Yes- it can be done, but you will likely need custom wiring, engine/transmission mounts and axles due to the way things are made different between the accord and civic.
It will likely increase your mileage somewhat- but the extra frontal area will hurt highway mpg (more drag) and the extra weight will affect stop and go mpg unless you really planned out stoplights so that you seldom used the brakes. You also wouldn't have as much acceleration (when merging onto a busy freeway).
What type of mpg are you getting now? It would be a lot easier just to swap in a manual transmission (assuming that your accord has an automatic)- this will likely help your mileage somewhat.
I did it with my 94 accord. I am able to get 33-34 mpg on long interstate trips (65-70mph) in the summer with some ac usage.
The non-vtec civic motor will have even less hp when you might need it and would still present the same challenges (axles/engine mounts/wiring).
If the accord is running good, you could just sell the accord and buy a vx. or buy a 92-95 civic and do the vx engine swap to the civic. It would be much simpler and cheaper and would get you better mpg numbers than swapping the vx engine/tranny into the accord.
Some people complain about how slow the stock VX is, I couldn't imagine that engine + drivetrain in an accord... Only thing I can suggest for the OP is to look for various accord transmissions and find the one with the tallest gearing. Either that or find a good transmission mechanic and see if you can either swap a final drive from another transmission that will fit or get a custom final drive made or something. I don't know a lot about transmissions so I can't be much of any help.
I would alter that car in this order:
- manual transmission swap, light flywheel, good clutch
- lightweight crank pulley
- stainless steel header and downpipe, wrapped in header wrap
- tuned ecu to lean out the cruising air/fuel ratio
- low rolling resistance tires
- underbody panels
So, it all depends how much you can afford. Also, do you own the DX/LX or EX model? Either model had engine compression of 8.8:1, vtec or not. I'm thinking the stock cylinder head isn't too efficient in moving air in and out. Maybe look at a doing a head swap? I don't know enough about this part to tell you more. Get registered at honda-tech or someplace like it and research your options.
But still, with the changes mentioned above I bet you can get into the upper 30's mpg on the highway.
Frankly chris, I don't see why you can't just get a different car. I went on autos.msn.com and compared the specs of the '95 accord (94-97 generation) with the '96 Honda civic ('96-'00 generation) and while the accord is about 10 inches longer, it only has 1 cubic foot of more trunk space (13 cubic ft. vs 12 cubic ft), the front and rear head room and legroom is within fractions of an inch, only 130hp in a 2.2L engine compared with the Civic EX's 1.6L 127HP engine all the while the Accord weighing about 500lbs more. If you just got a '96-'00 Civic or the even bigger '01-'05 Honda Civic, I don't think you'll be missing anything over your '95 accord and will see a nice MPG improvement while also having a platform that is more easily modified for fuel economy improvements. Now if you had a much newer Accord like '03+, then yeah you'd be losing space but because this generation of Accord is so small as it is, you wouldn't be losing much by going with a Model year 1996+ Honda Civic. I choose my 1998 Honda Civic 4 door over the '92-'95 Civic specifically because of the head room and legroom which was more than that of the '92-'95 Civic, plus it being side impact and offset crash tested by the IIHS. If you want an even bigger car without a sizable weight gain (weighs similarly to the '96+ civics), you can go with the '01-'05 Honda Civics and can probably still match a VX transmission to those engines as the Honda D series engine was used in the Civics all the way till 2005.
If you do decide to go with the '01-'05 Civics, get the VTEC version because they're all VTEC-E and have improved low RPM torque over the non VTEC civics which makes it a prime candidate for a transmission swap assuming you go with the manual transmission version. The VTEC-E in the '01-'05 Honda Civics mixes the best of the VTEC-E (low end torque) and VTEC (high end power). Essentially, 12 valve mode from idle to 2500rpm and a high performance 16 valve mode from 2500RPM to redline, giving a peak HP of 127, just like the '96-'00 civics.