We have a new 2008 Highlander Hybrid and are still trying to learn how to drive it to maximum efficiency. The Econ button certainly seems to help mileage. Should we use it only around town as the owners manual implies or can it be used on the highway , on trips, at higher speeds? The manual doesn't tell you not to use it that way. When should it be used?

Regenerative braking is not much of a factor in highway use, the ICE must run at all times anyway.

I just leave Econ mode on all the time, and haven't experienced any issues other than improved mileage and slower acceleration from a stop. In rolling bumper to bumper traffic I seem to go into EV mode more and stay in it longer with Econ on.

"When you get to the fork in the road, take it." --Yogi Berra

on a related note. Econ runs just fine. I only take it off when merging fast is needed. I was wondering if anyone knew just how much better 2008 hybrid mpg was over non hybrid. I know the epa rating but not always true. Consumer reports quoted 18 mpg overall with non and 24 overall with hybrid in their combined cycle test. That is a 33% advantage which would mean at 18000 miles per year, the non would take 1000 gallons or $4000 with the hybrid using about 730 gallons or $2900. Payback is not so long at $4 per gallons.

Regenerative breaking is a significant factor all the time - even at highway speeds.

When the battery has a high charge at highway speeds (possibly helped along by regenerative breaking) the electric motor assists the gas engine which increases instantaneous MPG.

I read something that suggesting the acceleration was more sluggish at highway speeds with econ turned on. If true, it designed to protect a driver from their own agressive driving. If a driver isn't agressive, then it shouldn't be noticable or effective. 2007 models don't have that so I can't verify or give a first hand account. Any chance someone could waste a little fuel and try punching it while already at 50/60mph both with and without econ turned on?

I agree with both DonR and wwest on regenative braking. First, remember that regerative braking is usually considered to include the power you get when decelerating (with or without brakes), which also includes the excess power recovered when coasting down a hill. Keeping that in mind, if you drive on flats with no changes in speed, wwest is correct and you will almost never see the battery adding or taking power while driving. However, when going through hills or having to change speeds, any time you need "a little extra" the EV portion kicks in a little power so the ICE doesn't have to run as hard; that energy can be recovered the next time you slow down or coast down a hill. If you read around, you will see where I talked about getting better mileage going through the hills that on the flats....wierd, but true.

Thanks for all of your replies. It is seeming to us that after more experience from driving with "Econ" that it behaves like the old "governors" that were put on cars and trucks which limited the Engine RPMS from getting too high. We are using it a good bit of the time now and it definitely helps with mileage. One place where we don't use it is for very long and steep hills on the freeway because you see a very large drop in speed resulting. Otherwise we can use it most of the time.

We are finding we are getting better mileage out of town than in town - the inverse of what the sticker showed when we bought it. That's probably because we live at the top of a steep hill and many of our in-town trips are short.