Tongue Weight and Mileage

[Alan Reagan]

Last week I had to tow the tractor and a larger than normal (for me) bushhog to NE Georgia. Total weight was 9K. The length of the bush hog forced me to move the tractor forward approximately 18 inches from where I normally haul it. Usually I center the rear tractor wheels between the trailer tandems but this trip I was almost over the front tandem (18 ' trailer) with the rear tractor wheels. This caused more tongue weight. As a result I saw my mileage fall to 13. 9 for the round trip. Usually it's around 15. 5-16. I'm wondering if you guys have seen a correlation of tongue weight to mileage. Except for one good drag race for a mile uphill, I drove the way I normally drive which is about 60 to 65. Moving the tractor forward really made me feel the load. Also, the trailer was still level. Once I dropped off the bushhog after I got home and was pulling just the tractor in its normal position, It felt like I didn't even have a load. That would have been about 7 K.

 

[mbrolin]

99 Ram 4x4 SWB pulling TT with a GCVW of 14k had mileage of 11. 5s. This was my old truck. Present truck is a 01 HO 4x4 LWB pulling a 5er with a GCVW of 18,500k. Getting 11. 5 mpgs. Go figure

 

[Steve Campbell]

Alan, I am going to guess that the fuel mileage is more of an aerodynamic issue (larger than normal bush hog) than tounge weight. Size of objects and their relation to how the air is leaving the towing vehicle makes a BIG difference in mileage. Some think I am full of it on this issue.

 

[Alan Reagan]

Here's what I was thinking. Yeah the bush hog was larger but not really heavier than the other one I use. Just longer, forcing me to carry more tongue weight when I moved the tractor forward. More tongue weight causes more weight on the rear wheels, more bearing resistance, more tire resistance... ... ... . See what I mean. If the load is shifted more to the trailer, I think I might have gotten my normal mileage. Instead, my mileage suffered.

 

[John Berger]

Alan, the only possible flaw in your theory would be whether there was a significant drop by the truck when you moved the bush hog forward. Did you notice any difference? Once the rolling resistance of the tires (and bearings?) are overcome then drag(aerodynamics) becomes the primary force the engine must overcome to continue moving at a set speed going down the road. Another thing to consider is fuel. Did you just get a lower grade of fuel this particular time? Was it hotter than normal? Crosswinds maybe? If you experienced a significant drop, the problem may be that the front end of your truck became less aero tolerant because of more lift at the front end than normal. I don't know for sure as this is all speculation, but it's a great way to get a post and kill a bit of lunch hour

 

[Alan Reagan]

You, sir, caught me. I wanted to check mileage so I stopped at a Citgo after I got loaded. From this station I have gotten 1. 5 to 2 mpg less in the past. Didn't even think about it as much as I tell everyone about the quality of fuel. I only took on about 12 gallons but now that you mention it and my past experience with Citgo, things make a little more sense. After unloading, I refueled to check mileage at my normal watering hole and went to Atlanta. Refueled today and mileage was 21. 6. It should climb back to 22+ now that all that Citgo is getting out. I thought the engine was a little noisier. Glad I didn't take on 37 gallons.



However, in my theory, it seems like the truck has to pull harder with more tongue weight. Maybe it's because of the stiffer ride with the rear leafs more compressed.

 

[brobeson]

tongue weight

The tongue weight does not effect milage, only the overall wieght, and its areo dynamics.



By moving your load forward you may have loaded the truck more, but it unloads the trailer by the same amount.



It would be my guess that the truck would see less effect on MPG than over loading the trailer, so I would think your milage would be higher as you load the truck more.





Bob