First drive in snow probs: Tires, I hope...ABS brakes frightening

Really? Then you are a fool if you think you can do a better job than Audi ABS brakes. Take one of the schools I suggested. They will test you with and without abs. I guarantee you can not do several of the exercises in the school without using abs. You'd crash - but not burn, thankfully. They'll have you do one of the exercises with abs. If you can match the same results *without* abs, you should be driving professionally, not wasting your time on this ng. Dave

On dry pavement, ABS is not quite as good as a really experienced driver. Optimum braking is achieved with about 10% tire slip, which ABS systems will not let you achieve. On wet or icy pavement, ABS will do better than 99.9% of drivers, no matter how experienced.

Does the phrase, "Jack of all trades -- master of none?" seem to fit here?

Grover, I appreciate your kind approach, but I must agree with Dave here. There is clearly a psychological aspect to this.

I am, in fact, an excellent driver and am quite capable of threshold braking. I don't buy that fact the real world average drivers in real world situations are better off with the ABS system. The "freak-out" factor is simply much too signicant.

Regarding ABS equipped heavy metal. If the only time cars had to brake was upon landing on a 7000 foot runway at a gross weight of many tons, the analogy would have some merit.

Yes, I understand the physics are the same. The scenarios are not. Dave

No, still not buying it, not for real world average driving shlubs in real world situations. My wife is driving a new Mazda with ABS and it freaks her out every time. Differentiate between scientifically minded drivers like you an me and the average Jane or Joe.

Perhaps I should be driving professionally. If ABS were defeatable on this A4, I'm certain I could outperform it every time.

ABS is simply too counter-intuitive. It is unbearably unnatural. Of all the mechanical devices ever invented, clearly the automobile is a contrivance that most intimately exists as an extension of the mind/body complex. save that of a instrument such as the violin. ABS short circuits that relationship in an intensely artificial fashion.

Dave

Ok, so you don't.

Braking and steering with ABS can be more easily learned than braking, opening the brakes at the exactly right time, steering clear of the obstacle and reapplying the brakes.

I can just tell from seeing 20 people in handling training that all 20 were just having a much easier time keeping their car under control.

These handling courses are closed circuits on which you don't go fast but they have wet, slippery surfaces, water walls, simulated surprising obstacles, braking uphill and downhill and, most interestingly different friction coefficients on the left and right side of the vehicle.

I had the chance to try an Audi 80 (non quattro) at that time with the ABS on/off switch. On this specific course with the slippery roadsurface under the right wheels and the standard surface under the left wheels the difference was remarkable.

With the ABS off, you had to brake hard. On the slippery side the tires would lock and the car would veer off course, starting a spin, because braking would only be performed on the "dry side". So you had to open the brakes, adjust direction and then slam on the brakes again. A very delicate procedure.

With ABS "on" the car just stayed on course and you could brake for the whole time.

I consider myself an average driver with some additional training on cars and reasonable track experience on supersport motorcycles (no ABS there ;-)). Still, using the same car, at the same time on absolutely comparable surfaces with the same driver and the same starting speed (~80 km/h) I stopped the car at least two lengths earlier using ABS. And with much less work on the wheel and the brakes, I can assure you. You could hold the car straight with just one finger on the wheel while with the ABS off you had to really work hard.

Again, it's the ability to control the car all the time which gives the big advantage.

_All_ participants of the training course claimed that their next car would have ABS. And if they would have to decide between ABS and air condition (price wise) it would be the first.

Then just pull the fuse and do so? Or get a car without ABS?

Regards

Wolfgang

Good post, Wolfgang. At the school I used to help teach, one of the demos done by an instructor to emphasize abs advantage was to drive the car down the track at 60mph. With two tires (right side) on the grass or dirt and the other two (left side) on blacktop, the instructor would *jump* on the brakes as hard as he could, and then remove his hands from the steering wheel. The car *always* came to a straight stop. Try that *without* abs and I'll guarantee the average driver without any racing/driving school will lose control. The demo was done not to illustrate how easily the car stopped, but to visualize what was happening on the right side (less traction side) during the emergency stop. At every revolution of the right front wheel you could see the "hesitation" just before lock-up. There would be little piles of dirt (a couple of inches long) or the grass would be up-rooted for a couple of inches.

ddhartwick's problems with it is probably typical of anyone who does not know what abs is capable of doing. What you intuitively do when braking with non-abs is to try not to lock them up (if you know how to do it), while what you do in an abs car is simply jump on the brakes as hard as you can - don't modulate or pump them. They will take what they need to stop the car.

