Hi I drive a 1989 honda civic sohc dmfi 1.5 engine with a 4 speed manual tranny, my question is , can I put a 5 speed manual tranny ,and if so wish tranny will be comparable. I don’t know much about hondas so any help will be appreciate

 

yea, use a transmission from a 92-95 civic
you'll need to convert your car to hydraulic clutch also

 

does the 92-95 years came with a hidralic clutch ,if not wish year came hidralic,and do i have to do any modification.

 

yea 92-00 civics have hydraulic clutches.
if you currently have a hydro clutch it'll be a direct swap. if you currently have a cable clutch, you'll have to run the hydro lines and stuff when you install the new tranny

 

will the tranny bolt right in without any modification and the reason of me doing this is that when I’m driving in the hayway when I’m in 4th gear it feels like is asking for a 5th gear, and I’m also looking for better gas millage.know through your experience is this swap worthed, will it give me what I’m looking for thanks in advance you guys rock.

 

i know that it will bolt onto the engine no problem, and it should use the same exact mounts as the old transmission.
like i said before, if you have a cable clutch currently, you will need to convert your car to hydraulic clutch (by installing master cylinder, running fluid lines, etc.) to accommodate for the hydraulic clutch found on the 92-00 civic transmissions.
If you already have a cable clutch, don't worry about that as it should be a direct swap, with no changes needed.

i have no personal experience in whether this swap is worth it or not, but i do know that it will certainly be nicer to have 5 gears instead of 4.
I am unsure of whether you will get better gas mileage or not, because typically the longer your gears are, the better the gas mileage. I am pretty sure the gears on a 4-speed are longer than that of a 5-speed. For the best gas mileage while still using one of the 92-00 transmissions, try to get one from a 92-95 VX, 92-00 CX, or 96-00 HX. These will have the best gearing for gas mileage. The next category would be 92-00 DX and LX transmissions, which have shorter gears than the VX, CX, and HX, but still have longer gears than their 92-00 EX and 92-95 Si counterparts.

Note: Out of 92-00 Civics, the only transmission that will not work for you is the 99-00 Si. This is because the engine is actually a different series (B-series) than the other Civic transmissions (D-series), thus having different bolt patterns and etc.

 

Thanks for your impute base on what you are telling me it my not be worthed if my 4th speed tranny have long gears, and if my millage is not going to improve a great deal. Anything else I can do to improve gas millage on my ride, I here that if you lower your gas regulator will get you better gas per mille, but correct me if I’m wrong I don’t think that my car has a gas regulator.

 

I could be wrong about your gears being longer, but I am pretty sure that is the case. I'd need to get that verified by someone before I could call it fact.

i'm not sure if you have a fuel pressure regulator

but, only an experienced tuner should mess with stuff like that. if you set it too lean, your engine will suffer a horrible premature death.

 

So finally what can I do to improve gas millage any advice

 

Well, what kind of gas mileage are you currently getting? I'd imagine it should be pretty good.

First, I would do a complete tune-up (spark plugs, plug wires, air filter - i'd get an OEM fitment K&N filter, etc.) Also, run some seafoam through your engine, and then a couple hundred miles later, change the oil with some synthetic oil. Change your transmission fluid, with some new Honda Manual Transmission Fluid (new fluid should let your engine rev more freely than the 19 year old fluid that's probably in there now)
A good running engine will get better gas mileage than an engine with maintenance that needs to be done.

I'm not sure exactly how much gas mileage you will gain if any at all, but i'd imagine you should gain a little bit.