I wanted to state my real world experience with my '07 HyHi. I do not hypermile (I just don't have the patience). I pretty much drive the way I have always driven, barring some very slight changes based on being more aware of mileage. Also, I have a pretty base model AWD car/truck/whatever; no EV switch, no pretty color display, just some additional information on the middle dial of my gauge cluster.

When I am running on the freeway (between Sacramento and the Bay Area), traffic withstanding, I usually drive about 70 - 75mph. My display reads that I average about 27 mpg, and it has read as high as 29.5. Around town, and with about a 50/50 mix of street/freeway, it usually reads 22 - 24mpg. My display usually reads about 1 - 1.5 miles per gallon higher than my explicit calclulations.

I do, on rare occassions, tow a small trailer, but probably not much more than 800 or 900 pound loads from the local Home Despot. I occasionally go flyfishing and take advantage of the AWD on some pretty tame dirt roads. I commute alone, but often carry three or four passengers for most other tasks.

My mileage, and I think most would agree, doesn't match the EPA/CAFE calculations, but I didn't expect that. I do get better mileage, overall, than your Lexus non-hybrid without trying. And THAT was the biggest reason I went with a hybrid over a non-hybrid.

All of this is sort of a mixed-argument for and against WWEST. I didn't buy my car to be a replacement for a Silverado/Titan/F-250. I didn't buy my car expecting to get the same mileage as a hybrid Civic or Prius. I bought my car for the reasons most people do, I wanted a more efficient station wagon. And I think I got it.

rw

 

philmcneal -
On the way home tonight I let off of the throttle while approaching an off-ramp (seems normal enough) and watching the multi-information display noticed that the ICE was NOT running. This was at approximately 60 mph. This happened at all speeds...

I am not sure how to tell (without looking at the display) that the ICE has stopped running? ..... at 60mph it is almost impossible to hear the ICE running. Would something like the Scan Guage II show the ICE stopped (assuming the rmp indicator goes to "0")?

Has anyone had any luck with the Scan Guage II? My request for additional information from them has gone unanswered which makes me wonder about the companies customer service....

 

hm i haven't seen any cleanmpg member with a highlander hybrid with the scangauge, i do know in the prius after 64 km/hr (40 mph) the engine spins around 950 rpm but with no fuel, the electric motor is spinning it for you. Once you step on the gas pedal, the fuel and spark begin.

I don't mind that on the highway since i prefer the no lag to engine power, however, what I'm interested is once the car is warmed up and you let off your gas pedal below speeds of 34 mph then does the engine shut off assuming you did not idle with the engine for 7 seconds before it shuts off on its own?

I notice when your at a red light, as soon as you hit 0 mph the engine stops abruptly, but when the car is warmed up the engine will idle 7 seconds before shutting off. By then your in true hybrid mode, "Accelerate with the engine, and then light load cruising with the battery, but when on highway speeds then the engine just cruises. Unless your foot is totally off the gas pedal, then the engine spins but with no fuel or spark."

 

I do have a Highlander Hybrid 06 with a Scangauge.
Many members of this site have them, they may not check the site often.
The Scangauge will record the engine RPM which can indicate when the engine is on. Engine does come on over 38-40 mph but at a low rpm. Around 950-1100 rpm. Scangauge is very useful tool.

 

Thanks lensterman -
As I mentioned, I had contacted Scan Guage about the differences in the data set that is displayed between the Prius and the Highlander. They had stated that there was "expanded" data available for the Prius (SOC comes to mind). When I asked if the same expanded data set was available for the Highlander (since it is essentially the same HSD system) they went quiet and have never responded even after several attempts from me as a followup.

It seems interesting that the HSD system display doesn't show the ICE running - although - as you and philmcneal have stated - the motor will rotate at a low rmp (no gasoline / no spark) presumably so that it can immediately be called into action when needed.

I noticed this morning that the ICE had already stopped running as I approached the stop sign. . . but that still doesn't answer the question about "when" it is shutting down.

If your Scan Guage shows the rpm at 950 - 1100, do you have a fuel flow display that would support the theory that it is "free wheeling" and not consuming any gasoline?

 

yea if the hybrid system isn't warmed up fully (coolant temp at 168 F or 70 C) then that is the characteristic, however if you stop at that stop sign fully and the engine idles for 7 seconds THEN DIES then your in full hybrid mode (gas on, gas off)


we have gallons per hour or liters per hour to help aid diagnostic however my current scan gauge has a bug where it shows .004 liters per hour even though engine is completely off.

if your foot is off the pedal and you see it at 900 rpm, however the FUEL economy display on the stock screen shows 0L/100km or 99.99 mpg then its no fuel no spark but spinning however thats ONLY if the speed is above 35-40 mph (we need confirmation on this).

Under 40 mph or 35 mph it should be 0 rpm

 

I can check and see if I can confirm the engine is at idle or off with another gauge.

 

i didn't realize you read the prius stages, so my question to you is, do you have to do the stupid idle check before your fully in stage 4? or it goes immediately to stage 4 when the coolant reaches 70 degrees C or 168F?

i know the two mode hybrid does immediately when your at operating temp and y our below 30 mph, no idle check. It can Regen in N and have the engine shut on/off unlike HSD Toyota hybrids, N will override any rule and keep the engine in the state before going back to D again. (if on it stays on, if off it stays off).

That's how i would abuse the EV mode operation, i turn on EV mode and then put it in neutral and then go down the hill hehe, but the problem is when you want to Regen you slap it back to D, for the GM hybrids you can leave it in N... lucky!

 

I just added my first two tanks to the DB....and I am a little disappointed.
Tank 1: 274 miles @ 12.969 gallons = 21.13mpg
Tank 2: 320 miles @ 14.101 gallons = 22.69mpg

I know that the mileage is said to improve over time -- and as I near the first oil change it will stabilize. That being said, I expected more since my display showed 24.7 (meaning that I have a 2 mpg discrepancy between "real world" mpg and what the on-board mpg calculator shows).

Tips? Techniques? ...witch craft...? (yesterday WAS Halloween....)

...or do I need more patience...?

 

The HSD system ONLY yeilds significantly improved FE vs non-hybrids when/if FREE energy is available via frequent stop and go traffic. For "all" highway driving you'll be lucky if you can match the FE of a standard Highlander. Probably won't ever be able to match the highway FE of the upcoming I4 based Highlander.