Mustang neutral coasting? (in Ford Mustang V6 automatic)
 

I tried posting this in another part of the forums, but I got no replies, so I'll try over here.:D
I'm just starting in my quest for much better fuel economy. I'm driving a '94 mustang convertible equipped with a 3.8 liter v6 and an auto tranny. I'm wondering if any one has tried neutral coasting with the AodE trans? I don't want to kill it!
Also, can any one tell me if this car is equipped with a fuel cutoff when I take my foot off the gas?
I'll be ordering a scanguage here soon for more accurate monitoring. Any help will be greatly appreciated! Thanks in advance!!:thumbup:

-John

Every modern fuel injected car has fuel cutoff under certain conditions.

Coasting in neutral - you can almost certainly do it with the engine running, without damaging anything. As for shifting back into gear, I'm not so sure. Maybe someone with more experience driving the Fords can jump in here.

Coasting in N with the engine OFF requires that the transmission can be "flat towed" (drive wheels on the ground) in N. Otherwise you could be risking damage due to lack of lubrication.

PS - you'll love the ScanGauge. Fun fun. :)

Thanks MetroMPG! :) I am pretty excited about the scanguage. I'll be ordering it as soon as I save up enough. I checked my owner's manual and am a bit confused. It says the car can be towed in neutral, but says to keep the speed below 35 and not to drive more than 50 miles or transmission damage may occur. Under what conditions will the fuel cutoff be activated?

Pretty much anytime you're using the transmission to slow you down ever so slightly(on a downhill) or if the car doesn't require the engine to be loaded to maintain speed when coasting.
Sounds like the AODE can't be flat towed. Bummer.
What MPGs do you get in that? My '95 GT got about 21 for my everyday commute when I drove fairly reasonably. My lowest ever was 18, and my highest ever was 23 (all highway in 5th gear)
btw, you can swap transmissions in that beast fairly easily, but I don't know that you'd be able to EOC anyway, even with a 5spd - I destroyed the rag joint in my steering shaft by turning the car without the power steering on just a few times, and it was HARD!

Did you loop the lines? Add a breather? Or just disconnected the belt?

on my 2001 ford explorer sport (5r55e auto trans, the AODE/A4LD's replacement), here are my observations:

EOC = bad idea
N-coasting (engine on) = ok, if under 35 mph
"rev matching" (to go back into gear from N) = bad idea


when i coast to a stop sign/red light, i shift into N right under 35 mph. if i stop, i leave it in N, but shift into D when i know i'll have at least 3 full seconds for the trans to "find" gear, without pressing the gas. same if i have to take off again without stopping. shift into D, wait 3 sec, then start lightly on the gas.


btw, i came to these conclusions based on what didn't make my trans bang and jerk horribly into gear.

You might try some easy mods first. Here are some that come to mind:

1. Replace rear end lube with a pure synthetic replacement. (reduced friction)
2. Increase tire pressure to 10% over door label recommendation. (reduced rolling resistance)
3. As you are driving a 10+ year old car, you might consider replacing all vacuum hoses. Any vacuum leak really upsets the idle quality and gas mileage.
4. Clean the intake assembly and throttle body as well.
5. If it hasn't already been done, perform a thorough tune-up on the car using high quality replacement components.
6. Switch to synthetic (or Motorcraft synthetic blend) motor oil of the recommended weight. (reduced friction)
7. Thoroughly wash/clean the entire vehicle, including the underside. (reduce weight - grime is heavy)
8. Remove any unnecessary items from your vehicle, or replace with light-weight items. Donut spare intead of full-size, 5 pound tool kit instead of 50 pound tool kit, etc.


9. The Scangauge is a very useful tool for improving your driving habits. If you are on a tight budget, maybe you could look around and find a used Scangauge I for sale.

10. If you still have the original O2 sensors on the car, you will want to consider replacing them, although that can get pricey.


Good luck.

Wayne

I've driven a few Mustangs lately and noticed that they like don't like to tach-down between shifts or on decel, so fuel-cut may be reduced (similar to some Tarurus models). Do you experience that or is there a fix? The worst was on an '04 (?) Mach-1 manual.

-Rick

Before you spend money on a Scan Gage, check and make sure your 1994 'Stang is OBDII compatible.
I believe the older Fords were still running EEC4 at that time which is NOT OBDII.
Just a little insight,
Schultz

When it says it can't be flat-towed in neutral above 35mph, means you can't EOC. You shouldn't EOC in an automatic anyway. BUT, you can neutral coast with the engine running in an automatic. When shifting back to Drive, wait a second or two then apply gentle throttle. It should be pretty bumpless.

96 and above was OBDII on most vehicles, and even some of those didn't fully implement OBDII. Looks like your 94 Mustang can do Scangauge. Some of the nicer (read: expensive) vehicles were always a little ahead of the masses.

One of my Broncos has an AOD, but not AODe. Neutral coast in that often. My Bronco C6 and F250 Diesel E4OD neutral coasts just fine. Engine running in all 3, of course.

Ok, so engine off coasting is a no no with my car, but engine on coasting sounds possible. I think I'll try it first at slow speeds and work my way up just in case. Gascort, my v6 seems to be getting about the same mpg as your v8!:( I was also concerned that the scanguage II wouldn't work with my '94, but I checked the list of compatible vehicles on the scanguage site and the '94 mustang v6 is listed. I haven't really done anything yet and I'm already having fun! Impossible sounding fuel mileage, here I come!:turtle:... :D:D

I have done a few engine on coastings of a mile or less in my 94 Mustang so far and have not had any problems. Granted I have only done it about 5-6 times so not a lot of data to take information from but its something. What kind of mileage are you currently getting and what have you done so far?

So far I estimate I'm getting around 20mpg. I have yet to do any mods, but have been trying different driving techniques to find out what works for me. What seems to work for you Spac3dog? What mods have you done?

Only thing I have done so far is up the pressure in my tires to 45 psi and work on my driving style. Taking off slow from a stop ,trying to keep the RPM's down as much as possible and cleaning all the excess stuff out from the car is all I've done so far. And to add in I just got back from a 326.3 mile trip where I stayed between 65 and 75 mph depending on the semi truck in front of me and shattered my old record mpg. When I filled up I got 30.725 mpg and I still had 5 gallons left in the tank which would have got me 460 miles out of one tank had I kept going at that rate. I'm looking into getting/making some smooth covers for my rims and making a upper and lower grill block soon for my first mods. Oh and I still have an O2 sensor throwing a code so I'm sure that's not helping things any.

JRK5150,
I've been doing neutral engine on coasting in my 2003 Taurus for a couple years with no noticeable problems as of yet. I use the same method as 99METRO. When shifting back into drive while coasting, wait a couple of seconds for the tranny to get back to the right speed then go light on the throttle. I have pushed the coasting speed a bit higher and have had no problems with neutral coasting at 45mph. I'm probably asking for trouble but so far so good. I'd only suggest coasting at this speed if you're comfortable with the possibility of blowing your tranny. JJ

Ok, I've tried neutral coasting a couple of times recently. Mostly to red lights, always at a fairly slow speed. So far so good! =) I haven't done it enough to see any mpg increase, but everything seems just fine mechanically. I think I'll incorporate more neutral coasting into my driving style and see if I notice better mileage over a period of time.

If you need to brake, try dropping it a gear (rev-match if you can) and you'll end-up with a lot less on the fuel consumption (DFCO). Let the compression do the work...

RH77