ECT Power button disables Atkinson Cycle ? I think so

I activate "ECT Power" and Manuel Shift mode all the time because I don't like how sluggish and shift happy the engine/auto is when in "regular" mode. Other then the ECT Power raising and holding shift points of the trans I have suspected it disabled (or reduced) the Atkinson cycle because engine is more responsive and I may have confirmed that today. On flat interstate running 65 mph, no wind, no "cruise control" I was in 6th gear w/ECT Power activated and watching the MPG bar on screen between tach and speedo. When I deactivated the ECT Power, the mpg jumped up and I could feel and hear a slight change in the engine which then had that sluggish feel to it. I reactivated the ECT Power and mpg dropped back down and heard the slight change and feel again.

Only makes sense, in a normally aspirated engine, less fuel is less power. I really like my Tacoma, but 6th gear is almost useless at higher speeds, 75+, because engine doesn't have enough torque to pull 6th gear. Speed limit here in S Dakota is 80 and is easy to maintain in 6th gear in my Vette, but not in my Tacoma.

 

this has been my theory for some time... however the only way you will know for sure is to hack the ECU. Maybe toggling ECT while stopped and having someone place their hands over the cam sprocket motor would tell us more.

 

"With this drive mode select system, the driver can allow the vehicle to launch the ECT PWR mode
through a switching operation.

The ECM improves acceleration performance and responsiveness by controlling the engine output and
by changing the shift point of the transmission, thus achieving a sporty drive."

I doubt there's much beyond shift management and throttle response.

 

One way to test the throttle theory. Put the transmission in 1st (S1)and see how responsive the throttle is with ETC and ETC off. If there is a difference, then fuel mapping is also changing. If not, then it is probably how the AT shifts.

I have the 4cylinder, and of course no Atkison and the behavior is like what you have described.

Keep in mind the ECU won't let you ping the engine with the anti-knock adjustments. This means in normal AT mode, it retards the timing when you step on the gas giving you that sluggish feeling. When the engine load is lower, the timing is set better. This means in ETC mode you are loading down the engine less resulting in more power because you are not getting into the ECU retarding the timing.

 

Yes, Lots of good info after you wade thru all the worthless info and trolls. I just "ignored" lobster also and have some others on the list.

 

We laughed when we got in the new Taco's and saw the ECT button. Some Lexus SUV's have it but I always associated that button to really slow old Toyotas like the 3rd gen 4runners. I'm still surprised they didn't call it "sport" or "tow/haul"

Back when I was a young punk "race mode" used to be A/C off, ECT on and O/D off haha.

 

You guys are helping me with my list,

 

The reason I think ECT changes more than just transmission shift points is that without it, the engine seems to produce more braking. I've been playing with this and it's definitely more than throttle response UNLESS the transmission is doing something I don't understand. Once ECT is on, the truck just rolls more freely with or without throttle. I almost hate to turn it off, but I'm getting shit MPG even in D with it off (I average 18 on the highway, FML).

Something my friend brought up... the same engine is rated for higher horsepower in the other models that it's used in. I'm assuming internals are the same, so that would mean a different tune. Maybe ECT modifies the tune on the fly a bit? I'd be curious about dyno outputs with it on and off, but the real test would be to monitor the ECU of course.

 

I thought the ECT Power only controlled the trans until I watched the MPG jump up and down today so it is definitely controlling the engine tune also. Gas is cheap so not so concerned about the MPG, but I do like it to drive w/o engine laboring at low rpms and then start downshifting excessively. I read on another post that Toyota is working on a trans recalibration due to the shifting, and if so, I would get it.

 

Yeah, I've been hearing the "Toyota will update the transmission firmware" story for a few months, I'm not really betting on that. I'm with you on the engine tuning, though, it'd make sense honestly.

For what it's worth, the freeway entrance I take each morning is a marge from about 2 miles of gradual uphill road. In D with ECT off, I may as well be walking onto the highway, the truck just can't get up to speed without me mashing the gas pedal to hell. Throw it in ECT mode, life gets better. Put it in "S" with ECT on and rev the snot out of it, hitting 7K RPM this morning... and I'm at 80mph in a flash. I have NO complaints.

 

Yes, it's like a different truck using the ECT Power but do wish it had more torque.

Metalnut, thanks for the logical replies.

 

The ECT has nothing to do with the motor it is a Transmission control that allows the transmission to wind out 500 RPM more in each gear when it is "ON" The Atkinson Cyl Engine Has two Connecting rods per Piston and the Cam Shaft is ground onto the Crank Shaft

 

Is this actually how these engines run? If so.. mind blown

 

This theory sucks, thought we already established that. I posted the Toyota published explanation that the ECT works with the transmission controller and has nothing to do with the engine, but yet people insist on arguing.

 

You've been in the Boiled water to long Lobster, this is exactly how the Atkinson Cycle engine works and the efficiency derived from it is achieved by allowing all 4 Stroke events of a 4 cycle engine to occur in 1 rotation of the crankshaft eliminates the need for an independent cam shaft and cuts th intake stroke in half of what it is in a true 4 stroker. This same motor has been used in the Lexus GS350 for the past 5 years and has a proven reliability record. If you can prove otherwise please post the proof.

 

That may be how a "true" Atkinson engine is, but that is not how the Toyota version of it works. Toyota simply delays the closing of the intake valve in order to reduce the effective intake volume in relation to the exhaust stroke. If doesn't have all of that monkey-motion going on in the crankcase.

 

same thing I've always read.

 

Not arguing, theorizing. Trying to explain and understand the perceived feeling of different engine performance and apparently different indicated fuel economy. Questioning something is part of human nature, and published explanations can sometimes be purposely misleading. Not saying that's the case here, but it's an interesting discussion.

 

Dude... Jesus Christ... the lack of clear communication and mis-information on this forum is scary at times. This engine is a simulated Atkinson cycle engine... pretty sure it's ALL in the intake valve timing. 100% otto cycle under higher loads / WOT

 

I thought ECT power locks out 6th gear?