packman12

I am getting about 30 MPG on my non-hybrid ES. My driving is about 75% highway. Wondering how others are doing on gas mileage? This is my actual calculation, not the gauge estimate. I've only filled up three times and the estimated mileage has varied by 1-2 MPG, both higher and lower than actual. Perhaps that is caused by when the auto stop occurs at the pump.

I was also wondering if the Eco mode really changes the mileage. I've tried Eco in the city and I don't like it as it makes the car a little sluggish. Does the Eco mode improve highway mileage, since I think that mode just changes the transmission shift patterns? On the rural highway, the car is just in top gear at steady speed, right?

Thanks for the input.

lesz

I think you have that right. Any benefits from the ECO mode are likely to happen when you are doing lots of stop and go driving and the transmission is shifting more frequently. When you are doing highway driving or driving on a rural country road, for the most part, once you get up to speed, the transmission will be staying in the highest gear, and any improvements in fuel economy are likely to be quite minimal.

Tootsall

I'm not certain but I suspect that Eco mode also cuts out the a/c when the engine is loaded up (low manifold vacuum). One thing I mean to check the next time I'm "allowed" to go through the Rockies with their long up-hill climbs to visit family on Vancouver Island. Sport mode may do the same to get the extra bit of hp.

dklanecky1

When ECO mode is engaged, it definitely reduces the air conditioning performance. I can feel the difference (usually in higher humidity feel) in a few minutes, especially if switching back and forth on a highway drive for instance.

lesz

The following is copied and pasted from the manual for the Generation 6 ES. I'm virtually certain that the same is true for the Generation 7 ES:

"Operation of the air conditioning system in Eco drive mode
● In the Eco drive mode, the air conditioning system is controlled as follows to prioritize
fuel efficiency
• Engine speed and compressor operation controlled to restrict heating/cooling
capacity
• Fan speed restricted when automatic mode is selected
● To improve air conditioning performance, perform the following operations
• Adjust the fan speed
• Turn off Eco drive mode"

AllinCLE

I'm averaging a 29.1 MPG so far, and that's over 15,400 miles. A long time ago I built a template I've used for all my cars since. It makes it really easy for me track each fill up I've done since I bought the car new. Comparing to the computer in the car, I'd say the car is regularly optimistic by 1-2 MPG.

I'd say most of my miles are highway miles, probably 65%-70% and usually I have the car in "ECO" mode. When pointing out the obvious ECO mode changes, shift pattern and throttle response, people often overlook a more subtle, behind the scenes type change...and one that is applicable on the highway! The engines in these cars have the ability to seamlessly switch between two operating cycles: the normal Otto cycle and the Atkinson cycle. Otto is most common, and makes more power but uses more fuel. Atkinson cycle uses less fuel, and as a consequence produces less power. Part of the ECO programming uses different parameters to keep the engine running the Atkinson more often. Cruising on the highway demands little power and as such is a completely behind the scenes way to bank some efficiency savings. Especially considering on the highway there is little to no difference in "feel" between ECO and Normal modes.

AllinCLE

Tootsall

A sophisticated strategy for fuel saving but only true for the 4 cyl. in the hybrid...

AllinCLE

The dealership's marketing material you're quoting does not at all contradict what I described. They're saying the difference between the ES350 and the ES300h is the powertrain (V6 vs I4 hybrid). The fact that they used the descriptor "Atkinson" for the hybrid's 4cyl engine says nothing about the capabilities of the ES350's V6....nor should it. It's a non-technical document to help non-technical salespeople sell a car to mostly non-technical customers. It's not supposed to get in depth or be definitive in nature, but since I like this stuff I'm happy to dive in

The 7th generation ES350 uses the 2GR-FKS V6 engine, which was originally introduced in some vehicles in 2015. Even then it wasn't "all-new" but an evolution of the GR architecture (the 6th gen ES350 used the 2GR-FE, for reference). The FKS version came with a number of improvements: 1) both direct and port fuel injection, 2) integrating the exhaust manifolds into the cylinder heads with EGR cooling....and most importantly for our discussion here: VVT-iW for the intake camshafts. VVT-iW stands for Variable Valve Timing Intelligent Wide...this additional range of adjustable control on the intake valve timing is how the engine is able to switch cycles based on load demand....Otto cycle for more power, Atkinson cycle for light engine loads. And back to my point in my first post: ECO mode changes the parameters for when the engine will be in Atkinson cycle, and there are efficiency gains to be had in highway driving.

You don't have to believe me...all of this is verifiable. This old video from when the 2GR-FKS debuted may help:

E46CT

"ECO mode" is mostly software algorithm in the way of throttle mapping to *encourage* a lighter foot. It's behavior-control strategy, basically. Depending on the application the transmission logic is also changed. But generally the modes only work if you work with them and not against them. If you floor it in ECO mode, don't expect miracles. 100% throttle will always be 100% throttle.

For both my IS200t and current CT200h, ECO mode makes the gas pedal feel "heavy" cause it doesn't do much at the same pedal travel vs. in normal or sport modes. So as a result, in ECO mode, the heavy feeling pedal encourages me to not push it as much. Sport does the opposite. Response is good surprisingly, in the CT200h. In sport, hybrid battery is able to send full voltage in sport mode too at partial throttle whereas in normal modes, you only get around 500v or so, at partial throttle. Full throttle will always deliver full 600v regardless of mode. Maybe something similar is going on in gas cars too. Engineers can play tricks with software depending if you have electric assist, turbo assist, or just a plain engine.

*you* are the best eco mode though =)