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AWD vs. 4WD: Why the switch?


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I have a 93 Loyale and proudly pulled a big Jeep Grand Cherokee up an icy hill the other day.:banana: I'm hooked!

 

Question: The older Subarus were selectable 4WD, with full time front and part time rear, if you pushed the button. Works great. Easy to use. No problem. The newer Subarus seem to be AWD, which sounds easier (I suppose.....) but everyone I know with one says they aren't getting nearly the 30-31 mpg I get with my old one. Is it the AWD vs. 4WD or is it the new smog stuff, or both?

 

cnc

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83 GL: 2,100 lb

11 Outback 2.5i: 3564 lb

 

1464lbs is a lot of weight to move around.

 

Drivetrain loss between awd and 4wd is part of it, but not most. You still have parasitic loss with Subaru 4wd because the rear diff is always spinning, even if 4wd isn't engaged. There's no disconnect in the hubs like on trucks.

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Im thinking it has to do with people not knowing when is ok to use 4wd and when its not ok. Im sure there were plenty of people out there running around in 4wd on dry pavement ruining their transmission and putting strain on the entire drivetrain. My guess is subaru decided to make it easier on the less informed people (read morons lol) and just make a system that was in awd and could be used with no ill effects in the dry/wet/snowy. Takes the thinking out of driving a car which is what america seems to like :rolleyes: Im not basing subaru at all btw. AWD is great and ill probably own one eventually.

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Im thinking it has to do with people not knowing when is ok to use 4wd and when its not ok. Im sure there were plenty of people out there running around in 4wd on dry pavement ruining their transmission and putting strain on the entire drivetrain. My guess is subaru decided to make it easier on the less informed people (read morons lol) and just make a system that was in awd and could be used with no ill effects in the dry/wet/snowy. Takes the thinking out of driving a car which is what america seems to like :rolleyes: Im not basing subaru at all btw. AWD is great and ill probably own one eventually.

 

I think this is definitely true.

 

Me either, uberoo. That's why I'm looking for an 80's model. I was told that you could get the stick shift 4WD/FWD in Europe but not here. Don't know if it's a Hi/Lo or not.

 

You could get dual-ranges at least up until the last few years. But once they started the EJ platform, they're all AWD. There was one guy in New Zealand claiming he had some EJ D/R FT4WD transmissions with a center diff lock, but he couldn't/wouldn't back up that information. Either way, there was no selectable FWD option.

 

 

 

From a performance standpoint, AWD is much better in pretty much every way. The Viscous coupler in the center diff is very strong, so at slow speed offroad, it does not slip very much. But it does allow enough slip to be used on the pavement. And a little bit of slip helps the front tires bite on corner entry which combats understeer.

 

Center diffs are fairly strange. In a performance situation, stronger is better, but actually mechanically locked is much worse.

 

 

 

Really the only aspect of the car that would benefit from selectable FWD/4WD is fuel economy, and it's pretty obviously from the size and weight of subarus over the last 20 years, that fuel economy is not high on the list.

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You could get dual-ranges at least up until the last few years. But once they started the EJ platform, they're all AWD. There was one guy in New Zealand claiming he had some EJ D/R FT4WD transmissions with a center diff lock, but he couldn't/wouldn't back up that information. Either way, there was no selectable FWD option.

 

I've seen at least a dozen different pictures of dual range EJ cars, from the factory.

 

Australia, South America, etc.

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I've seen at least a dozen different pictures of dual range EJ cars, from the factory.

 

Australia, South America, etc.

 

I owned an EJ D/R transmission here in the US for a couple years. But it used a standard EJ VLSD center diff (AWD). Not locking Full-Time 4WD, or selectable Part-Time 4WD.

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I owned an EJ D/R transmission here in the US for a couple years. But it used a standard EJ VLSD center diff (AWD). Not locking Full-Time 4WD, or selectable Part-Time 4WD.

 

Ah I misunderstood what you were saying. My mistake.

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I believe another reason for the disappearance of FWD is the power of the EJ.

If you'll notice, most of the high power EA based models, such as the RX and XT6, came with optional or standard full time 4WD, the predecessor to AWD.

 

Plus, nobody likes torque steer and with the torque of the EJ22 even, it likes to pull whichever direction has the least traction.

AWD smoothed that out and provided full time traction for said people who didn't know when 4WD was supposed to be used.

And with the AWD drivetrain smoothing out power delivery, it eliminated the need for a front LSD :-\

 

Twitch

Edited by Twitch de la Brat
Full time 4WD, not AWD.
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I cant speak for diff lock, but Foreign Engine in Lynnwood will occasionally get an ej d/r awd 5 speed out of Japan although they got mostly auto's. I called a few months ago and they had one for 800.00. The fellas in Au have these trans and chase the rx low range gear set for them, apparently its not much of a low range from the factory.

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I can personally vouch for the need for awd with the ej engines.

 

I had a ej22 swapped EA82 wagon with the DR 5 speed.in FWD it would incinerate both front tires in 3rd gear at 25 mph if I punched the gas.It was hell in the lower gears to get it moving without burning the tires to the cords.But DAMN it was fun when it hooked up...

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Another reason why I snagged up a clean EA81 at first glance.

 

My '84 GL has just 130k miles on it, and is 100% rust free.

 

Looking at just how little I drive, Ill have this car until I die.

 

Between 3 vehicles, the wife and I routinely drive less than 5k miles per year. The GL will be getting less than half of those. But even assuming that I drive it 3k per year, it will take me a LONG time to wear out this little car :)

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I can personally vouch for the need for awd with the ej engines.

 

I had a ej22 swapped EA82 wagon with the DR 5 speed.in FWD it would incinerate both front tires in 3rd gear at 25 mph if I punched the gas.It was hell in the lower gears to get it moving without burning the tires to the cords.But DAMN it was fun when it hooked up...

 

That has a lot to do with the EA82 suspension, alignment (mostly the camber) and skinny tires. as a FWD EJ has a TON more traction. This spring, my old FrankenWagon will be getting re-5-lug swapped, but is still PT4WD. So we'll see if dialing back the camber helps.

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I like the AWD in my daily commuter suby. Going from snowy to dry pavement in the winter, my nasty driveway to pavement, doing hill stop on a steep slippy hill that turns into pavement 10' later... AWD is wonderful

 

Now I LOVE the 4wd in my GL, especially with low range. In heavy snow, offroad, getting unstuck, pulling people out, etc. The locked center is absolutely awesome.

 

So the way I see it is, 4wd is more fun offroad and playing around, but AWD is a lot better for just everyday driving. AWD is also wonderful for street performance. 4wd can't even compare in that respect.

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Street performance is definitely better with AWD.

With a locked center the front likes to push out.

With the viscous center diff the front can grab and pull while the rear pushes.

 

Rally and low traction situations also benefit from the limited slip center as understeer is ever more present with low traction.

 

And only if you have enough power to overrun the tires and just make them all burn is 4WD more effective than AWD in loose dirt/snow conditions.

But this most generally only applies to racing, not normal driving.

AWD almost always is better for normal DD duties.

 

Twitch

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gee I must be missing out then.My daily driver is RWD...

 

 

 

 

 

 

 

...and I wouldn't have it any other way.

 

my subaru is soon to be RWD,with the option of shifting into 4wd...

 

speaking of that hows your nissan coming along?

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