Ask TFL: Your Tailgate Down Ram 1500 MPG Test Was Done Incorrectly – Here Is Why…

We showed an 8.5% efficiency improvement with the tailgate up (normal driving).

ram 1500 tailgate down up mpg test results

We recently got a note from Ken, who used to work on testing Dodge Ram pickup trucks in the 1970s. Ken says that our tailgate down versus up Ram 1500 MPG test was done incorrectly and hence shows invalid results. Here’s what Ken says.

Ken writes…

My name is Ken and I watch as many of your youtube videos as I can find.  Last week there was a video about “tailgate down gas mileage, the myth”.  It even referenced the Mythbuster as having tried the same test.  I’d like to tell you, both of you got it wrong.  Here is some background.  I worked for Chrysler Corp during the 1970s.  After years of having no truck sales growth, the Test Team was charged with finding out why.  It was discovered that even though truck buyers liked Dodge Trucks they didn’t like the gas mileage.  The Test Team took several Dodge Trucks, 100’s, 200’s, and 300’s to the Chelsea Michigan Test Track.  This test facility was used for vehicle tests for many Chrysler vehicles.

They used Hi-Speed cameras along with many other instruments to determine the actual mileage under real-use conditions.  They found that just like Race Horses (whose legs during a race have all 4 legs off the ground) the 1/2 ton and 3/4 ton pickup’s rear wheels were doing the same.  To resolve this problem they tested many configurations.  Without going into a long explanation of everything they did, the actual test that did show results was as follows.

Two options:  1) Open the tailgate and apply 200 pounds directly over the axle, and 2) Remove the tailgate and place 200 pounds directly over the axle.  

As I was not only a Dodge Truck owner I was also part of the Test Team and we saw real-world results.  The Mythbusters got the test wrong and so did TFLTruck.

Ken also adds some additional explanation below.

Ken writes…

Thank you for reaching out for clarification, I thought my explanation might be a little hard to understand.  I’ll try to give you all of the details.  First, let’s be clear, these are not my findings, they were the findings of Chrysler Corp and I am in no way taking credit for the results.  I was part of the ‘test crew’.

There were no wind tunnels involved and I’m not sure how mpg could be tested in one.  The test track was basically a highway built in a huge parcel of land along with other types of testing areas such as ‘water baths’, rumble strips, mud, gravel, and the like for testing different conditions of several vehicles.  Brake tests, acceleration tests, shocks, etc.  I think you get it.  (Some tests were conducted over major interstate highway systems).

The weight that was used for most of the tests was nothing more than sandbags placed directly over the rear axle.  Fun Fact:  The slots that are just in front of and just behind the Wheel Well are for 2×4 or 2×6’s to contain sandbags as a result of these tests.  The test vehicles (aka D100 or D200) were driven at 55mph, the max. highway speed at that time over a measured distance first from north to south, then south to north, then east to west, and finally west to east.  The tests I might add were done over many weeks, perhaps even months regardless of the weather.  In Michigan that could be anything from one minute to the next.

Now hopefully on to your final question, fuel economy.  Depending on direction and weather we were able to reach an estimated 5mpg, but we also saw only 2mpg.  The official finding that was included in our ‘Report’ was that a driver could expect an average of 2.5 to 3 mpg over tailgate-up driving.

I hope this answers all of your questions.  I also hope that TFLTruck will try this “myth” test again under the parameters set forth by the original testing guidelines.  Side note:  When I reached out to the Mythbusters they never responded, so Thank you!

Here is the original video that Ken is referring to.