ZenDog73

Trying to get best fuel economy, out of D16Z6 V-TEC w/headers, intake, & exhuast. On one tank i'll get about 38 mpg on another about 32.. Any ideas??

bnetkillzone

Depends on tranny for RPM's. Coast in gear whenever possibly because you use no gas at all. And coast in neutral whenever else you can.

Usually for bigger hills I coast in gear and maintain constant speed, which is good because i dont **** off the other person behind me, whereas if I did that on a small hill, I would engine brake too much and lose too much speed and **** off the person behind me.

So if its a small hill, I would coast in neutral.

Whenever approaching a red light I coast in gear up to it.

If no one is behind me and im approaching a red light, it might be advantageous to slow down a distance behind the light and wait for it go to green while you are not stopped but going a slow speed like 10-15MPH, therefore you didnt need to stop. Get other cars to trigger the lights for you.

All depends on your driving conditions and traffic.

I get 35MPG, Injen CAI and Koni/GC. And I got it up to 110MPH on that tank too lol!

Shift at the lowest RPM you can without lugging or bogging the engine. For me it is usually 2,500RPMs on a flat road. Of course if its a hill you would need to shift at 3k+

ZenDog73

Thx, for info..

FlewByU352

I get more MPG beating the **** out of my car then I do driving like an old person. I calculated it several times and couldn't figure out the logic behind it. They only thing I came up with is a short burst of acceleration uses a lot of gas, but maybe less than a moderate acceleration where you are on the gas for a longer period of time.

turbohatch96y7

iTrader: (15)

Coasting in nuetral would waste gas think about it. Shift to 5th instead of neutral.

bnetkillzone

Depends on the situation. But yes coasting in gear with the throttle closed is the most preferred.

turbohatch96y7

iTrader: (15)

Situation doesn't matter. Once in neutral your injectors are pulsing.

fcm

Coasting in neutral on Canadian highways and roads is illegal, in B.C. it used to be an "undue care and attention" ticket, worth 6 points on your licence and $$$ when it is time to renew your insurance, now I see them handing out the new "stunting" ticket for that, same one they came up with to get people that "launch race" to "intersection racing" drag racing up to the speed limit or burning rubber or just about anything a cop thinks is showing off.

A stunting ticket will also get you 6 points, they can even tow the car, and that will cost you $150+ for the tow and impound fee.

Also as mentioned on a fuel injected engine it will not save you gas. 94

grumblemarc

iTrader: (4)

What you're talking about is called hypermilling. They have a whole site dedicated to it.

TunerN00b

California (and, if my memory serves correctly, most other states) as well.

ZenDog73

I don't care about the laws, whats the BEST FUEL ECO?
I live in Arizona! One of the last, Wild West's out there!!!
Whats the best fuel economy???

grumblemarc

iTrader: (4)

This question is barely English, let alone does it make sense. Hypermilling. Google it.

IN VTEC

iTrader: (3)

Get a DX transmission.

DCFIVER

RPM does matter. The lower the engine speed the less fuel it will use. That is why most newer MT cars have 6 speeds. It is almost always an OD gear.
This is correct.Somewhat. The injectors are not completely cut off under extended coasting (IE down a hill) but are pulsed enough to keep the vehicle at idle speed. Coasting in neutral DOES NOT waste more gas than coasting in gear. Even 5th gear. That's ridiculous...

IN VTEC

iTrader: (3)

It's a compromise and it's situational.

If the car coasts down, in gear, then it uses no fuel but decelerates faster.

If the car costs down, at idle, then it uses a little fuel to keep the motor running at idle but can maintain coast down speed longer.

The situational part becomes a factor because it can limit the amount of deceleration time you have.


And....load is a third input, along with throttle position and air temperature. You may also want to consider engine warm-up time (if it's really cold in your region and if it takes a long time for the engine to reach operating temp).

You can't control air temperature so I would take it off the table. And, since we're only talking about driving, we should assume that the engine is already at temp.

grumblemarc

iTrader: (4)

All of this is just a rehash of what is already on this site.
http://www.hypermiling.com/

bnetkillzone

Good info. Exactly what I was trying to tell turbohatch up there...

turbohatch96y7

iTrader: (15)

I hear what your saying but who's going to coast down the road at 10mph?

kp

I was under the impression that all fuel-injected engines ever produced have the "deceleration" feature that cuts the injectors when you're not pressing the pedal. Is this not one of the primary benefits of injected vs. carb'd?

Of course, like other have already said, when coasting in neutral the injectors have to fire to maintain idle. However when in gear there is zero fuel being used when coasting.

got-vtec?

iTrader: (4)

what are these points you speak of?

turbohatch96y7

iTrader: (15)

When. Ur old enough to get your license you'll find out.

fcm

In B.C. when you get a ticket, [moving violation] like speeding or stunting, you get points against your licence, any more then 3 points and it will cost you more to insure your car and it can get very expensive, I know guys that pay 2-3 times the insurance price because of the number of points on their licence and will be for some time as you only loose 3 points each year you drive without a ticket, so 2 or 3 stunting tickets 12-18 points will take some time to get rid of. 94

DCFIVER

So engine speed means nothing? LoL....

Clearly....

DCFIVER

I should clarify deceleration fuel cut off for some of you confused individuals that have replied here. DFCO is a misnomer. The fuel in a fuel injected vehicle never completely cuts off. If it did, the vehicle would shut off every time you came to a stop after letting off of the gas. In reality what happens is the pulse width of the injectors is lowered to that of below the idle on time. Typically, injector PW at idle is around 2-3ms (miliseconds) During deceleration the injector PW is lowered down to 1-1.5ms. Injector PW is NEVER at 0ms as long as the engine is running. Engine speed plays a huge role in injector PW. When engine speed reaches 1000 rpms or lower and the throttle plate is closed, the PCM believes the vehicle is at idle. It will then increase the injector on time appropriately.


If any of you have access to a scan tool that shows injector PW, you can veiw these events for yourself. The injectors are constantly pulsed for 2 reasons:

1.To prevent stalling
2. To keep that cat at operating temp.

TunerN00b

Engine speed means much, much, less than engine load.

It isn't uncommon to find a modern engine that burns less fuel at a higher rpm than a lower rpm at the same speed, due to the increased load caused by the taller gearing.