Is 50mpg asking too much???
 

I don't want to do anything that will require the ICE to be turned off.

I'm sure with a couple of mods I should achieve 45mpg. Thanks to Matt's help I found the parts that I wanted to replace.

Here is my plan so far...

-Distributor cap
-Distributor rotor
-NGK spark plug wires
-NGK spark plugs
-Replace entire PCV system(not just the PCV valve)
-Tires at max psi
-Get 2 LRR tires since I still have 2 tires that are good.
-Belly for the rear of the car
-Fuel filter
-Air filter

So do you think with these things 50mpg can be achieved?

It really depends on your drive. How long is your typical drive? Can you provide speeds, %city? How many cold starts per tank? Cold starts kill your FE.

With the Del Sol I could get 55MPG without turning off the engine. That is with 20 cold starts per tank and each trip was 25 miles, 50/50 city/hwy, 55 MPH max speed. I would think that you should get similar results with your DX.

I don't see those mods raising your FE at all unless something is seriously wrong with one of those things. Mehbe a little bit from tires...

Why replace the entrie PCV system?

Agreed. Just tuning up your car is a good idea, and will most likely give you 1-2MPG, but it won't really fix anything unless you had something seriously wrong.

On the altima I replaced some stuff that I felt wasn't working at it's best and it increased my mpg.

I'm also working on driving technique. So hopefully I'll break 45mpg with all that stuff and my driving technique.

The PCV system has some stuff bad on it and some stuff that i just don't want to check and just replace.

What makes you sure it's bad though? I've never heard of anything besides the valve failing or the hose getting clogged. I doubt the breather box on a 7 year old car would go.

I'm not replacing the breather box. I'm replacing everything around the PCV and the hoses.

Oh, well then, that makes more sense, :p

Can 50MPG be achieved? Depending on your commute I don't see why not...

By comparison my Civic is ~200# heavier than yours, is sporting 4.07 final drive automatic transmission, and I clicked off my first 50.X MPG at this morning's fillup. No ICE off tactics - engine spinning the entire time I'm driving.

I'll argue that you need to get instrumented to really push yourself (my scangauge has been the difference), but I take it from past threads that that's not what you want to hear...

Congrats lindermant - looks like a record tank? I think it's possible (personally) to eke out very good city FE without instrumentation (p&g and codfishing oriented), but it's crucial for decent highway numbers. The difference between good and great cruising/instant mpg is imperceptible without feedback - unfortunately, unless you've tried it you likely won't believe that statement.