40+ MPG Tank in my Highlander Hybrid 4WD - GreenHybrid

Mr. Kite · #1 (**permalink**) 08-31-2007, 09:50 PM

The tank I finished last week was a personal best of mine.

According to the display, it was 40.9 mpg over 711 miles. However, according to my odometer calibrations, this is actually 735 miles. Using 735 miles and the amount of gas added, it calculated to 41.6 mpg. Over the course of all my fillups, my fuel economy using the calibration factor on the odometer is almost exactly the same as the lifetime display fuel economy. So, I believe 40.9 mpg is more accurate and my higher calculated number is just from first click variations.

Anyway, this tank was all suburban driving from August 1 to August 23. Weather was very nice and the driving was almost all mine. The only other driver on this tank was Chuck (Delta Flyer) for about 10 miles. I only drove the HiHy when my wife and I both needed vehicles, otherwise, I drove the HCH II.

One funny thing to note, now by best tank in the Highlander is better than my worst tank in my HCH II. On a tank in the HCH II driven from January 11 to February 1, 2007, we only managed 39.2 mpg over 393 miles. Of course, it is worth mentioning that it was one of the snowiest and coldest January's in Denver's recorded history.

Pravus Prime · #2 (**permalink**) 08-31-2007, 11:41 PM

Congrats!! Welcome to the over 40 MPG SUV club.

Glad to see you finally did it, I know you were working at it for a while now.

WebG · #3 (**permalink**) 09-01-2007, 06:20 AM

You said "Over the course of all my fillups, my fuel economy using the calibration factor on the odometer is almost exactly the same as the lifetime display fuel economy."

There's a lifetime fuel economy display? The one on the nav can be reset (obviously), but I am not aware that there is a lifetime display on the nav screen in addition to the resettable one. Ditto the dash display -- I thought that one reset when the nav resets (perhaps I'll double-check when I fillup today, but I'm pretty sure that the two are tied together on my HH)

anyways, congrats on all that...

Mr. Kite · #4 (**permalink**) 09-01-2007, 07:55 AM

Quote:

Originally Posted by WebG

You said "Over the course of all my fillups, my fuel economy using the calibration factor on the odometer is almost exactly the same as the lifetime display fuel economy."

There's a lifetime fuel economy display? The one on the nav can be reset (obviously), but I am not aware that there is a lifetime display on the nav screen in addition to the resettable one. Ditto the dash display -- I thought that one reset when the nav resets (perhaps I'll double-check when I fillup today, but I'm pretty sure that the two are tied together on my HH)

anyways, congrats on all that...

I should have said the lifetime fuel economy I calculated from the display fuel economy. At each fillup, I also add the display fuel economy in my spreadsheet. I take the miles driven on the tank (from the odometer without calibrating) and divide by the display fuel economy to get what I call "display gallons". The total miles driven as recorded directly from the odometer divided by the total display gallons is what I refer to as the lifetime display fuel economy.

EMO · #5 (**permalink**) 09-03-2007, 04:42 PM

So, was it hard to find an aftermarket sail and rudder for your HiHy?

Seriously, CONGRATS!

WebG · #6 (**permalink**) 09-03-2007, 08:46 PM

I just did my first real practically all-highway roadtrip in the HiHy. Average speed was 60-70MPH for two 3-hour long rides. A very little bit of mountain scenery with 7% downhill grades for a few miles, but otherwise relatively normal highway.

Computerized MPG: 30.2. Actual MPG was just about 1.5% below that in the 29.5 neighborhood (actual numbers in the spreadsheet somewhere). Used 87 octane and ran the AC, if that matters.

What I'm curious about is that my MPG on the highway is that similar to what I get when the majority of my driving is suburban. What's up with that?

PineywoodsPete · #7 (**permalink**) 09-04-2007, 12:06 AM

Although most of my HiHy driving is in the relatively flat lowlands, my best milage is always in the S. Colorado mountains - San Luis Valley region where my son lives. I always get above 30 mpg highway FE regardless of the terraine there, which I assume to be due to the decreased air resistance at this 8,000-12,000 ft altitude.

If I remember correctly, air density decreases about 3% for each 1000 ft of altitude - roughly 20-30% less air resistance at equivalent speeds at the above altitude range compared to sea level. I note that Sr. Kite hails from CO.

Pete

Mr. Kite · #8 (**permalink**) 09-04-2007, 07:06 AM

Quote:

Originally Posted by PineywoodsPete

Although most of my HiHy driving is in the relatively flat lowlands, my best milage is always in the S. Colorado mountains - San Luis Valley region where my son lives. I always get above 30 mpg highway FE regardless of the terraine there, which I assume to be due to the decreased air resistance at this 8,000-12,000 ft altitude.

If I remember correctly, air density decreases about 3% for each 1000 ft of altitude - roughly 20-30% less air resistance at equivalent speeds at the above altitude range compared to sea level. I note that Sr. Kite hails from CO.

This entire tank was driven in a relatively tight elevation range around 5,200 ft. Also, I barely got up to highway speeds on this tank. A very high percentage of my driving was below 40 miles per hour. I don't believe the air resistance plays a big role at these speeds.

If you look at my tanks in the database, you can see what I get under other driving conditions.

andybl · #9 (**permalink**) 09-11-2007, 12:43 PM

What weight and brand of oil are you using ?

Mr. Kite · #10 (**permalink**) 09-11-2007, 02:27 PM

Quote:

Originally Posted by andybl

What weight and brand of oil are you using ?

I changed the oil about halfway through this tank (at 5,000 miles), replacing the original oil with Mobil 1 5W-20.