4 wheel parasitic loss

[murdockrecords]

What would you guys say the parasitic loss factor (transfer case etc.)for a 4 wheel drive truck versus a 2 wheel drive? In a percentage? For instance, same motor, same trans, weight everything - the only difference is 2 wheel versus 4 wheel. What's a good percentage number to use?

[surfnuke9]

as far as mileage?

I would say 10 percent.

[murdockrecords]

Sorry, horsepower/torque to the pavement. And there may not even be a statistical number that is accepted. I guess a better way to ask would be - how much "load" does the 4wheel drive assembly "take away" from the power/torque of an engine. (In theory). There's the add for the extra weight too.

[nfury8]

Could depend on the transfer case. I would imagine the gear driven 205 is the worst and a chain drive would be better.

[murdockrecords]

I would concur with Tim on 10% for fuel mileage. But I had a chevy guy tell me that power loss (drag) due to transfer case, weight, etc. is around 25%. Apples to oranges sure, but I could not believe it. Just wondering what you fellas thought.

[surfnuke9]

I would bet its close to the same for power loss. Its just gears or a chain after all....not much loss there as compared to an automatic trans.

[Kaegi]

O loss because of Tcase. on pavement you are in 2 wheel drive and no gears are turning in the Tcase/ so the only factor sucking power is the 1000 plus pounds of extra weight and the fact the the shoe box shape of a sweptline is harder to push when it is 6 or 8 inches higher off the ground than a D-series. I concur with the 10% guess. in later trucks with full time higher than 10% for sure.