Fast Lane Truck 2500 Fuel Mileage.....

You watch, I have mine, but what is wrong with this test?

https://www.youtube.com/watch?v=EswCPyQ0USk&hd=1

 

I saw 2 things. First is he had weight in the bed. Second is he barely went anywhere. He needs to run a full tank and then get his mileage!! Just running barely 2 gallons does not give you a good mileage report. JMHO.

 

Don't care how you toss it, it's still better than i get, Monte

 

you are not actually calculating how much fuel was used....by using the 2nd click, on the pump! Not even close.....Fill to you see in the neck.....

 

I tried doing the second click with my truck when I first filled up with this new fuel system and it just overflows. Now I just do it on first click and call it good. Sure wish I could get rid of the baffle/valve in the fill neck.

 

Same "Don't care how you toss it, it's still better than i get, Monte"

mercedes-benz servicing

 

I saw that same "test" over on CF several weeks ago.

It is laughable........ :-laf

 

I love these test. They don't give any specs. about the truck. Different tire size, or pressure, Differential ratio's.? with the blocks he tried to simulate the weight difference of a 4 wheel drive, I guess. Flat road way, medium traffic.

 

You can't compare fuel mileage of a 2wd truck to a 4wd truck. Sure they offset the weight but that's only part of the story. What they didn't account for was the parasitic loss that turning the transfer case, front driveshaft and front axle create. Even when the truck runs in 2wd, the front axle is still turning all the time.

 

Not any more. They've gone back to a disconnect system similar to the second generation trucks.

 

So where is this disconnect your talking about?

I know for a fact the axles turn 100% of the time and are locked in to the hubs. So the front axle is still turning the axles the whole time, again parasitic loss.

 

I can turn my front diff. by hand when I get under it, so it might be rotating through the spider gears, and the cade system. i have noticed the earlier 2nd gens as mine, that the diff sometimes rotate much slower that the rpm of the wheel when rolling. So there must be some disconnect some place. So ya, the left side, (short axle) is connected and is driven all the time as is the right shaft. So the system as a whole is partially in rotation. But at 22 mpg & @ 70 is still good for this vintage of truck.

 

I can tell you I jacked up the drivers front tire off the ground. I stuck a pry bar in the universal joint and you cannot turn the tire.

 

Todd,

If you are talking about the 2015 maybe the key has to be on for the axle disconnect to activate??? I have read that they are electric now and perhaps the power off default is locked in??? Just thinking out loud that maybe they decided failure mode would be locked???

Mike.

 

Yes 2015 and no I did not try with the key on, but will do so in the future.

 

The key won't make a difference for what you're trying to do. The disconnect is in the long axle tube (passenger side). The u-joint is always turning on both sides, but the ring and pinion won't be, as the only thing turning will be the spider gears in the front differential. Not turning the ring and pinion, driveshaft, and the output side of the transfer case is where the savings comes from.