Gotta love the STS4

[eightshb]

Originally Posted by dkozloski

The '05 has an open center differential, the '08 has an controlled slip center differential.

I am not an rocket scientist why did GM do that? and can my 05 be changed? It is really unsettling to lose the car before the AWD kicks in

[lreddiablo]

There is the software update for the tranny, but i think that has to do with shifting more, not sure if it improves awd features.

[shudog]

its great to read that the STS 4 does so well in the snow, but I've also been following some posts about the significant fuel mileage penalty for the all wheel drive... I live in Michigan also but I think there are maybe 10 days a year that I might NEED all wheel drive. I think I'd rather have the increased mileage those other 355 days a year.

[pjbizjak]

The 4 on an STS4 was added in 07, the 05's & 06's just said STSD even if you had AWD.

[AllWheelEric]

Originally Posted by pjbizjak

The 4 on an STS4 was added in 07, the 05's & 06's just said STSD even if you had AWD.

I'm not completely sure I get your point. Are you referring to the lettering applied on the trunk? My 2005 is marked STS4 on the trunk. I have heard reports that this varies from car to car, so I wouldn't make any absolute statements.

[AllWheelEric]

Originally Posted by shudog

its great to read that the STS 4 does so well in the snow, but I've also been following some posts about the significant fuel mileage penalty for the all wheel drive... I live in Michigan also but I think there are maybe 10 days a year that I might NEED all wheel drive. I think I'd rather have the increased mileage those other 355 days a year.

Don't underestimate the value of the AWD in rain. I didn't think of this before buying but now find that it's a real confidence booster. You're giving up 1-2 MPG with AWD, but either way this is one thirsty car. Perhaps if you want high(er) mileage in a performance car, you'll have to get a Corvette.

[Slo-Mo-Shun]

I'm curious as to exactly what you think the benefits of 4WD are in the rain?

As far as entering into and going through a turn are concerned, you could get the same benefit by strapping a couple of sandbags onto the hood. I respectfully suggest that 4WD gives zero benefit until you're coming out of the turn, at which point it is of great benefit to off-road rally drivers when they floor the go pedal, but probably not much to those driving legally on public roads.

[tomm]

Originally Posted by Slo-Mo-Shun

I'm curious as to exactly what you think the benefits of 4WD are in the rain?

As far as entering into and going through a turn are concerned, you could get the same benefit by strapping a couple of sandbags onto the hood. I respectfully suggest that 4WD gives zero benefit until you're coming out of the turn, at which point it is of great benefit to off-road rally drivers when they floor the go pedal, but probably not much to those driving legally on public roads.

With my RWD STS using a smaller engine V6 255 HP in the rain I alway got traction control coming on and in many occassions the rear would slide when accelerating in the rain. I have NEVER had this happen with my STS AWD with 320 HP.

[Slo-Mo-Shun]

I'm not questioning the ability of 4wd to give one better traction coming out of the hole, i.e, when accelerating.

Still, I've never had that kind of problem with a RWD street car, even in my old 1970 muscle car with an open diff, so long as I exercised any reasonable modicum of discretion (i.e., don't pitch the car sideways and floor it). And I live in Seattle, so I've seen a little bit of rain. .

When I bought my buick park avenue (FWD) I used to encounter excessive traction loss, but that could be traced to totally crappe oem tires. I switched tires and the problem went away. If you were frequently encountering traction loss with a 255 hp car in simple rain, the tires have to have been pretty bad.

It seems to me that a lot of oem tires have hard compounds to boost that EPA mileage figure on the window sticker. My mileage did drop about 0.5 mpg when I switched to better tires on the Buick, but now I really have to stand on it to break the tires loose and get stabilitrac to kick in.

[shudog]

I just got rid of an LS1 Camaro with about 320 rwhp which I daily drove for years through all types of weather, without any traction control or active handling/stability. I think I can manage to keep the rwd STS shiny side up and I'd rather have the increased mileage. Plus in Michigan, I can use it as a bargaining point if I find a car that isn't awd.

[AllWheelEric]

Originally Posted by Slo-Mo-Shun

I'm curious as to exactly what you think the benefits of 4WD are in the rain? ...

On a 2WD car, it's very easy to get the drive wheels to break loose in the rain. Even my 200HP Mercury Sable can be a problem pulling out of a stop sign or a toll booth in the rain. I can't take off as fast as I do on a dry day. When I had the 300HP 1996 STS, you had to go easy on the gas because once the traction control kicks in, you take a significant hit on acceleration.

Also I test drove a 2005 V6 STS (rather aggressively; isn't that expected?), and got a bit of a surprise in getting the rear to break loose accelerating from a stop into a left hand turn.

With AWD, I don't worry about any of this. If I want to take off quickly in wet, or dry, I just put my foot down and the car goes. Traction control doesn't take over. It's very nice.

[eightshb]

My 05 has STS4 in the corner

[shudog]

Got about 3" of snow here in the Detroit area last night and I-75 didn't look like it had been plowed or salted. Every time I tapped my brakes the ABS came on. What was in front of me? A new C6 Vette... just thought that was great while we're all discussing tires & traction & awd....

[Caroutisine]

Knowing what I do now about these cars, I would have paid for the AWD.

[Slo-Mo-Shun]

Originally Posted by AllWheelEric

On a 2WD car, it's very easy to get the drive wheels to break loose in the rain. Even my 200HP Mercury Sable can be a problem pulling out of a stop sign or a toll booth in the rain. I can't take off as fast as I do on a dry day. When I had the 300HP 1996 STS, you had to go easy on the gas because once the traction control kicks in, you take a significant hit on acceleration.

Also I test drove a 2005 V6 STS (rather aggressively; isn't that expected?), and got a bit of a surprise in getting the rear to break loose accelerating from a stop into a left hand turn.

With AWD, I don't worry about any of this. If I want to take off quickly in wet, or dry, I just put my foot down and the car goes. Traction control doesn't take over. It's very nice.

I think you're overstating the case. Not counting closed-course racing, in 35+ years of driving I can't recall one situtation where a momentary loss of traction while accelerating in the rain put me in any danger.

On the other hand, carrying around 300 lbs or so of extra weight from a 4wd system, some of it rotating mass, can't be doing the brakes any good. Add in a bunch of corner-entry understeer inherent in 4wd and the general reduction in ultimate cornering g's that's going to come from loading up the front end of the car with extra weight, and I find the alleged safety aspects of 4wd in anything other than extreme, traction-critical conditions to be suspect. Braking and ultimate cornering are being sacrificed for traction/acceleration.

I'm not questioning anyone's decision to go with 4wd, as most of you probably see more ice and snow than I do. But a realistic evaluation has to recognize the negatives of 4wd and factor them in. There's a trade off going on here.