To downshift or not...?

[Charlie1717]

If you cut someone off you best be hitting the gas... not the brakes.... Just saying
But I am a coaster and I would say brakes over acceleration any day. But I can see in some cases you may need to accelerate and in reality the amount of time you would have to shift then accelerate would most likely not be enough (assuming you are coasting in neutral).

I'm not saying it is safer to stay in gear but I'm also not saying it is just as safe to coast in neutral. Neither side is right. And neither one of you will persuade the other. It's just a matter of opinion.

[Pu241]

And neither one of you will persuade the other. It's just a matter of opinion.

No doubt true, as we have learned in other "sensitive" topics.
But, I love the phrase "I'll argue this with you until I'm blue in the face."
I just want to see him turn blue.

[Oren09]

I'm reminded of the song I'm Blue by Eiffel65.
Lol.

[resuwrecked]

If you guys are coasting in neutral to save gas I hope you are also shutting your engine off. Coasting in gear you go into fuel cut, burning no fuel. Idling, your comp is keeping afr's around 14.7. Doesn't make a whole lot of difference since time spent on decel is minimal compared to driving unless you are looking for that extra .5 mpg. Just keep out of the gas (or out of boost for us 'charged guys) a few times and there's your .5 mpg for the tank. I personally downshift. It aides braking (since our cars suck at that, even with an aspire swap). I don't care about clutch wear because I don't slip it downshifting. Its the acceleration that makes mine slip. If you ride motorcycles too then I hope you downshift. To each their own, just my .02

[easywind]

OK people I give up everyone is right I'm wrong. You may now call me Blue or anything else you desire.
bhazard I pass through Ohio twice a year, have friends in Maryville and in Youngstown so I do drive a bit. I've gotten over 46 mpg with both my Festiva and my Aspire.
I go from NY to arizona by car where I pick up my Ford F250, 24' Holiday Rambler travel trailer and drive down into Mexico about 100 miles south of Puerto Vallarta.
And what makes a safe driver? I've had two accidents in the 48 years I've had a licence.
One when I was rear ended at a traffic light the other when I lost control on ice when I was 18. Driving is total consentration, I don't play music, eat, games etc. I ride backroads when I can, which is almost always, I keep my equipment in perfect shape. I don't care about gas mileage nearly as much as I care about keeping control of my ride.
Now in the process of picking up a cross country ride. Looking at Toyota Camrys.
Peace

[JohnGunn]

Would someone pass the ketchup. I've got some words to eat.

What they said.

Except for this little tidbit:

I read recently that for best mpgs, you should let the car coast down in whatever gear you are in because putting it in neutral tells the ECU to give the engine a little gas to keep it running with no load. When you leave it in gear, the centrifigal force turns the engine and uses less fuel to keep it running. Take it out of gear before the engine starts to lug, then you come to a stop.

Now, if I'm wrong, or wrong for Festiva ECU mapping, someone please tell me. As I said, I just read it in one place and haven't confirmed this. It makes some sense, though.

Karl

OK, Karl. Just pass it over to me here in Coronado.

Take a part time job delivering pizzas. When your income is DIRECTLY affected by the way you drive, you teach yourself how to save money and your car. Coast in neutral uphill, coast downhill over 1600rpm in whatever gear. This will turn off your injectors and use less fuel than coasting downhill in neutral. Time your traffic lights and blow by the guy who sped up to just stop at the red. You might be going under 20mph for 1/8 mile but when it hits green you are in 3rd gear and never stopped.

Getnpsi, why don't you pass a small pepperoni over to me. Hold the pepper. I've got some ground up words to sprinkle on top.

Let me begin by saying all of what I wrote about the amount of fuel used when decelerating would have been accurate if the computer stayed in the "closed loop" mode during deceleration. (Pardon me while I pour some ketchup on this and sprinkle this black power.) But when the engine is decelerating the computer goes into a different mode. Guess what? It's called deceleration mode. I now insert information about that mode from my '90 shop manual.

On closed throttle deceleration, the engine requires a lean air/fuel ratio to reduce exhaust emissions and improve fuel economy. Deceleration is indicated by the IDL switch in the throttle position sensor. The ECA reduces the amount of fuel supplied through the injectors until engine speed falls below 2,200 rpm. The reduction is gradual to prevent "surging." When engine speed is less than 2,200 rpm, the ECA gradually returns the fuel supply to normal.

Oh, Getnpis, is it too late for me to get a Sprite with that pizza? Thanks.

