02 or 09 awd question

[wptski]

Originally Posted by Octane You wont see much of a difference going to a newer Escape. The newer ones are a little bit bigger and roomier, but arent any more capable on snow/ice. They drive mostly with the front tires and as they sense a loss of grip they send more power to the rears. My girlfriend has an '08 Escape 4WD V6 and we love it. Its good in the snow, has pretty good performance for a compact SUV and its so easy to change oil on. It seems to be pretty solidly built too. You could say that a new 4WD Escape operates like a FWD only after shifting into 5th gear, before that, your in 4WD. Rear wheel torque seems to drop off slowly after accelerating from a stop.

[Octane]

Originally Posted by wptski

You could say that a new 4WD Escape operates like a FWD only after shifting into 5th gear, before that, your in 4WD. Rear wheel torque seems to drop off slowly after accelerating from a stop.

Basically thats now a Torsen (torque sensing) system works. It sends the power to the wheels that have the most grip.
It drives mostly with the front tires (I think its something like an 80/20 split), but when you accelerate, it senses that the rears have more grip, so it sends more power to the rears.
All I need to do is look at the tirewear on my g/f's Escape to see that it drives mostly with the fronts though. The fronts definetly wear more than do the rears.

[wptski]

Originally Posted by Octane

Basically thats now a Torsen (torque sensing) system works. It sends the power to the wheels that have the most grip.
It drives mostly with the front tires (I think its something like an 80/20 split), but when you accelerate, it senses that the rears have more grip, so it sends more power to the rears.
All I need to do is look at the tirewear on my g/f's Escape to see that it drives mostly with the fronts though. The fronts definetly wear more than do the rears.

I can't speak for other years but a '09 you can't accelerate without rear wheel torque or said better you can't even touch the accelerator pedal without generating rear wheel torque. I'm talking about dry pavemnt. It just shouldn't be that easy to generate rear wheel torque. I don't see the need to waste gas.

Power sent to the wheels with more grip suggests wheel slippage, where's the slippage on dry pavement? This is the way I originally thought the ITCC 4WD system worked but I find out differently now.

I suggested in a hybrid forum that the 4WD could be disabled by pulling a fuse and a owner of a MMH has done that. On a frequent trip to his cottage, he has gain 2-4MPG. The downside of that is that the "wrench" dash icon lights up with the fuse pulled but goes OFF when the fuse is replaced.

I had my fuse pulled for a while and felt a bit more response. There must be some adaptive learning strategy loss with the fuse pulled because I see a bit of rear wheel torque now even at 40MPH when the accelerator is nailed a bit. I seen that early on in my testing which went on for weeks but it stopped.

[Octane]

Originally Posted by wptski

I can't speak for other years but a '09 you can't accelerate without rear wheel torque or said better you can't even touch the accelerator pedal without generating rear wheel torque. I'm talking about dry pavemnt. It just shouldn't be that easy to generate rear wheel torque. I don't see the need to waste gas.

Power sent to the wheels with more grip suggests wheel slippage, where's the slippage on dry pavement?

It senses which tires have the most grip and sends more power to those tires.
Since the rear is only getting 20%, they have more grip so when you accelerate, it sends more torque to the rears because they have that most grip.
Because the front gets 80% and the rears only get 20%; the rears have the most grip.
The difference in fuel milage from an AWD setup like the Escape has to the on-demand setup like what some Explorers have and what the Expedition has, where it doesnt send power to the fronts until the rears lose traction is marginal because even with the on-demand setup, you are still spinning the front differential and halfshafts all the time.
Personally, Id gladly give up a little gas milage for the sure-footed traction on snow/ice that AWD gives you.
My girlfriends V6 4WD Escape gets 25 mpg on the highway. I recently switched it over to Motorcraft 5w-20 semi-synthetic oil and air the tires up to 38 psi and it gained about 40 miles of range. When she used to fill the gastank it estimated a range of 290 miles and now when she fills it up, it estimates a range of 330 miles.
If gas milage is that much of a concern, dont buy a 4WD Escape.

[wptski]

Originally Posted by Octane

It senses which tires have the most grip and sends more power to those tires.
Since the rear is only getting 20%, they have more grip so when you accelerate, it sends more torque to the rears because they have that most grip.
Because the front gets 80% and the rears only get 20%; the rears have the most grip.
The difference in fuel milage from an AWD setup like the Escape has to the on-demand setup like what some Explorers have and what the Expedition has, where it doesnt send power to the fronts until the rears lose traction is marginal because even with the on-demand setup, you are still spinning the front differential and halfshafts all the time.
Personally, Id gladly give up a little gas milage for the sure-footed traction on snow/ice that AWD gives you.
My girlfriends V6 4WD Escape gets 25 mpg on the highway. I recently switched it over to Motorcraft 5w-20 semi-synthetic oil and air the tires up to 38 psi and it gained about 40 miles of range. When she used to fill the gastank it estimated a range of 290 miles and now when she fills it up, it estimates a range of 330 miles.
If gas milage is that much of a concern, dont buy a 4WD Escape.

Where do you get this 80/20 split from? Once you reach a steady speed there's no torque going to the rear.

How do they detect grip? Grip means less slippage and inorder to detect slippage, a wheel would have to rotate a bit. Rear wheel torque is immediate and before a wheel can even make a full rotation.

This system just doesn't work as many think it does. I wouldn't call 2-4MPG marginal. I'm not talking about winter driving but summer driving.

EPA states 1MPG less city and 2MPG less highway driving with 4WD.