The tank I had been working on trying to see how high I could get the mpg. I had to drive slow enough to get lots of usage from the EV Mode. I had posted some pictures and my peak mpg at 1/2 tank was 64.4 mpg.

It was a back and forth fight due to the cold front that moved in. My wife griping were going to run out of gas. I filled early and the fuel was never low enough (1/8th tank) for the low fuel light to come on.

I can't say yet that the energy saver tires helped. What helped was the mostly mid 80 temperatures and humidity way down to 17% to 28%. Very little wind on most of my drives.

My final was 63.6 mpg on the mfd when I filled. Subtract about 2 mpg for calculated)

The trip mileage was at 832.4 and I wanted to take it to 860+ but the wife said, no way. She's kind of little, but sure can get loud.

I'm back now to my routine driving to town in the evenings. Maybe I can compare my least years mpg data records to see how much these Saver tires are helping out.

I drove to town and forgot the Lucas upper lubricant to add to the gas and also the camera, that's why no picture.

 

Great job!

I think the hybrid has a smaller gas tank but it seems like my low fuel light turns on at 13.5-14 gallons. I've driven approximately 120 miles after the light and still only filled up a little over 16 gallons out of the supposed 18.5 gallons in my car.

The 20+ MPG difference in our cars is simply astounding; granted, our commutes are pretty different.

I wish I had a hybrid...

 

The Camry hybrid has a 17.1 gallon tank on the 2007 model. I have only seen the low fuel light come on once. The fuel gauge was between the 1/4 mark and empty. I'm with you on the gallons left when it comes on. I think I could have driven about 100 miles more.

I did drive about 35 miles more when the light was on that first time. I doubt I will go for the high mileage like that again. I rather fill up at 1/4 tank.

No doubt you would enjoy a Camry Hybrid. The 2011 comes out next year maybe by Spring. It suppose to have some changes. I wish they would be able to include the lithium batteries for the new model.

 

Amazing!

Congrats, Jimmy !! You must have earned one or more spots in the Guinness Book of TCH Records.

Gan you give a few more details ?

I infer from your post that your fill-up ws about 13 t0 13.5 gallons. How many gallons did you buy ?

Can you say any more precisely what the position of the fuel gauge was when you filled up ?

I infer from your previous posts that you went 38 days (from Aug 18 to Sept 25) on this tank. Right?

I also see that you did not drive the car every day. Do you know how many days you did drive the car. I'm interested in this because I would like to know how many miles you typically drove the car on a day on which the car was actually used. I would also like to know how many "cold starts" you think you avoided via warm-up via use of the block heater (for this tank), and I am assuming that this would be one for every day that the car was driven. The point of my interest, here, is that I think that the best way to estimate the block heater fuel savings is via the amount of fuel saved per cold start avoided. (I have my own observations in the temperature range typical of your summer, but more on that, later.)

I would also love to hear your thoughts as to why fuel consumption should be better at low humidity. I am recalling that there used to be devices which touted fuel savings via water injection. Counter-intuitive ?

 

Close on your gallons estimate. It came out to 13.667 gallons when it auto shut off at the nozzle. I never fill any more than the single shutoff. That's another reason I try to find a top tier gas station with a level drive. That would have left me with 3.4 gallons to drive on. I might have gone another 200 miles (@ 60 mpg) if I could took it down to dry. I rather not risk running out of gas and is why I usually fill at 1/4 tank.

My final mfd read 63.6 mpg at 832.4 miles. I usually don't do calculated but I did on this tank. The 13.667 gallons came out to 60.90 mpg. This time the calculated was 2.6 mpg lower than the mfd reading.

I forget the total driving days. This tank was about 10 to 12 more days than my usual routine driving to town. I drove it only when the driving weather was very good. Temps in the mid 80's, wind 5 mph or less. The humidity was the tough one, I would wait till the humidity was between 17% and 29% before driving. I parked it on days when it was raining or high winds.

I did find doing the higher mpg test that the low humidity seems help. The ev mode seems to stay on longer and comes on more often. When the humidity is low it seems to help the engine to be more efficient.

Yesterday I pulled out on the 4-lane highway headed to town. I slowly accelerated up to 40 mph then put on the cruise. It went right into the ev mode for a full 2 miles. Along that area it's very rare for it to go into the ev mode other than 10 or 15 seconds.

