Better gas mileage with ETC Power button on. Anyone else?

Late to the party on this one but I too have noticed the same thing. My theory is that with ECT PWR off, the engine shifts too soon and sort of bogs, prompting the driver to press the gas pedal further, which tells the engine to inject more gas into it. Whereas I noticed when ECT PWR is on, it stays in the lower gears longer so I barely need to press the pedal at all to maintain speed or even speed up. I will be driving with ECT PWR on full time now!

 

This same conversation used to happen with 1st gens.

+1

 

For the sake of not starting a new thread, I tested this yesterday.

(Edit for model: 2019 DCSB OR 4x4)

Had a quick turnaround to AZ and back from LA. 250 miles each way. ECT off, I got 19MPG on the way there. Filled up in Parker AZ. ECT on I got 22MPG on the way back.

Didn’t use the onboard monitoring for the numbers, did it the old fashion way with math.

I couldn’t seem to find a definitive answer on the topic of using ECT full time, will this cause long term issues, or should I just hardwire the MFer on?

 

I get a good 4mpg loss across the board with the ECT on. Which makes sense, since you are always running a gear lower and at higher rpm constantly over the non ECT map. Also the throttle response is touchy, using more fuel. 18/22 with ECT off and 14/15-18 with it on. Think of it as eco vs normal mode, with normal being the ECT on

 

I tried this today. Took a trip only differences was on way back i had our 9yr old son. On the way non ect it used 12.3l/100km and on way back i had ect on and the gauge said 9.5l/100 so approx 4mpg more with more uphill on return. According to Toyota using ect will decrease. Opposite of what happened. I'm kind of considering putting in ect always on mod

 

I definitely get better fuel economy with the ECT on, I also found running 91 helps and also idles way smother than with 87. My commute is 32 miles each way and I drive over an 1,808 foot mountain road everyday. ECT doesn’t let the engine bog as much and it’s literally the difference between my tank getting 20-22 if I somewhat baby it, to 18-19 with 87 and no ECT. I’ve tried it both ways and ECT and 91 I almost consistently get 2-4 mpg better per tank.

 

I have noticed that with ECT on I get a touch better mpg as well, and I don't have to listen to the engine bog then wait to the transmission to down shift and send the RPM's way up just to get me moving on some of the hilly turns.
My usual is 23 MPG (V6 2WD DCLB 245/75-16's) Im sure the tire size makes a big difference.

 

Haven't tried the ECT mode other than towing...got almost 19 mpg pulling my boat using S5 and ECT. Normally i get the best fuel mileage in the D mode using 87 fuel while keeping it around 50-60 mph with low rpms on our back roads here.

 

Does the ECT only change the gearing or does it also change the fueling?

 

I'm pretty sure ECT only changes how the computer allows the transmission to shift and how that corresponds to the fuel management system.

 

Can't say I've had the same experience. Maybe I'll try it for my next round trip commute and update for sure. But I'm also not getting as bad of MPG as OP was getting. In the summer with my tire pressures higher (thanks to the dealership) I would get about 22-23 MPG at 70 MPH without ECT. I can see how ECT would make a difference if you're having to labor the engine though such as carrying a load, mountains/hills, or all that combined with higher speeds.

 

As far as i know ECT just delays the transmission shifting points. Never knew it works with and conjunction with the fuel system. I've had ect in my 4 bangers way back when toyota started building these compact 4wd trucks.

 

This has been an interesting thread so, I pulled out the manual. I don’t know you all are located but maybe the photo may give a bit insight. Now, I just got my Tacoma a week ago so I’m a newbie.

 

Yes.
But that doesn’t answer most of the questions on this thread.

 

Maybe OVTune is something look into?

https://www.tacomaworld.com/threads/vf-tuner-for-the-3-5l-tacoma.662948/

 

what....no pics of etc button on....

 

I think it plays with the fuel mapping too. I'm pretty gentle on the pedal when leaving intersections (most of the time). This morning I tried ECT because of this thread. It definitely gets going a little quicker.

As an update to my experiment, I got about 1 MPG worse today with ECT than I did yesterday without it. 45 mile commute and I use cruise control. I suspect that the speeds I was going though would be more than fine without ECT. If I was pushing 80, I'd probably see a difference in a positive way.

 

I think the only reason it gets there quicker is your pulling higher rpm longer throughout the gears...which creates more power, (engine gets more into its power band), instead of the normal short shifting you get in the drive mode while having lower rpm.

 

I think normally, yes, but this was noticed from a dead stop. It seemed to "jerk" forward from the stop a lot more than without it. That's the only thing that leads me to believe fuel mapping is affected too, even if just barely.

 

I didn't like driving around with ECT on since it made the truck lurch/jerk when cruising around with no additional weight. But I once I started driving around in S5 I noticed my MPG go from an avg of 18ish to 20ish