Fixed Fifth Wheel.

When I got the job at my last company, there were problems with my sliding fifth. Seems the ram wouldn't lock the fifth wheel back in place after you slid it, so you had to beat it in place with a hammer. I just slid it all the way back and ran like that for a few years. Never encountered anything that I couldn't correct by sliding the tandems (although I did have one load that was within 30#). The fact that I could move the fifth wheel was completely irrelevant.

However, that was a company job where the company was paying for fuel. Fifth wheel in that position left a pretty big gap between the cab and the trailer, so it had to have been hurting my mileage. Would take someone more knowledgeable than me to say how much, but I'd have to think that being able to tighten things up would have to be a bonus to someone paying for their own fuel.

 

Like most folks have said--you will probably be fine--There's 1.6m on My pete--and I've move the fifth wheel once--when I parted w/my spread and started pulling a tandem 53'--slid it then--and that is where it sits almost 850k later--lol
The one thing I would do--is(and you can do this w/out a trailer if you prefer)is weigh the truck light on fuel and then weigh it fuel--just to get a feel for the weight dist ratio of your fuel--ie:How much weight goes on your steer vs how much on your drivers?
I have mine(Which has nothing to do w/anything but MY truck)at right about 60/40--meaning 40% of fuel weight goes on steers and 60% on drivers...
Or to get even more technical--approx-3.04lbs per gal on steers and 4.56 lbs per gal on drivers--LOL
Good luck