When we got home I checked my small wx station history. The humidity was down to 17% when we left for town at 6 pm. That must have been the reason it was performing so well.

My usual tank runs from 23 days and sometimes to 28 days. They are a few days a month we don't go to town. It's usually a few days short of a tank a month. Normally I drive about 32.6 miles each day to town and back.

Yes, I did use the block heater 1 1/2 to 2 hours before driving the car on this test. I wanted to do everything possible to achieve my highest mpg reading so far. The best time to do a test like that is during the Spring so it's warm but not enough to run the air conditioner. As you know the block heater is more for winter use.

I remember war planes using water injection to increase horsepower in WW II. I do know it quickly turns to a hot steam as soon as it gets into the hot intake manifold. It may help cool the combustion somewhat.

I did read years ago on auto engines that the water and hot steam deteriorates the spark plugs. When the first no-lead gas came out in the early '70s it would collect a white residue on the tops of the slightly cupped pistons. Pinging on any acceleration and the engine would detonate and run after you turned off the key. This was when using a quality gas and the timing set to the factory settings. A easy fix was to pour water down the warmed up engine while revving it. That would blow the residue out the tailpipe. Back then GM recommended if you did the piston 'steam clean', be sure to change the oil and install new spark plugs. I found also using slightly colder spark plugs helped with the detonation problem. A year or so later the gas companies came up with a much improved formulated gasoline. This could be from the many auto manufactures and customers complaints. If I remember correctly the government was the main pressure for the gas companies to fix their poor gas problems.

I found this to be very interesting information..
http://www.gasstations.com/betterMilage.asp

here is your water injection answer..
http://www.cadillacforums.com/forums...m/t-18153.html

I will include two earlier thumbnails below, the one without the low fuel warning was almost to where it was when I filled up yesterday. I was at a 1/8th tank on a level drive. I was expecting it to come on at any time.

The picture with the high mileage and low fuel light. The light did came on at 1/8th tank. This was on the 59.5 previous tank when using the oem tires.

 

Somebody sent me this neat little auto question game, thanks.

http://www.cramersweeney.com/brandprix/

 

Jimmy,

Thanks for the info.

I'm concluding that if you were single, you probably would have gone 1000 miles.

I have also have a wife with the out-of-gas phobia. She sees your wife's side of it completely.

I, on the other hand can only see the missed opportunity for a 1000-mile tank.

For what it's worth, my own observations with the block heater indicate a savings of approximately 0.02 gallons (summer) to 0.04 gallons (winter) in Houston per cold start avoided. I have lots of observations of about one ounce of gas saved per cold start avoided in temperatures of approximately 80 F.

So, I figure that your-once-per-trip-to-town use of the block heater might have saved you about a gallon of fuel on that last tank based on 30 days of use or 3/4 of a gallon based on 24 or 25 days.

I would encourage you to keep on using the heater even in the hottest summer weather and even when you are not going for a max miles tank. There are real fuel savings to be had no matter how hot the weather. True, the potential savings are less than in the winter, but you might not need to plug in quite as long to get fully heated up, so the electric cost could be lower as well.

A suggestion: If you try to go for another max fuel tank, try plugging in long enough to actually get the temperature gauge all the way up to the normal operating temperature. My data would indicate that this might require a little longer plug-in tome than you use and also that the best fuel savings require this.

You could easily do your own tests to determine the savings per cold start avoided to verify my conclusions for yourself - and for your own car and your specific conditions and temperatures. (I could post or PM my protocol, but if you have a scan gauge, you might be able to work out a more accurate test than I use.)

I can plug in at the office as well as at home, so I can sometimes save a couple of gallons a month, and since I usually use only 10 or 12 gallons a month, anyway; so that's a significant % savings for me.

 

I have found to get the max usage from the block heater, is to plug it in 2 hours early in the summer. Three hours works best for me during the winter. My guess is 3 to 4 hours if the temperature is 5 to 25F degrees.

During the winter I haven't been able to achieve a normal operating temperature. Usually 1/4 scale but driving with the engine, it warms up within a 1/4 mile. In the summer it will reach normal temp while it's sitting in the drive way.

I understand the Prius block heater is 400 watts. The Camry Hybrid heater could be similar but maybe more like 500 watts.

 

On another TCH forum, a member stated the block heater draws 434 watts ... so is probably about the same one as the Prius.