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GT Auto vs. Manual AWD trade-offs


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I am considering a purchase of a Legacy GT wagon. Our test drive of the Manual was impressive and we were very happy with the car and perfomance. Everything I read seems to point to the Manual as being the way to go. However, I'm trying to understand the trade-offs when it comes to AWD.

 

The Manual comes with continuous AWD while the automatic has the VTD set up. I've seen other postings here about the differences between the various systems. What I'm tryinig to understand is what the real world differences would be. While everyone seems to agree that the Manual is better in terms of driving performance, does the Automatic's more sophisticated AWD provide better performance or safety in wet or snowy conditions.

 

I'm trying to understand if the different AWD systems are used simply because they match up better with the different transmissions or is there a real beneft to the VTD vs. continuous AWD that should factor into the decision of Manual vs. Automatic?

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you can check subaru's website for a description, or do a search of the threads on this site. Basically the manual has the power split 50/50 between the front and back at all times. The auto is 45 front and 55 rear or the other way around. Both are great systems, but the manual has the egde in delivering more power to the wheels...more is lost throught the automatic trans. 60 times prove this....manual 5.6-5.8 and auto around 6.5.
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The auto GT 5eat is the most advanced system. If it were mated with a manual transmission it would be akin to a non adjustale STi DCCD system.

 

The auto's AWD is the more advanced of the two.

 

The manual is better around the track because of the simple fact that it is a manual and it offsets the deficencies compared to the 5eat system

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Thank you for your comments but I guess my question may have less to do with the track or 0-60 performance. When the weather turns and it comes to starting, stopping and highway driving in slick conditions, is the AWD on the automatic preferrable to the stick?
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I have to say that Subaru has done a good job with the 5MT. By far, one of the easiest sticks I have ever driven. Clutch is low and short, just like I like it. The shifter could be a little less clunky and more "Hondalike", but it works just fine (especially with the STS).
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Thank you for your comments but I guess my question may have less to do with the track or 0-60 performance. When the weather turns and it comes to starting, stopping and highway driving in slick conditions, is the AWD on the automatic preferrable to the stick?

 

somebody will correct me if i'm wrong - but i'm under the impression that the AUTO was given the VDT to offset the power loss of the automatic transmission. (able to have a rear wheel bias to get more power to the pavement)

 

when it comes to road handling and traction - i would expect that both systems perform very similar, if not almost exactly the same. Your best bet is to get the car you're comfortable driving, and then swap out the stock tires for a better set. --- that will yeild the best traction gains.

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Yes, because VTD uses planetary gears, it probably does lend to less drivetrain loss compared to a viscous coupling unit (it's interesting to think that all Legacys have some "slush" in their drivetrain). However, I believe the main reason why Subaru continues to put VTD in more of it's vehicles is simply because it is a more advanced and arguably better system. With AWD becoming more prevalent and more vehicles with "smart" systems, Subaru probably feels that the good old fashioned VC will soon become a competitive disadvantage.

 

The VC is a reactive system that basically needs wheel spin to start reacting. VTD, on the other hand also uses an electronically controlled clutch pack to vary torque for and aft (hence the name VTD).

 

This electronic control allows Subaru to integrate more of the vehicles controls together. One example is ABS. With the TCU/ABS sensor and ECU working together, a VTD equipped car knows not to apply torque towards the wheels that are pending lock up. Another would be hard acceleration or braking. The TCU can control VTD to shift torque towards the wheels that would have more weight transfer. Lastly, throw in some yaw sensors and a stability program -- voila: VDC. This level of integration isn't possible with the VC.

 

How do they compare up in real life use? For the most part, both systems work very well in poor weather. I've driven both types of Subarus in snow and ice. However, at the extremes, the advantage of VTD does show. A VC equipped car will oscillate power front and back when you're on the really slick stuff. Imagine the fronts break loose, the VC begins to lock and send more torque to the rears, now the rears break loose and it sort of goes back and forth. With VTD the action is more stable and there less "looseness" in the drivetrain. The difference really does show when climbing a steep muddy or icy hill.

 

Also, the slight rear wheel bias of VTD, from those who have been on the track, does seem to aid in rotating the vehicle. But again, this is at the limit.

 

Should VTD vs. VC be factored in the purchase of manual or auto? I don't think so. Choose your tranny based on what each one can do for you. If you get the auto, look at VTD as being icing on the cake.

 

Ken

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Buy the automatic due to such a short first gear and the stinky clutch problem. There's a huge thread in the warranty forum.

 

Subaru's clutch delay valve makes it seem like know one knows how to drive manual.

 

I'm thisclose to trading my 5 speed for an auto because it's that bad.

 

Jason

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^^ Thats just plain stupidness, the manual tranny is fine, even with the CDV. My M3 has a CDV as well, and you get used to it. Any new clutch needs to be broken in. We barely noticed the smell on ours, just when it was slipped alot. Now that we have 2000 km on the car, the smell has gone away completely.
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^^ Thats just plain stupidness, the manual tranny is fine, even with the CDV. My M3 has a CDV as well, and you get used to it. Any new clutch needs to be broken in. We barely noticed the smell on ours, just when it was slipped alot. Now that we have 2000 km on the car, the smell has gone away completely.

 

Please disagree respectfully. No need to call anyone stupid because you don't agree with their opinion.

 

Having said that, I agree that the manual is fine, even though the smell is annoying anytime you slip the clutch.

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Buy the automatic due to such a short first gear and the stinky clutch problem. There's a huge thread in the warranty forum.

 

Subaru's clutch delay valve makes it seem like know one knows how to drive manual.

 

I'm thisclose to trading my 5 speed for an auto because it's that bad.

 

Jason

 

 

Short first gear?

 

1st gear gets you up to 40 mph... Thats pretty long... Its short because the car has power :D

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does the Automatic's more sophisticated AWD provide better performance or safety in wet or snowy conditions.

 

I don't know if the auto is better, but the manual is good enough to drive 60mph or so on snow covered, slippery roads. It has a very good connected feel between the go pedal and the tires. I can modulate the throttle to keep the traction & wheel spin within the limits of the tires & roads.

 

I've always thought that having an auto under slippery conditions was worse than a manual, because the engine & wheels are connected via fluid, not steel. The torque converter is never predictable enough to permit precise control of traction & wheel spin.

 

--Mike

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Precise control of traction & wheel spin is exactly what the VTD is there for.

 

The viscosity of the fluid is such that when it locks, its no different from steel. Its liquidity contributes to balance the transmitted torque to enhance traction.

 

Best to test drive the AT model as well to get first hand experience.

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WRT the differences between the 5MT and the 5EAT in the LGT, for normal bad weather driving I don't think you'd see much difference. However, when things get really sloppy and nasty (major snow and ice), I typically manually shift the auto and keep it in 1 or 2 so that the two axles are "locked" similar to the VC in the 5MT.

 

You'd be hard pressed to detect much difference between the two in normal driving. They are both seamless AWD until you get to the upper limits in the 5EAT when the rear can tend to rotate more readily due to its rear bias.

 

SBT

- Pro amore Dei et patriam et populum -
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sjg

 

Did you intend to pose this question twice? Thread merged with the other thread of the same title that you originally posted.

 

SBT

- Pro amore Dei et patriam et populum -
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Yes. I did post twice. Not sure what happened. I only intended to create one thread.

 

Thank you for all your responses. Some of them are very helpful. There seems to be a good deal of confusion on how these things work but it's good to be reassured that the AWD with the manual doesn't really give up much to the VTD in terms of safety and performance.

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