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What is the SippingFuel, Fuel Economy Experiment?

Here I will attempt to get the most out of my daily ride.

It is a run of the mill 2006 Toyota Corolla and bone stock at the moment.

The first "mod" I will be doing is the nut behind the wheel.
While I can not consider myself a "hypermiler" I will be altering the way I drive by slowing down some as well as not using the accelerator pedal as an on/off switch.
What you see here is the "test mule" so to speak, my daily driver with about 53k miles on it.
I have been keeping tab of the gas mileage since I have owned it and has a lifetime average of 32 mpg at the beginning of this experiment.
My daily commute is 108 miles round trip mostly hi-way.
Recently it has thrown a code causing the "check engine" light to come on and the car is shifting very hard.
Toyota will be taking care of that shortly.Otherwise I keep the car well maintained.
The EPA gives the car a 26 city 35 hi-way and 29 combined rating.

A little bit about me. For my entire life I have been an auto racing fan, still am, and I am also re-building a race car.
So I have some background in working on and with cars. Being a speed junky is not making this whole slowing down thing any easier, that is for sure.
This, needs fixing.
It certainly is not helping my mileage in the least.

This fog light hole cover disappeared one day when I was following a pickup truck and it ran over a truck tire carcass and kicked it up right in front of me.>
I was able to swerve enough to avoid a direct hit, but it just caught the passenger side of the car leaving several black marks and blowing out this cover.
I have looked into replacing it but I have found that a set of fog lights would cost about the same.
The Plan
The first thing that I have started doing involves my driving style and habits. Everything that you read about saving fuel says to SLOW DOWN.
Previous to this experiment I would be the first one leaving the line at all stop lights. Always pushing the limit as far as speed was concerned. (80 plus was not un-common).
To start off I have begun to drive at 70mph or less, keeping the engine rpm's below 3000 is the hard limit. This limit allows me to go up to 75 for short times due to traffic situations. I think that the more I try to stay at the lower speed, the less I will venture past 70.

This is actually harder then you might think. Specially on the road I travel which is opposite traffic. Going 70 mph I am one of the slower people driving out there.
I am also accelerating a lot easier then I ever have as well.
Even with the car in its current shape, check engine light and missing fog light cover, I have been able to reduce the fuel consumption.
I will be fixing the few problems, work on my driving and continue to keep track so I can see if I can do even better with the car in stock trim.
I have also pumped up the tire air pressure to about 40psi. still below the 44psi max printed on the sidewall.

Some Results
In the 5 tank fulls prior to the driving change I was able to get 33.1 mpg.
The 5 tank fulls after my driving change I have been able to get 35.8 mpg. getting a personal record of 39.1 mpg on the last tank.
That is about a 8% improvement.
Aero mods
This area of getting FE (fuel economy)seems to be pretty grassroots, mainly because I really havent seen the average Joe with a wind tunnel, which in my mind is what you would need to be absolutely posative that a change will make a difference.
Since wind tunnels are far and few in-between what people typicaly do is make a change and test out on the road.Sometimes it works, sometimes it doesnt.

What I have decided to play with first is wheel deflectors. Toyota seems to think they help so maybe I can improve some on what they have already done.
The theory behind these deflectors is to direct the air around the rolling tire where it is very turbulent and causes drag.
What you see above is what Toyota has put on the back tires. As you can see it bearly covers half of the tire, I think I can make this better, but we'll see.
This is at the front of the car
As you can see this one does not even come near the front tire.
I really do not know if the adding these wheel deflectors will help or if it even be a measurable difference.
But I figure if it doesnt hurt the mileage any I will either leave them be or change them till I see some sort of change.
But first I will be getting the check engine light and fog light hole fixed before taking on any of these changes.
I will also look into adding an air dam along with these wheel fairings. All of this to improve the aero dynamics to gain a few extra mpg's.

April 18th 2008:
The ECM has been replaced by Toyota.
The car shifts much smoother now but I do not yet know what affect this will have on FE
I will be looking into a set of fog lights to be put into the stock location filling the hole left by the truck tire.
In the mean time I have been trying to perfect my driving technique which is still a challange.
I am also looking into a ScanGauge II from This helps you know how your driving is affecting your miliage in real time.

May 8th 2008
Just a quick update to let you know that I havent given up.
The last tank of gas I got 41MPG!!!!
I just did an oil change and used a synthetic blend. Dont know what affect if any that will have but this game seems to be the sum of the whole not just many large gains.
I have also started making the front wheel air deflectors which I will be finishing soon and will show how I did them and how it all looks etc.
I am also still working on getting that hole in the front bumber filled with either a light or just another cover.
Please feel free to contact me about anything on these pages. Contact information is located at the top and bottom of each page.

May 13th 2008
The funny thing about modifying a car while you are still learning is that plans change. They change quite often and sometime quite drastically.
In my research for the air deflectors I found the following article AutoSpeed, Modifying Under-Car Airflow.
And while I am still going to go ahead with my existing plan, The design is goind to be quite different.
I was planning on some quite large deflectors that covered most of the front tire.
Now, after reading the article, I am going to cut it down to about the same size as the existing deflector but extend it across to cover as much of the tire with out extending past the outer part of the wheel well.
So it is back to the shop and my trusty band saw for me.

