So, I've been driving my car in ECT Power mode (I usually drive in ECT Normal mode) for the past few days to see if it makes any difference in MPG. I notice that the car jerks when braking on the freeway (note: this is REGULAR braking, not slamming on the brakes because everyone in L.A. is doing it).

I also notice the following "symptoms" :

Car has a tendency to pull forward when stepping on the gas like a turbo is kicking in.
Car revs higher.
Car jerks quite a bit more often.

I have only been driving for a few days, so I don't know if it makes any difference in MPG yet. Will update once I have that info.

Anyone else notice these symptoms? Any info is greatly appreciated. Thanks!

 

Yes I notice that also, even a tap on the gas u see ur self at 4000rpm the jerking is normal is downshifting thinking u in the corner and u will punch the gas when you getting out of corner keep us update on the mpg

 

What your noticing is exactly what the ECT PWR mode does.

Car pulls forward quicker - This is because the throttle becomes more responsive in ECT PWR (Kurtz explained once it was because the sensitivity on the gas pedal is increased)

Car revs higher - ECT PWR mode changes the shifting patterns of the car to allow for more aggressive driving. So you'll see the motor will rev higher and downshift earlier then it normally would.

Jerking - This is likely because of the more aggressive shifting pattern the car is using. If you're driving normally with the car in ECT PWR mode, you will notice it more. If you drive aggressively, you will notice it feels better in ECT PWR mode and it will feel less "jerky"

The jerking your feeling on the freeway while braking is the car downshifting so when you hit the gas again you'll be revving higher in a lower gear first.

 

So I just finished a tank of gas with ECT Power. According to my calculator, this tank did a combined average of 22.89 mpg, while my previous tank (driven in ECT Normal mode) got 22.69 mpg. My car's calculations indicates 23.2 mpg on both tanks. However, I drove on local roads MORE with this tank versus my previous tank. I'd say easily double what I usually do. I'm guessing ECT Power mode does get better MPG, but not much. Maybe if I drove on the freeway as much as I usually do, the MPG would be a bit better.

 

You're supposed to get worse mpg's with the ECT on. The engine is revving higher and potentially using more gas... not the other way around.

As far as jerking, something doesn't sound right. No IS transmission is supposed to jerk under any condition. The extra power from ECT should be subtle and gradual... I've never heard of it slamming or jerking anything. Nor does it do it for me and I've had it in ECT since day one.

 

Jerking is actually normal with ECT Power on. I experienced it with my IS350 and a loaner IS350C I had. It's doing what it's suppose to do as Killa indicated, aggressive shifts. I tend to leave it on freeway when there is no traffic. I turn it off when there is traffic b/c constant brakes = constant jerks. As far as MPG goes.. it honestly doesn't make much of a difference. I usually get 23 MPG city/highway combined with or without ECT Power. I honestly don't mind losing 1 or 2 or gaining 1 or 2 MPG as long as I can have fun with my car.

 

The jerking is a quick downshift when you tap the brakes, the car is getting ready to accelerate so it drops from 6th to 4th to be ready for you to get on it.

 

Higher rpms = more gas consumption. Your mpg is definitely gonna decrease with the ect power on

 

For me power mode is useless, tried using it for one day and discovered all it did was give me whiplash/headache...

 

From what I have noticed when breaking in ECT Power mode it seems to downshift at a higher RPM to add the extra drag from the lower gears to slow you down faster. In Normal it'll be a seemless downshift that you can't feel, in Power you'll be breaking, then all of a sudden you start slowing down alot faster then expected because of the aggressive downshifts.

I may be wrong but its what it feels like to me.

 

What ECT-Power mode actually does-

https://www.clublexus.com/forums/3305550-post10.html

The last item, Sudden Deceleration Downshift Control, is the one with the brakes.

And for those who drive around in ECT-Power and use the performance-useless paddles, note that ECT-Power does nothing if the car is in S mode.