confirm its gear ratios so that you ensure you're actually getting a significantly taller geared transmission.
This is the link to the engine i am looking at, funny thing is they have it listed at 125hp, when here in the USA its 92hp. I have not found any other info to verify if indeed the ETi or JDM AT was indeed 125hp.