May 14, 2008
Inspired by the good folks on the EcoModder Forums
I made a snap decision tonight and decided to put an upper grill block on the car.
From the Back
What I used is a scrap piece of vinyl siding, securing it with some zip ties.

From the front
This is looking almost up at the grill, You really can not see it from the front or side view.
I will let you know if there is any improvement in gas mileage keeping an eye on engine temperature.
Based on a highly scientific observation (number of bugs in the radiator) I dont see much air getting thru the upper grill.
Of course this also means there may not be much improvement. We'll see.

May 29, 2008
After burning thru a few tanks of gas after installing the upper grill block. I can say that I really can not measyre an exact increase in Fuel Economy.
But, I can say that I am consistantly getting 40+ MPG. Where before the gas mileage was much more erratic from tank to tank.

June 9, 2008
I have installed the front wheel deflectors. I decided to keep the same amput of ground clearance as the original.

Looking from the front.

Looking from the side.

I am a little over half way through a tank of gas and will have to burn through a few tanks to see if this makes any differance. Taking it on its first drive with the deflectors installed, the car seems to coast slightly better, but this could be me looking for something to be better. I will know more in about two weeks, after I go through 3 to 4 tank fulls.

June 17, 2008
Well with the first full tank after installing the front wheel deflectors I got 42.7 MPG.
Which is the best tank I have gotten yet. This is encouraging but I also suspect that it may have been an short fill up, so we will have to wait it out for another tank or two.

July 29, 2008
I finnaly broke down and bought a new set of tire. i figure that 62k miles was enough for the original goodyears. I bought a set of General Tire Altimax RT tires from The Tire Rack These seem to be the best (in my mind) for an all-season tire. How they will perform as far as fuel efficiency is concerned, I'm not too sure. I guess time will tell. I will be pumping the air pressure up to 40-42 psi. The max on the sidewall is 44.
I will be reporting how they do as soon as I run through a few tank fulls. Which will take a little longer these days since I have started to car pool with one of my co-workers.

August 28, 2008
So after a several tank fulls of gas, I have come to the conclusion that the general tire Altima RT's are not all that good for FE (fuel mileage)
Since putting the tires on, I have averaged 37.6 mpg. This is about 2 mpg less the I have been averaging. Not all that good in my mind.
On the other hand, looking at them from a performance point of view.
They seem to be way better then the OEM goodyears that were on the car.
The wet traction is superb, handeling is much improved, although they are VERY noisy.

I chose them for wet and or snowy weather since I do not want to get seperate winter tires at this point in time, So I guess I should have realized they will not be the best for achieving a high amount of FE.
It could be that as they wear the FE will improve, time will tell, and I will be continuing to monitor the mileage as always.

October 7th, 2008
This past weekend I spent some time making a few small modifications to the fridge. The first thing was to add a couple of ground wires to the engine.
One I attached to the cylinder head near the fuel rail, the other to the alternator mount. This is in an effort to reduce impedance in the grounding of the electrical system.
With all of the different types of metals and gaskets, there is a resistance that builds up on the ground side of the circuit. So with the additional grounding wires this helps to alleviate this problem and ensures that things like the fuel injectors are working at the proper voltage/amperage.

The next is I added a warning light to let me know when and if the colling fan is running. This is important to know when blocking off the air going to the radiator.
You dont want the fan running all of the time for two main reasons. One if the fan is running that means your engine is too hot and will be damaged. two the fan uses electricity being generated by the alternator which in turn has to run harder which puts additional drag on the engine, hurting fuel milage.

The last thing I did was to disable the daylight running lights. Again they are drawing power from the engine and I know when and how to turn on the lights when needed.

All of these modifications will yeild very little if at all noticable increases in the fuel mileage, but every little bit will help and adds up.

October 12, 2008
This weekend I have completed a few more items on the todo list.
First is disabling the AC compressor from coming on when useing the defrost. If I need to use the de-humidifying that the AC provides I can reach over and push the button. The prosecc is quite simple and very reversable should I feel the need to go back. You can find the very easy to follow instructions here.I also added an additional aero mod. Under the front of tha car, between the radiator and front facia, is a very large gap, as you can see here. There was no need for an AC replacement compressor since the one in the car was fully operational.

Looking underneith from the side

I used a 2x3 piece of thin sheet steel and cut it to size and installed in the back using existing fasteners for some of the underbody covers, and using several sheet metal screws up front.

The first drive it seems to be different, Im just not sure how it is different. There was no difference in handling which I was slightly concerned about. I guess time will tell, and if time proves this to be a good mod, I will take it off to clean up some of the sharp edges and maybe paint it. Stay tuned for the update.

Last Update ???
Well the "experiment" is long over and the car was passed down to the kids.
I am glad to say that it has over 200,000 miles and still running fairly strong. The catalytic converter had to be replaced, but that is really the biggest issue it has had. We did just get a recall notice for the air bags, so it will be going in for that soon.