Now I feel a lot better. I still don't know from this information how much of a difference this would be from coasting in neutral, but I am sure that my previous theoretical speculation has no bearing whatsoever on the issue.

I've noticed I get my best ideas after I clearly define a problem, try and address it, and then walk away from it and forget about it. Then sometime later, maybe when I wake up the next morning, I'll have a new thought about that problem, even though during the intervening time I had not given it any conscious attention at all. Even more significant is that the thoughts that come in this manner are invariably of a higher quality than what I had earlier achieved through my best concentrated effort. In fact, now I have begun to cultivate that process even though it clearly has a mind of its own. (Why was I not taught this in school?)

Anyway, here was the second thought that came to me the next day. If the computer maintained the same optimum fuel/air ration during deceleration at 1600 rpm, then the engine would, due to this amount of fuel, effectively be idling at 1600 rpm and there would be no engine braking at all. That sent me to my manual and the rest is (burp), excuse me, culinary history.

And, finally, what would a post from me be without some suggestion of a possible test to clarify matters? How about someone in Denver coasting down to Colorado Springs, once in neutral and once in a high gear, to settle this matter once and for all? I've got a defective Idle Speed Controller I'll send you for your trouble.

John Gunn
Coronado, CA

[Pu241]

Easywind,
Somethings are just not worth arguing about.
I try to put my opinion out there FWIW.
It all depends upon how something is practiced.
I hope you'll agree that even someone who never coasts can lose control of their vehicle if not vigilant. And certainly I agree that someone who coasts at every opportunity and inhibits traffic flow is a danger.
When I coast I never drop below 5 mph below the posted speed limit.
In my driving through mountains I have hit 80 MPH down hill, at those speeds you can coast a long way before dropping back in gear or dropping the clutch for re-ignition.

I wouldn't count being rear-end at a traffic light!
Don't think you could have done anything to prevent it.
I had the same thing happen to me on the NJ turnpike 4 lanes of parked cars with brake-lights on and some idiot in a van didn't see them. Hit me hard enough that I hit the car in-front of me, the driver of said car happened to be a lawyer. So there was some humor involved when the diver of the van tried to explain that his insurance would cover my car and my insurance would cover the lawyers car. The lawyer said only one thing; "unless he (referring to me) can prove you hit him with sufficient force that he could not avoid hitting me. Then you get to pay for both of our vehicles."

FWIW, your driving record is better than mine!

[Safety Guy]

Well, I guess all that finally answers my question!

Mr. Gunn, I'm fresh outta ketchup, but how 'bout some mayo?

BTW, sometimes I'm guilty of coasting with my engine off! Usually happens in a long descent at slow speeds.

Not supposed to do this in an automatic, though. I read (again) that with the engine off your transaxle does not get the proper amount of lubrication/cooling inside it, which causes extra wear.

Karl

[Joe Dirt]

i usually coast,these cars are not that heavy and i doubt it will even shorten brake life by much doing it this way.

[getnpsi]

If anyone has a a/f ratio gauge in the festiva, tell me if it goes all the way lean on a in-gear deceleration. If you just stick in the clutch while coasting it goes back to idle stoich.

[Biff]

Has anyone ever heard of "double clutching"for down shifting?
By down shifting through the gears in this manner you would have very little stress on the trans, clutch, etc. (not concerned with MPG)
Semi truck drivers typically only use the clutch for starting and stopping, the rest of the gears, up or down are shifted by matching engine RPM to gear ratio.

[Evil D]

^^ That's sort of what i meant by rev matching. It takes a lot of practice and is tricky when you don't have a tach.

[resuwrecked]

If anyone has a a/f ratio gauge in the festiva, tell me if it goes all the way lean on a in-gear deceleration. If you just stick in the clutch while coasting it goes back to idle stoich.

If you guys are coasting in neutral to save gas I hope you are also shutting your engine off. Coasting in gear you go into fuel cut, burning no fuel. Idling, your comp is keeping afr's around 14.7. ...

.
I have a wideband. It pegs out lean when decel in gear. It stays stoich when idling coasting.

[sasquatch]

^same...

[easywind]

PU 241 Wish you were my insurance guy when you said it wasn't my fault. I was charged with 50% of the blame and my insurance skyrocketed. Kind of like a unit citation award in the service, you get it cause you were there. Yes and anyone can lose control. I grew up when gas was 23Cents a gallon so I learned different techniques.
And I hope this does not turn into an arguement from evil d but one downshifts (in my universe) by ear not looking at a tach.