At the right speed, the tailgate actually causes a ball of turbulence to form in the bed. Once the turbulence forms, it acts like a shell, allowing most of the air to pass over the bed. There was an episode of Myth Busters on trucks and they had a toy truck in a water tank and bits in the bed of the truck to let you see the current. Until I saw that, I thought the same thing. Lowering or removing the tailgate removes the turbulence ball and creates a larger vacuum area behind the truck cab.

 

Most battery chemistries, including our NiMH, are less efficient when colder. Our batteries are vented from the cabin, and should reach close to cabin temp (plus a bit more warmth from internally generated heat) about as quickly as the cabin temp itself stabilizes. However, we tend to keep our cabins cooler in the winter and warmer in the summer, with both well in the "comfort" zone of these batteries.
Nothing like empirical data. Seems like the optimum speed is near 45. Thanks!
Cold air is denser. Has more O2, which should make the engine more efficient, but while that can allow for greater peak power, it is fully compensated for by the throttle and injectors to have little effect on efficiency. On the other hand, denser air has greater drag on the car, and that is probably the main reason milage drops in cold weather (after accounting for terrible MPG during engine warm up). I would love for you to repeat your ScanGauge tests next summer and see if that raises the optimized MPG speed any. (I'm guessing it will only go up a couple MPH, and still be under the 50 I was guessing before.)

-- Alan

 

I will pass this information on to my wife. She is against driving around with the tailgate down or using the webbing type tailgate replacement to allow the air to flow tough. I somehow missed that episode on Myth Busters.

 

I bought a new 2003 Corolla and it was broke in as we headed on a 650 miles trip back to Garland, Texas to visit my cousins where we used to live. We left out at dusk. I had a scan gauge on this car. The mpg highway was usually around 40 mpg in normal weather. It kept getting colder and colder as we headed east in Interstate-40. I just could not believe my gas mileage was falling down to 25 then to 22 and finally 18 mpg. I tried slowing down which helped very little. I was driving about 50 due to the visibility and snow was coming down which got heavier as we drove.

My theory at the time was this is a very lean burn engine. The cold weather was cooling off the all aluminium engine so fast it kept running richer to keep itself warmer. I kept looking at the outside temp and my 18 mpg was the same as the outside temp at 18 degrees.

I forget what my calculated mpg was which was a long time ago. I had driven the '07 TCH to town when it was in the 20's and don't remember seeing any low mpg like compared to the '03 Corolla. It was a super great city car but on the highways it sat up rather high and the near sports suspension was a little to much for me and my wife due to us being older. The XLE Camry hybrid answered it all, top mpg, nice quiet ride and etc.

My guess is your Lexus ES hybrid will be quieter than the new Camry with the help of it's larger tire size.

 

It was several years ago and they may have even done a full scale test.

 

How do you use the Scangauge to help you improve your FE?

 

From Midland also. I skied there in the early '90s. Spectacular view of the desert and Trinity test site from the summit. Too many beer-logged Texans, though.

 

I bought the scan gauge II back when that version came out with the larger readout scale. I used it on the '07 TCH I had with the gauge set to default. I did have to set the fuel to, hybrid so it would stay on when the engine would shut off while driving.

I found by setting it to default it would then show the mpg reading 4 to 5 mpg higher on a full tank. This way I could determine which constant speed with the engine would give me the best mpg. It's like engine, vs friction vs air drag on the front of the car. I came up with something like 44 mph.

The scan gauge also had a LOD or engine and EV mode load. This helped me read the load on the engine or I think when in the EV mode. I found driving in EV at 40 used up the traction battery charge quicker. The car would drive much farther at 35 mph. Even father at 30 or 25 mph.

When we turn off the 4-lane 8 miles south of Alamogordo, NM where we live to a small paved country road. I can drive at 20 mph the 2 miles to the house all in the EV mode. It's a little harder to do in the winter but summer it's easy to do. In fact during the summer the traction battery will have enough charge left to get me 1/2 mile back toward the highway the next day.

