ETC vs Normal...no tune.... efficiency.

@zoo truck this one is for you lol.
As some of you know I like to experiment and log data from time to time, recently a thread on this subject got my attention.
Which is better? Is one better around town? Do you get better or worse mpg's? Can you even tell the difference?
Alright. Truck is unloaded and driving is around town with max speed 55mph.
First, I examined the HP and torque formulas. Based on the formulas, the efficiency should be the same minus a few points for ECT because higher rpm which results in a bit more windage loss. But, you get the advantage of better torque ar 2000 vs 1200 rpm.
When doing the test, I found that ECT rpms were almost spot on from when I had a MT Tacoma. To maintain 45mph on flat to slightly rolling, it was 1200 rpm in normal and 2000 rpm in ECT mode. The difference? Fuel demand. In normal mode, you give her the beans and it immediately upshifts then downshifts. In ECT, not as much skinny pedal and it does not shift.
So, bottom line. You don't lose mpg and you gain less shifts.
BTW, on two tanks of fuel over the same route of city driving, the hand calculations were within a tenth of each other for 19.5 mpg.

 

a few years back i did a 35 mile run with ECT on and the exact same route back with ECT off. almost no difference in gas consumption.

 

On the freeway I either drive in S Mode or Click on ECT power, especially in hilly areas. Even with a tune.

 

i get better mpgs driving 40-45 mph around backroads in ect. it shifts less often, and stays in the powerband. I also get better MPGs in s4 compared to D on the same route.

 

I didn't figure this would be a popular thread. However, it's factional.

 

i guess we need more data

 

I'll agree on less shifts, but my truck shifts, and drives exactly like my 4.7 tundra did except for more overdrive, and never hunts as a buddies use to. That gets me 23.2 mpg all summer long. Ect sucks gas big time. When i tried it with my 2k lb boat, my gas gauge dropped pretty quick. I took ect off, and slipped it in S5 where i finished the trip around 19 mpg. Ect changes the engine sound in my truck making it louder with stupid long shift points. I can't understand why its there my tundra didn't have it. This truck has decent low end, not quite as much as my tundra, but its very acceptable. I've ridden in another v6 auto my buddy had and it wasn't the same truck as mine. I've talked to a water company employee i know well that drives their company tacoma v6 sr's...they've been happy with them, but like the ford rangers to they have. I guess if your towing 5k lb trailers, or more all day, ect probably is good to have, but for light duty, or unloaded its just not needed.

 

I turn ECT on every time I start my truck. It seems to have a tad more power and have noticed zero difference in fuel mileage.

I left it on all the time in my 1st gen as well.

 

I get the best fuel mileage in the D mode. I use s5 when towing my stuff to get the best performance and fuel mileage. If i leave it in S4 fuel economy drops...my truck needs another gear, its pulling too many rpm for the speed i'm trying to go which is 45-55 on these back road highways. Feels like i'm in low gear all the time when in s4. I only use it when going down long steep grades to save on the brakes.

 

The fuel efficiency difference between ECT on and ECT off on the 3.5L V6 is probably not very much. At very low rpm, the 3.5L relies on port injection, while starting at about 1600 rpm, it starts relying exclusively on direct injection. At higher RPM, you have more pumping losses, but the direct injection technology adds thermal efficiency to the equation to balance things out more or less. Just above the DI threshold, the motor will be working harder, but it will be more efficient at doing work. Just below that threshold, it won't have to work as hard, but it will be less efficient at doing work, so they cancel out for the most part.

The advantage of the higher gears is when you're going downhill and the proportion of the amount of power the engine makes going to the wheels vs. going to pumping air and exhaust becomes very small. Think about it, when you coast downhill with no accelerator, you lose more momentum in S4 than S6, and even more in S2. In that scenario, engine drag is 100% of the equation. Add a tiny amount of accelerator and engine drag is still the dominant variable, but it is making some power now. Add a moderate amount of accelerator, and eventually the drag of the engine (which is linearly correlated with engine speed) will be overtaken as a concern by the thermal efficiency of power production (which is not linearly correlated with engine speed).

All of that just means when you're making a decent amount of power, engine speed doesn't contribute as much to overall efficiency, especially when direct injection is involved which complicates things by exacerbating the nonlinear correlation of thermal efficiency to engine speed. That should explain your findings in statistically insignificant differences between ECT on and ECT off efficiency.

My 2.7L on the other hand lacks direct injection, so I can see on my scangauge a huge difference between ECT on and ECT off.

 

I think the butt dyno tells people that they get an extra 50HP whenever they push the button and see an LED light; its science

 

I ran month long tests on my 2017 back when I had it. In those days, ECT was actually 1-2mpg better on the tank average. The transmission algorithms on the early 3rd gen trucks sucked.

 

I haven’t tested ECT yet on my 2022, but I can vouch for the statement above regarding the early 3rd gen transmissions. My 2017 just seemed off—especially on the freeway. It would shift at strange times, and feel like I didn’t have adequate power. The 2022 seems light years better.

 

Exactly this, is my experience with ECT on.

 

I can tell no difference between 2017 and 2022. Same old constant shifting on the highway. Around town it settles around 1100 rpm as well, which I've never seen any other vehicle do. As soon as tiny little bit of gas is applied, it has to downshift. Love everything else about the Tacoma but the powertrain combo (programming) is pretty awful compared to basically every competitor in the class.

 

Never owned a early 3rd gen tacoma. This my first one coming from a 4.7 tundra. Was really surprised how much power this 3.5 v6 puts out. I think if a buddy had the same in his 2019 trd he would have kept it. His truck you could say always shifted wonky till the time hew traded it in. Power seemed down also. When i was speaking to the dealer what i wanted he had mentioned they could get 2 identical 2019 leftover tacoma's in black very similar to what i wanted, then advised me to stay with ordering your 2020....saying it had more improvements and would be worth more down the road which made sense. Idk what toyota did to improve the 2020 performance wise, but there definitely is a difference from what a buddy had even after they did the latest tsb tune on his.

 

My 2020 truck operates a little higher than 1100 around town...thats barely above idle. Its more like 1200-2k depending what streets i'm driving on. It will downshift spot on, and hold till what feels normal for conditions before upshifting.

 

here ya go

https://www.youtube.com/watch?v=Qe-4q0MGQak

 

what differences are you seeing with the 2.7? does timing advance change? air/fuel ratio? it feels like when i hit a little over 3k rpms i get a massive surge in power.

 

it is annoying that everytime you want to accelerate it has to immediately downshift. like there's always a delay in the power delivery. ECT helps minimize that but it's absolutely dumb that the default mode does that.