From what I have read so far, sh-awd is special because it doesn't just send power to the back wheels when there is a loss of traction but it also manages left-right power distribution. Is there more or is that basically it?

I'm asking because I've always been a fan of awd vehicles and if sh-awd is as good as people make it out to be, the tlx would be more than interesting for me when the loans are going to come back to the dealers.

 

^^ You have the good idea of it....The Torque vectoring sends power not just front-to-back but also wheel-to-wheel to improve not only traction but cornering ability which makes the car feels like its on rail.

Now I could be wrong but I read that the TLX's SH-AWD also works when the car is decelerating and not just limited to when throttle is applied like it was on the 2009-2014 TL's. I could be wrong on that one but I am sure some people will correct me if I am

No doubt that Acura's SH-AWD is one (if not THE best) of the best AWD system there is on the market....

 

Eddie, you got to test drive both the FWD and SH-AWD versions to appreciate the difference. The FWD V6 was, sort of, OK, to me.... but once I drove the SH-AWD, the difference was obvious - I loved it! Oddly, it felt much lighter on its feet and more balanced overall. So the benefits are way more than just the usual AWD advantages.

Now, that was WITHOUT snow. With our lovely Canadian snow, you gotta love SH-AWD!!!

 

There is a gauge in the MID that shows power distribution to all four wheels. From what I have observed, it only does lateral torque vectoring (more diagonal actually) when accelerating through a turn, when it throws a lot of torque to the outer rear wheel, and supposedly the Agile Handling Assist applies braking to the inner wheels on a turn.

When accelerating in a straight line, it throws power to the rear wheels proportionate to the amount of throttle, but never above 50%. When decelerating, it seems to apply little to no power to the rear wheels, although the gauge is kind of "coarse grained" and not precise enough to be sure.

It is really impressive though. :-)

 

Nice thanks for the info! I was aware that previous versions disabled the system while decelerating in order to allow proper ABS application or something. All pretty interesting stuff.

The idea I had in my head of the sh-awd system didn't really differentiate it from Subaru's awd system. With those explanation I see what it's about

 

SH-AWD also over-drives the outside rear wheel based on steering input, slip angle, etc. It's what makes the car rotate so readily in the twisties. A lot like magic. As someone said above, you have to drive it to really appreciate what SH-AWD does. It's really an engineering marvel.

 

The 4g SH-AWD I had ruined me. I have to have it in the TLX too. Not that I need it here where I live but I like it and am having to wait to get it. It's just so fun to drive!

 

i remember asking this earlier and was told that's only on the RLX eSHawd

 

This function is only on the RLX Sport Hybrid. In that car, the vectoring happens on or off throttle, and it can even do regen on the inside rear wheel while turning. Coooooooool.

As I have said for almost ten years now: SH-AWD is the shiz. Just wait until the hybrid's eSH-AWD makes it to the TLX eventually. It is an incredible and unique driving experience. It can make anybody drive like a champ when they are just a chump.

 

^^ Much appreciated. I couldn't recall if it was the RLX SH-SH-AWD that had that feature or the new improved SH-AWD from the TLX.

Thanks for clarifying and my apologies to all for stating inaccurate information.

 

I wonder how a v-6 TLX with lighter P-AWS -vs- the heavier sh-awd on a road course. I'm assuming P-AWS works off throttle compared to sh-awd only working on throttle.

That is the only complaint I have on my RDX and MDX is the system works only under power. Not as fun going down the mountain compared to driving up in a top heavy SUV. One thing about the MDX is more than 50% TQ can be sent to both rears when needed or one wheel on a turn with the sh-awd system. I've seen up to 70% to both rear tires and around 80% to just one rear tire on a tight turn. I'm lucky to get 50% to both or 30%-40% to one tire on a really tight turn on my RDX.

The only other down side is little more tire wear because of the awd of the sh-awd.

 

P-AWS is controlled by the rotation of the steering wheel, so it works both on and off throttle.

 

The new gen SHAWD also has brake torque vectoring.

 

AH HA!! I thought I read that somewhere too....Now we could both be wrong but at least Ia m not the only one. Now I got to go and investigate further *lol*

 

So the SH-AWD in the TLX trumps the LSD in the Civic SI or are there any advantages to the LSD aside from cost and mechanical simplicity?

The 2016 ILX looks interesting but it seems without SH-AWD or at least LSD, it's not going to be planted firmly on the ground on wintry road conditions and on bends and possibly not much better than our 11 Accord in terms of handling.

 

The problem I see with sh-awd in the ILX and I-4 TLX is the system takes away engine HP to work. I think the drive-line loss is about the same as most AWD system and up to 35%- 40% when the HP hits the ground. The Cheaper CR-V/RDX system is an on-demand system and might have less drive-train loss overall since you will use it mostly at lower speeds (low speed traction compared to high speed handling). My 205hp 06 TSX 5AT at 3200-3300lbs barely has enough HP on a curve to power out. Add in sh-awd+extra weight, I might actually lose speed in a corner. I can see the 2.4L ILX/TLX going with the RDX 4WD system; unless, Acura goes with electric sh-awd like the NSX/RLX.

 

I was wondering, those of you that have the SH-AWD do you leave the auto idle stop function on or turn it off (which I believe you can do) because you don't like it.

 

I always turn off the Idle-stop feature. I do not like it and it feels unatural and a bit disconcerting to have the engine cut off everytime the car stops. I would've appreciated the ability to disable it permanantly as opposed to the car defaulting this feature to 'on'.

 

Even though it defaults to 'on' once you turn it off I'm assuming it stays off for that current drive, until you park the car turn the car off. Then start the car again and disable the feature again, right?
This is s noob question and I think I know the answer but here it goes. Does turning off the idle stop feature effect the SH-AWD system off th car? I don't think you can turn off the awd aspect of the TLX.

 

(A)gile (H)andling (A)ssist will use the brakes on the inside wheels to help turn the car, but only in relatively low speed, relatively tight turns when it is clear to the car that you need that kind of assistance.

It coordinates with SH-AWD but it is not an integral part of the same system, and AHA only activates under a very clear set of circumstances.

Something that this generation of SH-AWD does that the previous generation did not do is that the system operates at freeway speeds with relatively gentle directional changes, like when you're changing lanes at 70 mph.

It's a subtle change in the feel of the car, and supposedly contributes to the overall performance. Seems a bit odd to me, but what do I know. :-)

 

AHA also exists in the entire range of FWD Acura cars, too.

 

I knew we'd hear this kind of criticism. Some of the reviewers complain that it takes too long to start the car and that it jerks too much.

This is sheer conjecture on my part, but I think we're hearing these complaints because it is new technology for Acura. Other brands of luxury and near luxury cars don't do it any better than Acura, IMHO. Their drivers have just got used to it by now.

Having driven both systems, I can say that it works significantly better in the Sport Hybrid.

You barely notice it at all.

In the first place, because you have two rear electric motors that start you moving before you need the gasoline motor.

But in the second place, because the J Motor is started by a 47 HP 250-volt motor, not the backup 12-volt starter motor. When the Sport Hybrid's J Motor starts...it's just suddenly *ON* and you're off.

I wish that people could think of a better way to do it with the TLX, but I can't imagine what that would be.

And if nothing else, the start-stop system allows you to get the same average gas mileage in the SH-AWD car that you'd get in the P-AWS car (25 mpg).

 

Quite true. I often can't tell when the engine goes on and off, when I'm on the freeway in traffic.

 

When I said "Ah ha"...It was meant as me expressing myself...as in "See, I wasn't the only one thinking that the new SH-AWD also was active during the non throttle. Sorry for the confusion...