I traded my '07 TCH for the new '12 TCH XLE loaded. I still use the scan gauge at times on my new TCH for gallons per minute, air cleaner intake temperature, engine coolant temperature. It will show you the throttle position and MAP reading. MAP or manifold absolute pressure sensor which the ECU gets it's information from to tell the injectors how much fuel and how much ignition timing to use for each cylinder for best combustion.

For the engine and EV load I use the oem ECO meter that's now on the '12 TCH in the left side of the speedometer. It's easy to read being analog and I can now see exactly where the engine will come on from throttle pressure when you driving up a overpass in EV. It's great for someone like me who works to get the highest mpg possible.

I used the velcro strips that came with the SC unit to attach it to my steering column between the steering wheel and the instrument panel. I have seen some using google images attached using a 1/8" rubber pad that had sticky glue on both sides. I may go to the rubber pads once I find were to buy them. The velcro the SC sometimes tends to tilt off center a bit.

I will tell you any baked on sticky velcro is easy to remove by using a product called Swim Ear. This is used for those that get water in their ears when washing their hair. I evaporates the water after putting in a few drops in each ear. I had a long strip of velcro on the dash of the '07 TCH where I had mounted the SC one time. I wanted to get rid of that before trading the car. I used a few drops of swim ear bought from the walmart pharmacy and let it soak for a minute or so. The velcro pulled right off and then using a lint free cloth with more velcro cleaned up any more sticky black glue that was left.

I don't know if a scan gauge would help you or not. I tell my findings using it over the 5 years I owned the '07 TCH and now near a year with the '12 TCH.
I have have better luck in the summer by driving the '12 TCH with the engine and EV mode both at 40 mph. Dangerous yes depending where you live. Not that much traffic even on the 4-lane to down is a 55 zone and in town we go around 6 pm when the workers have mostly gone home for the day. I'm very careful including my wife using her passenger side mirror to look for traffic coming up behind us. I flash the flashers usually once when I see a car or truck approaching from behind around 300 or so feet. In town I do the same when the car area in the 40 mph area were I can drive rather safely at 35. Again divided 4-lane though town makes driving for mpg rather easy.

Here is the amazon site for the SC with 377 customer reviews you may enjoy reading. I see that Autozone may also carry or order the gauge, but i'm not sure of their price. SC people have some smaller gauges I still prefer the larger screen of the SC II model. The SC allows you to show any 4 readouts on the screen at the same time which is very easy to do. I should mention the SC II can also read out any trouble or fault codes you may have and it can remove those although they may come back. It's up to you to find out what the trouble code means, SC only gives you the fault number.

 

I have not been up on the Sierra Blanca mountain (Apache Peak) near Ruidoso in the 13 years we have lived here in Alamogordo, NM. Lots of history information here in town about how in '44 when the test bomb went off people here in town said it looked like a large rising sun about 55 miles north, northwest of Alamogordo from that famous Trinity site the morning they set the bomb off. They have a tour out to see it the site twice a year from out city, but it's early in the morning and my wife has us as day sleepers now that were retired.

It amazes me that they could build the atomic bomb back in 1944. During that time the Chevy's were all inline 6-cylinder and manual shift transmissions. Ford used their flathead V8 engine also using a manual floor shift. Everybody using radios instead of televisions in those days.

I had that same felling in 1969 when Neil Armstrong set foot on the Moon. Can you imagine the slow simple computers used in that flight and it's tracking. Radio communication back then to the moon, how did they do that.

Communication and TV from the moon in '69. If I remember correctly they had just touched into testing in the very low Ghz frequencies at the time. NASA may have have used some proven secret radio equipment then designed by Collins Radio to use for this first manned moon trip.

https://www.google.com/search?hl=en&...CKjGiwKEiYHABQ

 

rburt07, thanks for the info. I have had one for use and like it, but have never really used it beyond its basic functions. I will check out some you have listed.