This morning the price of unleaded regular 87 octane fuel is $3.399 a gallon at the convenience store across the street from our business. Over the next few weeks I am going to try a few experiments to improve fuel mileage. Hopefully we can all benefit.
The test vehicle is my 2001 Ford Ranger 4×4 with a 4.0 engine and automatic transmission. It has 138,000 miles. The truck is in overall good shape. A used engine was installed recently. The Ranger has good tires and a new exhaust. It gets terrible fuel mileage. Mileage ranges from about 14 MPG local driving and as high as 20 MPG during freeway driving.
I am not going to go overboard with scientific testing methods but I will try to keep the experiments valid. I will be using local driving as the basis for the tests. I am using the same fuel station each fill up and hopefully the same pump. I will be using unleaded regular 87 octane. The automatic fuel pump shut off will serve as our full indicator. Each portion of the test will be duplicated and I will refill at about 100 miles or so using the trip-meter as the mileage indicator.
The first portion of the test will be to confirm current fuel mileage. For the second portion I will be installing a Summit Racing high flow rewashable air filter in place of the original style paper filter. The air filter cost is $44.95. I will also be installing a Tornado vortex device that installs in the engines air inlet tube. The Tornado cost is $64.95. The Tornado swirls the air entering the engine that the makers claim to improve mileage by up to 15% and also improve performance. Both of these items should only take about 10 minutes to install. In addition I will be changing the engine oil to Mobil Synthetic. The third portion of the test will be the installation of a cold air intake kit that claims to improve horsepower and mileage. I may follow that up with a high flow exhaust system also. Look for follow up postings in about a week. Wish me luck.
We have our baseline mileage. Both tests were suburban driving with little or no freeway time. I did not use air conditioning very much except for a short freeway stint and anytime defrost is on because it’s an automatic function when in defrost mode. The weather has been mild. I recorded temperatures at fill ups in the high 60’s. On my first test I drove 124.6 miles. I topped off the fuel adding 7.085 gallons yielding 17.58 MPG. My second test I drove 127.5 miles and topped off the fuel adding 7.375 gallons yielding 17.28 MPG. Averaging the two tests shows 17.43 MPG. This is a nice surprise and higher than I had recorded in the past with the old motor. I am not going to worry about where and why those improvements came from. What I am watching is improvement after we make changes. Today I am going to install the air filter, Tornado device and change the engine oil to Mobil Synthetic 10W30. I will keep you up to date.
Bad news! My fuel mileage went down. One important change is that the weather turned cooler. Morning temps are starting in the high 40’s. The truck’s PCM is definitely enrichening the fuel mixture during cold start-ups. I don’t have any faith in the Tornado vortex device. My past research on similar devices showed poor results. I don’t believe there is any problem with the high flow air filter or synthetic oil. Both have proven effective in testing elsewhere. I even ran 3 tests instead of the normal 2. The average for the 3 tests was 17.3 MPG. I am going to remove the vortex device and retest. Crossing my fingers!
Now I am confused. After removing the Tornado device fuel mileage dropped a touch. I ran 3 tests averaging 16.97 MPG. I would like to perform the baseline testing again and do more testing under similar circumstances. Ideally I would run each portion of the test 10 times. I would drop the high and low test, then average the remaining 8 tests. I would also like to be in a controlled environment like a test track and do all testing on a warm engine with ambient temps similar. I still feel that temperature is having a large effect on the results because the 3 tests range from 16.56 MPG to 18.09 MPG. Maybe the Tornado device had a positive effect after all. I need to digest the info a bit and decide on a plan of action. I will keep you up to date.
I think I need to hold up on any further testing right now. The last few mornings the Ranger has had heavy frost on the windows which takes about 5 minutes of idle time to defrost before driving. If the truck were parked in a heated garage each night testing might be more valid and useful. I think there will be some good information here if I can control the the experiments better. To my surprise I found that the biggest influence is the change from the worn out engine that broke a timing chain to the current engine. The extra 2 and 1/2 to 3 MPG is a huge relief to my wallet and a welcome change. I will keep you up to date on future testing. Thanks.