Using DFCO to increase your MPG - Toyota Yaris Forums

Darb · 05-08-2009, 12:06 PM

Quote:

Originally Posted by BailOut

Now tun off your ignition (This is where you may lose your PS/PB, so be wary!) and watch for any harsher deceleration or change in the pitch of the engine for a few seconds.

Whoa whoa, question. Doesn't the AT require you to be in park (P) in order to restart the engine? Or are you just shifting down to 3 and L? *confused*

BailOut · 05-08-2009, 12:20 PM

Quote:

Originally Posted by Darb

Whoa whoa, question. Doesn't the AT require you to be in park (P) in order to restart the engine?

Hello Darb,

No, you can start it from N(eutral) as well. However, if you would like to do it from P(ark) you still have your power brakes after the engine is off for at least 4 touches.

Marthos · 08-04-2009, 06:38 PM

Lets make this simple.

DFCO is for slowing and/or stopping the car,

If you need to stop at the bottom of a hill, or you want to go slower down a hill, DFCO is for you.

Start down the hill, Auto Trans people may need to tap breaks or even downshift into 3, Manual people just let off the fuel pedal.

The engine will start to try to slow the car, at this point your not using ANY GAS (DFCO).

When at or near the bottom apply brakes, when stopped put trans back into D (which is really OD). If you were just slowing the car some, just pop it back to D and hit the go pedal!

You saved gas.

If you were to bump the car into neutral, all the stopping would be on your brakes and the engine would Idle (use some gas) all the way down.

If you need to coast after the bottom of said hill, DFCO is not for you! Coasting on flat ground requires forward momentum, DFCO Scrubs forward Momentum.

If DFCO slows the car to much and you find yourself back on the Go Pedal before the bottom, you are not saving gas.

DFCO stops your fuel injectors from injecting fuel into the cylinders.

R2D2 · 08-04-2009, 10:57 PM

Quote:

Originally Posted by Marthos

Lets make this simple.

DFCO is for slowing and/or stopping the car,

If you need to stop at the bottom of a hill, or you want to go slower down a hill, DFCO is for you.

Start down the hill, Auto Trans people may need to tap breaks or even downshift into 3, Manual people just let off the fuel pedal.

The engine will start to try to slow the car, at this point your not using ANY GAS (DFCO).

When at or near the bottom apply brakes, when stopped put trans back into D (which is really OD). If you were just slowing the car some, just pop it back to D and hit the go pedal!

You saved gas.

If you were to bump the car into neutral, all the stopping would be on your brakes and the engine would Idle (use some gas) all the way down.

If you need to coast after the bottom of said hill, DFCO is not for you! Coasting on flat ground requires forward momentum, DFCO Scrubs forward Momentum.

If DFCO slows the car to much and you find yourself back on the Go Pedal before the bottom, you are not saving gas.

DFCO stops your fuel injectors from injecting fuel into the cylinders.

Exactly what I have found. If I don't need to slow on the hill or at the bottom I hold just enough pressure on the accelerator to prevent DFCO to gain momentum for the flat or the next uphill if safe to do so.

One of my favorite features about the Yaris AT is it is very user friendly in regards to engine braking. Down shifting/upshifting are very easy and effective due to DFCO and the way the shifter is set up.

R2

Yaris Hilton · 08-04-2009, 11:42 PM

The AT downshifts to hold back the coasting car if you touch the brake. Touch the gas and it upshifts to coast freely.

Marthos · 08-08-2009, 02:01 PM

Also, the tranny will not down shift till rpms are safe.

I have tried it on a 1/4 mile, big downhill grade leaving my home lots of times, with a stop sign at the bottom.

i pop it into 3rd going 40, and it downshifts right away and revs ups a tiny bit, when i pop it into 2nd it almost always downshifts right away (2nd goes past 50mph if ya floor it from a stop) rpms go up, sounds kinda cool, then when im at around 25 i pop it to 1st and have to hit the brakes for it to downshift. I think it shifts down when im around 18 to 20 mph.

I dont have a tach, but I am sure it never revs past 5k after it downshifts, I think there is some kinda over-rev saftey lock out possibly?

The whole process seems very nonharmful to me, and i know im saving a little gas and a lot of brakes.

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08-04-2009, 06:38 PM	#3
Marthos View User's Garage Drives: 07 3Dr LB Join Date: Jul 2009 Location: NEPA Posts: 58	Lets make this simple. DFCO is for slowing and/or stopping the car, If you need to stop at the bottom of a hill, or you want to go slower down a hill, DFCO is for you. Start down the hill, Auto Trans people may need to tap breaks or even downshift into 3, Manual people just let off the fuel pedal. The engine will start to try to slow the car, at this point your not using ANY GAS (DFCO). When at or near the bottom apply brakes, when stopped put trans back into D (which is really OD). If you were just slowing the car some, just pop it back to D and hit the go pedal! You saved gas. If you were to bump the car into neutral, all the stopping would be on your brakes and the engine would Idle (use some gas) all the way down. If you need to coast after the bottom of said hill, DFCO is not for you! Coasting on flat ground requires forward momentum, DFCO Scrubs forward Momentum. If DFCO slows the car to much and you find yourself back on the Go Pedal before the bottom, you are not saving gas. DFCO stops your fuel injectors from injecting fuel into the cylinders.

08-04-2009, 11:42 PM	#5
Yaris Hilton Half a Bubble Off Plumb Drives: 2009 Yaris Sedan Join Date: Mar 2009 Location: Bristol, Tennessee, USA Posts: 1,593	The AT downshifts to hold back the coasting car if you touch the brake. Touch the gas and it upshifts to coast freely.

08-08-2009, 02:01 PM	#6
Marthos View User's Garage Drives: 07 3Dr LB Join Date: Jul 2009 Location: NEPA Posts: 58	Also, the tranny will not down shift till rpms are safe. I have tried it on a 1/4 mile, big downhill grade leaving my home lots of times, with a stop sign at the bottom. i pop it into 3rd going 40, and it downshifts right away and revs ups a tiny bit, when i pop it into 2nd it almost always downshifts right away (2nd goes past 50mph if ya floor it from a stop) rpms go up, sounds kinda cool, then when im at around 25 i pop it to 1st and have to hit the brakes for it to downshift. I think it shifts down when im around 18 to 20 mph. I dont have a tach, but I am sure it never revs past 5k after it downshifts, I think there is some kinda over-rev saftey lock out possibly? The whole process seems very nonharmful to me, and i know im saving a little gas and a lot of brakes.