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.

I hauled *** this tank and still pulled a 38.5mpg tank. I'm sure if I'm easy on the gas I can make a 40mpg+ tank.

I'll wager my "butt dyno" will beat your scanguage, and I'll tell you why: anticipation! I can plan ahead for situations the scanguage only "sees" when it's too late...it's into them. -Ted Hart

That may be more difficult than you might think. There have been times when I thought I was pressing as light as possible on the pedal but, by watching the SG, I found I could let up even more and still maintain my speed. Also, there have been times when I swore that it felt like I was letting up and found that I wasn't. There are a few people who can do well without a SG or equivalent but the larger majority of the people aren't as practiced and need the extra help.

I suspect you're referring to 2 different driving circumstances, and each of you is right for the one you're talking about.

Instrumentation can't teach proper anticipation of significant changes needed to preserve FE (ie anticipating traffic flow/lights).

Neither is the butt dyno sensitive enough to deliver feedback needed to feather the throttle to a very high degree when cruising, DWL, or bleeding speed imperceptibly.

However, you can't tell if you're reacting properly to certain things without some sort of instantaneous/trip feedback!

Someone I know of actually takes off their shoe and sock when getting real serious in driving for FE. They said it gives better control of the pedal and they were able to verify it with the SG. And yes, anticipation is important but, as SVOboy points out, the SG will will tell you how well you are reacting to that anticipation.
Edit: And no, the person mentioned isn't me; yet. :p

I wear mostly worn through canvas shoes for driving, best thing I've ever used, including barefoot (yes I tested all my shoes).

I was really amazed recently that I was correcting for inclines so perfectally that my speed would not vary more than 0.5mph - I kept looking at the MPG on the SGII and wondering why my foot moved - butt accelerometer works really well. But you're right about bleeding off speed - with the SG you can back off to 60-80mpg and slowly watch your speed decrease.

A quick calculation of gas use shows a little less than Half a cent per minute at idle is being burned in my xB if at 0.1gph = 2.133oz/minute. At $3.00 per gallon it would be $0.005 per minute.

The scangauge isn't driving the car, you are. On one hand you have your "butt dyno" and anticipation. On the other hand you have your "butt dyno", anticipation AND a scangauge. I wouldn't hesitate to be on the other side of your wager as long as your "butt dyno" isn't better than my "butt dyno".:p

I totally feel you Compaq...I want that 50 mpg tank so bad I can taste it!

I don't think a 50mpg tank can be achieved anytime soon. 45mpg looks plausible. I'm hoping that after the fuel filter, air filter, and pcv components get changed I'll be able to make 40mpg tanks with ease. So far I can haul *** most of the time and get a 38mpg tank.

If you want a 40mpg tank, quit hauling ***! It's really that simple.

Sometimes going fast is required.

I can't remember ever having the need to use full throttle in 25 years of driving. It you plan ahead, leave early and pay attention to the traffic around you, going fast is not required.

I was working on a resonse something like that and, since yours sounds better than what I had, I'll say, "Yeah, what he said!":p

need i say more?

SeaFoam or H2O once a year will do the same thing:thumbup:

Once in a while a speed adjustment is needed to accomodate other traffic and keep oneself out of harm's way. Sometimes it makes more sense to slow down, sometimes it makes more sense to get a little deeper into the throttle. That's defensive driving. But "hauling ***" is something entirely different, and isn't part of improving your fuel economy. Happy with your numbers? No problem. Not happy? Change. I'm just verbalizing common sense.

I was late to work a couple of times and nothing like some pedal to the metal cures that problem.

WOT acceleration might save you a few minutes. Why not plan ahead and leave earlier?

I do leave 5 minutes earlier most of the time but I got held up a couple of times.

Hopefully my current tank will be 40mpg.

I'll bet my butt dyno can whup your butt dyno! LOL! LOL!:D :p :rolleyes:

I bought my car (34/40) expecting to get an average of 35mpg, so i should be happy with my average of 40mpg. But it seems like i REALLY REALLY tried to incorporate changes to my driving technique... and it payed off, but only slightly.

normal driving when i got the car got me about 39mpg. My last fill up was 41.2mpg.

guess i should break down & get a scanguage as my next step?

I don't think you'll find anyone on this forum objecting to that advice, except maybe Compaq.

EDIT: looking at your gaslog, the car still has hardly any miles on it. It's also reasonable to expect it will improve a little more as the mechanicals break in.

true. i would love to see that magic 45 one of these days :)