Anyone notice the 2 MPG increase on 2012's?

[Madcowranch]

Most vehicles keep fueling the engine when you take your foot off the accelerator, it's not as though they're putting it in neutral. The slower rate of deceleration that results is because they're continuing to give the motor gas, which of course is completely wasted if you're on the brakes too. Deceleration fuel cutoff is a good thing and can improve economy quite a bit. If you want the traditional behavior, just keep your foot slightly on the gas.

Hey droid I believe that is erroneous info. Most modern engines cut fuel while in gear and coasting. Your engine would actually burn more fuel if you put it in neutral and coasted.

 

[Humvee21]

Hey droid I believe that is erroneous info. Most modern engines cut fuel while in gear and coasting. Your engine would actually burn more fuel if you put it in neutral and coasted.

I've read about this before but I cannot provide any backup or anything that would negate this statement about neutral being worse than coasting in drive.

Anybody know why this is and can offer a better explanation?

 

[swoop1156]

Raptor has a drag coefficient somewhere between that of a flat plate and a parachute. From what I've seen the only significant benefits come from just driving slower, which is pretty darn impractical.

I needed a good laugh after ranting about the unicorn bumper. HAHAH! This was awesome.

 

[Droid]

Hey droid I believe that is erroneous info. Most modern engines cut fuel while in gear and coasting. Your engine would actually burn more fuel if you put it in neutral and coasted.

Yeah, I shouldn't have said it like this. From what I've seen most vehicles don't seem to make much use of it (deceleration fuel cutoff) though. My '04 GMC had it, but it would only go into deceleration fuel cutoff except in a few conditions...e.g., letting off at 70 in OD wouldn't do it until I lowered the RPM threshold for DFCO using EFILive.

The general belief was that manufacturers didn't make heavier use of DFCO because people didn't like it, they wanted to feel like they were able to "coast" even though it was less efficient.

 

[f16YODA]

My '04 6.0L F-250 does the fuel cutoff thing anytime I let off the gas and the RPM is above ~1200RPM. I understand this is a typical thing for diesels but not for gasoline engines. Anyone else have any expertise or real world experience?

- YODA

 

[BDRAG]

My '04 6.0L F-250 does the fuel cutoff thing anytime I let off the gas and the RPM is above ~1200RPM. I understand this is a typical thing for diesels but not for gasoline engines. Anyone else have any expertise or real world experience?

- YODA

If I pop the Raptor into neutral at 70 mph to coast down a long hill, the rpm stays at 2000 and decresses as the speed decreases. I would guess to match rpm to speed. I know this was discussed back in the first of the year when I mentioned it. I do not do it anymore, coasting. Now in my wifes CRv the shifter rocks between Neutral and drive without having to push any button. This allows the tranny to ingage and disingage and the thing coasts down hill like a cats eye marble. You can save 10% on milage if ya try hard and keep it below 65 mph. In town is where ya see the gain in the CRV. Coast up to stop lights and down hills.

BDRAG

 

[Deinonychus]

You can usually get better MPG without cruise control. Cruise control cannot adjust to things such as hills.

Good practices to increase MPG:
1. Coast to red lights, traffic lights, or slowed traffic.
2. Accelerate downhill (but not too hard).
3. Decelerate (a little bit) or maintain current speed when going uphill.
4. Try to maintain speed on the highway.
5. Avoid changing lanes too much (this causes you to speed up or slow down without you realizing it sometimes).
6. You can practice drafting on the highway but make sure you do it safely. (No, drafting is not the same thing as tailing...)
7. Windows up on the highway!
8. No A/C.
9. Accelerate smoothly to your cruising speed.

There are other things such as weight reduction and what not but I just want everyone to understand how to change their driving habits in order to achieve more miles per gallon.

I see a potential problem here if you are too far from the optimal torque rpm, which would be a less efficient method of achieving your desired speed. You could make the argument that a little more aggressive acceleration might produce a better mpg. You would be less time at a less efficient rpm range of the motor. Something to think about.

 

[Boostin]

I've heard that a gas engine is most efficient at redline so doesn't that mean we should be driving around with our foots to the floor?

 

[6.2]

I've heard that a gas engine is most efficient at redline so doesn't that mean we should be driving around with our foots to the floor?

Yup!


-Sent from my iPhone

 

[Humvee21]

I see a potential problem here if you are too far from the optimal torque rpm, which would be a less efficient method of achieving your desired speed. You could make the argument that a little more aggressive acceleration might produce a better mpg. You would be less time at a less efficient rpm range of the motor. Something to think about.

Good thinking. However, I have thought about this. And from my personal experiences I have concluded that quicker acceleration does not help. In fact, it worsens it quite a bit. Yes, you may be accelerating for a shorter period of time but you're also accelerating at a higher rate and the decrease in efficiency of doing this certainly outweighs the shorter acceleration time.