I kind of forgot about this thread. Sorry guys. :lame:
There are several good points mentioned for and against it. If I were to change gearing I don't think I would want to go any further than a 3.73. I have this truck to pull my race car trailer, hence my user name, and that's pretty much it's only function...well other than the occasional :tree:
However, it is sad to see that you drive like a granny all the time
NO! I just don't like getting tickets. I live in Kansas man, it's 50 miles to the closest interstate so I'm driving 65 mph speed limit roads 90% of the time.
David Whitmer wrote:
“90% of the driving I do I don't run over 70 MPH, so maybe it aint even worth it.”
‘Tain’t so! By slowing down the engine at any road speed, you cut the engine frictional HP and thus reduce fuel burn
Dave you must keep in mind I am pulling an enclosed car trailer (flat front) that weighs aprox. 12K lbs. when I am wanting to gain fuel economy.
I recently took a 450 mile round trip towing the trailer the entire time. I was running 75 to 80 mph 70% of the trip and 65 to 70 mph 30% of the trip. My average economy was 10 mpg. I have been averaging 10.7 mpg on 60 to 70 mph driving pulling the same trailer.
David Whitmer wrote:
I went from 3.73s to 3.08s and picked up 3 MPG in my mixed city/suburban (35%), Interstate (30%) state roads (35%) driving loop. Actually its my 42 mile one-way commute. Why did i go to 3.08s? because i couldn't find any 2.73s.
If I changed from 4.10 to 3.73 that would be a 9.02% change in gear ratio. You changed from 3.73 to 3.08 that would be a 17.43% change in gear ratio. If the percent of gear ratio change would affect fuel milage proportionally on my truck towing a trailer as it did your truck driving empty (probably wont happen, but for the sake of disscuson we will assume) then I would expect to see a 7.06% gain in fuel economy (this assuming that your economy gain of 3 MPG was going from 19 MPG to 22 MPG and getting a final gain of 13.64%). A 7.06% gain in fuel economy would equate to a .75 MPG gain on my truck
= .1364 = 13.64%
9.02% gear ratio change
17.43% gear ratio change 13.64% MPG gain
X = 7.06% MPG gain on my truck
7.06% (or .0706) * 10.7 MPG = .755 MPG gain
I think I am talking (well typing) myself out of the gear change idea...