Zentropy wrote:



Here's what I do on the hiway when the traffic is moving smoothly at the speed limit:
Get up to speed as you normally would on the hiway, let's say 60 mph. Instead of p&g, which in this situation will really annoy other drivers in smoothly moving traffic, I ease off the gas pedal very slowly until I see the mpg meter hit somewhere between 40 and 60, then I freeze the pedal. In this condition, the eCVT seems to find a taller gear, and the elec motor kicks in to assist. Holding this, the elec motor will come on and off, I guess depending on whatever, I don't know. This state bleeds off speed much more slowly than a p&g, even with gentle uphill grades. I can hit this state at 65 or 70 mph, and I can keep this state for several miles until my speed bleeds down to about 55. At this point, I very slowly depress the pedal until the mpg meter hits at or just below 20. In this state, i'm using the ICE, but the HH accelerates very gradually without tanking my avg mpg. Once I'm back up to 65 mph, repeat. Using this technique, I've been able to keep my mpg above 30 so far for my current tank (I'm down to about 1/4 tank having travelled about 370 miles at 31.0 mpg avg). If I can keep this up, this will be my first 30+ tank, on the computer anyway. We'll see what my manual calc says when I fill up.

'Feathering' - BTW yours are excellent results in moderate HWY driving. In a training flyer from Toyota today ( also for customers ) they mention using moderate speeds with a dropoff in FE above 60 mph and a major drop again above 70 mph. Aerodynamics.

'Feathering' combined with P & G it does allow the driver to use the 'biofeedback' of the instantaneous mpg meter to find the sweet spot for the specific vehicle.

I've also noticed that the HH seems to have longer and easier glides than my Prius. I wonder if it's the weight of the vehicle and more momentum. The Prius seems to bleed off faster even while 'feathering the pedal'.

To the original poster:
I also think you will find better results after initial breakin and should again in the 10000 - 20000 mi range.

 

here's the thing, and i'm not 100% sure of this, but you'll note that the advertised 0-60 times specifically state that they were obtained using 93oct. i'm not sure about the 268hp but i'm guessing that was made on 93 as well. what that means is that 93 oct DOES give a hp improvement somewhere in the power curve for this particular vehicle. (i'm in agreement that higher oct does not equal better performance in most cars). the most obvious way is that the ecu is adapting to the higher octane to advance timing. all things being equal, advanced timing = more power. maybe someone w/additional info can clarify...

*EDIT - the specs on the manual do state that the hp (208) & tq (212) were obtained using the 'recommended 93 oct & that performance figures will decrease with a lesser oct. so 'performance' in this context most definitely refers to 'power'.

 

My personal experience is that the HiHy has more horsepower when I use 89 octane instead of 87, most noticeable between the speeds of 20-50 mph. The engine noise from the ICE is louder and there's less "punch" with 87. I believe the fuel savings comes indirectly. To get the same level of acceleration with 87 as 89, you have to drive the ICE harder, consuming more gas to achieve the same cruising speed in roughly the same amount of time... I haven't tried 91 octain because I'm satisfied with the power I'm currently getting with the 89 octane.

 

gang
i agree with Han on that one. I hardly ever open her up as i try to keep it level, but when i need the power to get around some folks, it does seem to respond better. I should try the 91 octane and see if that improves it even more.

cheers

 

Tom,

Thanks (in advanced) if you try out the 91 octane. I'm curious to see how much more oompf it will provide over the 89 octane. It may take a couple of tanks to make sure the HiHy electronics have adjusted to the higher octane level... If it also happens to provide a higher FE, that would be icing on the cake. You could make a general recommendation and perhaps get the general real-world FE numbers higher for the HiHy... The vehicle was designed to make use of that 91 octane.

The amount of FE improvement to justify the higher price in fuel is actually quite modest. If you churn the crank on the calculations, you can break-even if

FE1/FE2 = 2 - PG2/PG1

where FE2 and PG2 are the fuel economy and price per gallon for 91 octane and
FE1 and PG1 are the fuel economy and price per gallon for 89 octane.

We can simplify this even further and solve for the % increase in fuel economy required to break even:

%FE_increase = (FE2 - FE1)/FE1 = (PG2 - PG1)/(2*PG1 - PG2)

So, plugging in local numbers: PG1 = $3.21/gallon (89 octane), PG2 = $3.31/gallon (91 octane) this produces:

%FE_increase = 3.2%

So if our base FE is 25 mpg, then a 3.2% increase means that the FE must increase to 25.8 mpg to break even on the additional cost of 91 octane over 89 octane...

 

ok dude

I am in. But the highlander is really my wifes car. I just get to pay for it -LOL. She needs about 3 months to go thru a tank, unless we make the trek up to orlando. But when we need to fill up again, we will use 91 octane. I will report how the car performed, the acceleration, and the small diff in FE -if any. I bet it will enhance to performance of the engine, not FE.

cheers