dude with all the money you're gonna put into sourcing a smaller camshaft, ecu, and injectors (btw i believe all injectors are the same size for civics unless you have a B-series engine in your car.) you could use it to fill up your tank. if you run aDX ecu, you'reengine is gonna be running lean. not a good thing. and why would you buy a civic si only to strip it of its performance and make it get the gas mileage of an insight or a hybrid? Original Si's are hard to come by and its something that one should be proud to own. I worked at a dealership among mechanics for awhile and driving TOO slow is just as detrimental to gas mileage as driving excessively fast. I've seen 5.7L Hemi's get 16 and 17 gas mileage! thats about even with my mom's old 3.5L V6 minivan! I'm tellin ya cuz down here shifting at 2000 rpms means driving down the road with your hazard lights on [&:].. i'm with the dude above me... i dont mean to be insulting or offensive, i just find it rather shocking what you wanna do.

 

the guy i got it from was going to junk it!!! thats right, to the bone yard! i said does it run? he says, it runs great! fine i'll take1 i got it free!!! and i must say its the most fun car i've ever owned! don't get me wrong i love to slam it thru the gears to the redline but just the same i want to be burried in this baby! if i can get an ecu for 20 bucks??? and the injectors must be the same(240cc). and i got a cam for free from a guy at work here, would it run just as smooth and run for the next 20 yrs reliably???

 

92-95 vx hb rated at 48 city 55 hway??? the list goes on- the early 90's cx's 42 city 46 hway? if my si can get 40 what could these other cars get? do we really need hybrids?

 

if gas was 10$ a gallon would you slow down then?

 

there you go with your log books again...but seriously, gene is right...he knows his ****...but, gene...are you sure your not thinking about a new civic..he has an eg.

and no....all civic injectors are not the same..lol, your silly, the dx uses a smaller injector than say the EX and duh, the Si.

also..you dont need a smaller cam..but it will keep you from running super lean....im not even sure how lean you would go if you didnt replace it..but since the old civics ran really lean, i would have to say, if you dont change it, then you could blow your motor..but since you got it for free...who cares

i would just leave it...but hey, its your car. if you wana try it..best of luck to you man!

 

The point I was trying to make, was that unless he is already using extreme measures he is not getting 40 MPG, and the only way he will ever get 50 MPG is to replace the entire motor with say,.....the 600cc chain drive motor cycle engine that the very first Civic came with. Just "detuning" the stock engine will only result in a slight increasein mileage.

Unless I see a logbook, I take any mileage claims with a very large grain of salt. It is easy to take a mileage reading on a road trip and see good mileage. It is another to keep a day-to-day record. My average for 12K miles is about 36 MPG, my best tank is 42.5 MPG. When someone asks me my mileage, which figure should I quote?

Example: I asked a friend (female) what mileage she was getting with her Toyota Echo. She said 35 MPG. When I asked her how she knew, she said because the sticker said so. It's hard to argue with that logic..........

Note: the above comments are not aimed at anyone. I am just speaking generally.

 

yea...lol....chain drive motor bike engine FTW!

i know how you and your millage stuff works..... i like that chicks thinking..lol

but yea...i just figure that i get at least 40mpg since i havent ran out of gas and dont have a fuel gauge...i know sometimes i get more...but i also average that back out by shifting at 7k once in a while

i agree..hes not going to get to 50 by swapping injectors with a difference of like 40cc tops...and using a different ECU...he might get MAYBE on average 5 more MPG... thats why i was just agreeing with "just be happy its running good" hell its a free car, i would just leave it alone..

 

This isn't a bad idea ifdrivers and bike insurance aren't too bad in your area. Some places bikes just aren't as practical. Some newer 200-250cc bikes get around 60-70MPG, with some even eclipsing 100MPG. That'd be almost TRIPLE the mileage a lot of people are getting with their Civics, and more than 5x the mileage I get with my Jeep. A lot of the 250cc bikes are highway-capable these days too.My early '80s Kaw 440 often ran 150 high-revving miles on a 3gal tank. A little moped or scooter could easily do better if you don't have to drive faster than 30MPH.