Just returned from a restful week at the Lower Springs. There was only 6-8 people all week. Halloween was the lightest I have seen it in over 15 years !!
From Hwy 190 pavement trip took 5 hours in and 4.75 hours out. The leg from top of Grapevine to the bottom - 1 hour down and 45 minutes up ( because I knew where all the really bad sections were) . Average speed 2mph !!.
Most of Grapevine "trail" looks like this.....
This is the deepest hole (steepest when approached from the top down).
And another view
Rest of drive is slow because of the many (I counted over 40) washouts. There is a "covered with silt washout" about 2 miles east of the "Salt Tram"...Didn't see it until I bounced through it. (Great opportunity for a rest break as you re-arrange your gear) !!
Most of the visitors drove motorcycles and Jeeps. One Ford Escape Hybrid with stock tires, a Honda Pilot (blew a tire on road to Grapevine), one SUV pulling a Coleman tent trailer. No damage to trailer as it took him 9 hours from pavement (7 hours from top of the pass), Two Sportsmobiles, late model Tundra truck and shell, Two Four Wheel Camper "pop-ups" mine and a Hawk on a big 4-door Dodge truck.
My vehicle is a stock 2013 Tacoma 4WD carrying a 1300 pound Four Wheel camper Eagle shell. 10" ground clearance-Rear, 9 " Front. I did NOT "scrape" over any rocks. For this trip I had a 3 foot overhang. (one foot for the "step" into camper and two feet for bike rack). Overall length 20 feet. The only place I dragged was the second deep washout on 'Bat' "road". I creeped through all the worst sections in Low Range 2nd gear.
Worst hole on 'Bat' Road and the one I dragged on
One more view...
Just entering Bat road from Saline Valley Trail "intersection".
Summary: South is doable if you go slow. Go fast you will break something. Grapevine is too rough for Motorhomes, travel trailers, or big hard sided campers. In any case the bushes will "pin-stripe" your vehicle. Bottom 25% of Grapevine canyon is the worst section. "Bat" road is a close second with all its many washouts.
Remember if 3 guys and a mountain of gear can make it in in a stock Ford Escape with stock tires so can you just go slow and enjoy the trip.