Dumb 4x4 question
 

Considering I don't "need" 4x4 in summer months, would it be possible to drop
the rear drive shaft and use just FWD. Would reducing the frictional drag make a difference in MPG. Just a thought, any comments/polite suggestions?

Re: Dumb 4x4 question
 

Defeating the 4WD has come up in another thread. You can pull the fuse marked for the "4WD module only". Your dash "wrench" icon will come ON though and therefore mask if its turned ON by another problem. One 4WD FEH owner had done this and picked up the lost MPG.

Do this at your own risk as nobody knows if it causes any other issues but none have been reported yet!

Re: Dumb 4x4 question
 

With F/awd you have the additional weight and frictional losses of the PTO, driveshaft, rear diff'l, and both rear halfshafts. I doubt if you would see much in FE gain by removing just the driveshaft, or even removing the fuse, for that matter.The rear drive is RARELY engaged, overall, even pre-emptively, and in the summer months maybe NEVER reactively.

Re: Dumb 4x4 question
 

Read this post from the FEH owner that pulled the fuse: https://www.greenhybrid.com/discuss/204902-post65.html

They did notice the "wrench" icon later as it was covered up by their SG-II.

Re: Dumb 4x4 question
 

WTPSKI is correct. I am he 4WD MMH owner who pulled the 4WD fuse. I keep track of every tank of gas and associated MPG, and there is no doubt in my mind that I picked up approx 2 MPG, and noticed no other adverse effects. I did test the traction, by doing a "Rabbit Start" in a sandy covered pavement situation, and indeed only the front wheels spun. Also, in december, I returned the fuse to take advantage of 4WD for the northeast winters. My mileage has dropped due to the 4WD and the frigid weather. I plan to go FWD only again in the spring. I am thrilled with this flex-ability. I am sure that when I am in FWD only I do not get as good mileage as a real FWD MMH due to still carrying the weight of the rear drive gear. Hope this helped.


(NOTE: I stoppped entering my tank mileage into the Mileage section of GreenHybrid - but I still have the data and may catch that up soon. I now have approx 26,700 miles on my MMH)

Re: Dumb 4x4 question
 

You have a FEH but I could feel the difference in throttle response. With the fuse pulled it's my first expierence driving a V6 FWD FE!

Re: Dumb 4x4 question
 

I might be wrong, but I'd guess there is a center differential that splits torque between the front and rear wheels. If you were to unhook the rear drive shaft it seems like several terrible things could happen.

If you've ever seen how a 2WD car behaves when one wheel is on ice and the other is not, you know that normally the one on ice spins free and the other one with grip doesn't do much good at all (unless you have traction control or a limited slip diff). I think you'd run into a problem akin to putting your rear wheels on ice all the time. Not a good idea, IMO.

-dan

Re: Dumb 4x4 question
 

As stated, just a thought, but seeing as it could be as simple as disabling the electronics I might give it a try. Right now I seem to have settled into ~29.2 mpg on my circut to job.

Re: Dumb 4x4 question
 

"...only the front wheels spun.."

TC did not interceed...??

Is it possible that due to the fuse being pulled TC was disabled..??

Re: Dumb 4x4 question
 

The '08 and older FEH did not come with TC.

GaryG