Once again, I invite hartwick to take a school that teaches abs vs non-abs braking. None are so blind as to refuse to see. Such a school will open his eyes and more than likely save his wife from a bad accident. He may think he can beat abs in an emergency, but the only way to tell is to do it Dave

You're correct, Dave, that in *most* unusual, low, or (side-to-side) differing traction situations you can name, ABS will save your butt. OTOH, you should know as well as I do that it's not all *that* hard to outbrake it on a regular dry surface. I know I can (admittedly, not by a lot). However, *most* of our driving is on exactly that type of surface, so *most of the time*, I can outbrake an equivalent ABS-equipped car. Then, there's the other extreme of surfaces where it's particulate like snow, sand, or gravel where piling up a bit of the crud in front of your wheels is the fastest way to stop. This is where I miss the switch in my older Audis.

For the *average* driver, I totally agree with you. ABS effectively gets them *pretty close* to threshold braking - but it's not, nor is it quite *as good as* actual threshold braking. We both know that. We also both know that, if conditions are anything other than ideal, the *accomplished* driver will understand and appreciate what ABS can do. I think this is our original poster's problem. He just isn't used to it yet and he hasn't quite figured out that the STOP sign he 'ABSed' through was one he was going to

Agreed.

-- C.R. Krieger (Been there; done that)

I agree. I've also done it. I don't think that the original poster knows how to do either, however. He has simply made up his mind that abs sucks, while you and I know it doesn't.

Then, there's

Yeah, but that is only in deep snow. On a plowed surface, I'll go with abs. When Joanne and I used to rally, we had Audis with an abs switch to turn it off while on dirt/gravel roads. Which reminds me: when I was invited to review the first Corvette with ABS, they had jury rigged an on/off toggle switch on the center console. I did a couple of exercises that required threshold braking and steering. It was much easier (no brainer) with the abs on. It could be done (by many) without the abs, but abs made several new friends on that day, especially those who failed ("crashed") the exercise without abs.

Probably correct. I had friends that bought abs cars in the 80s. When I asked them if they tried it, they said they "didn't know". I convinced several to take their cars on a out-of-the-way road on a rainy day and jump on the brakes. Again, it was an eye-opener. Most said they took pressure off of the brake pedal when they heard the brakes and felt the kick-back on the brake pedal. Of course when they actually felt the abs under an emergency condition, they knew enough *not* to take their foot off of the brake.

I believe it was the Ohio State Police that had several accidents when they first equipped themselves with abs Chevys, maybe even a fatality. They contacted GM and claimed their brakes weren't working properly. Again, it was lack of training, lack of "what to expect", when applying abs in an emergency.

I think it good advice to those reading these words to experience exactly what happens when abs is employed. Experience it safely off on some side road so that you will know what to expect when you experience them in an emergency. Also note that you can steer during full braking. You *can* steer away from hitting the guy in front of you.

Dave

Your wife shouldn't feel her ABS unless the tires were entering a state of skidding. THAT would have really freaked her out. The first few times you feel the noise/pedal feedback it can be disconcerting, but it is better than the alternative. I think you're overestimating the traction of your tires when you think you could beat the ABS. RE950's have an agressive tread pattern and appear to have no siping. Not good for snow. All weather/all-season is a joke of a classification. I've driven on RE92's (all-season) that weren't awful when new, but got noticably worse each winter. Those were replaced by Dunlop A2's (all season) that were much better in dry and wet. However, in the snow they were barely divable the first winter. The second winter, they were sled runners. I swear i would have been better off with racing slicks. My wife has an accord and has had various Michelin tires on her car. All have had considerable siping for an all-season and they were the best all-seasons i have driven in the snow. Having said that, we both have dedicated snow tires now and they are head and shoulders above the best all-seasons. If you want to stay with an all-season tire, try to find one with a more suitable tread pattern than the RE950's. If you want to know what works well in the snow, look at a snow tire. Block tread pattern, siping everywhere!

Stu

I think you hit the problem on the head here. I think the problem is more his tires than his brakes.

Stu

That was established very early on, Stu. He's driving with all season tires. If he really wants to stop, he needs snows. Dave

It's also worth bearing in mind that the early systems would often release all four wheels if all locked at the same time.

I've had it happen on a Rover [Sterling] 400, and it wasn't very pleasant. (An idiot shot a red light and came at me on the wrong side of the read). IIRC system fitted to BMWs simply kept all four wheels locked (not as effective as working ABS, but a helluva lot better than having to fully release the pedal and try again..)

Modern systems are much better, and EBD gets around the reaction of a driver unfamiliar with the system (although, on my TT, it did appear to generate a little lateral instability when I tested it)

H1K

EBD is only front/rear brake force distribution like the old thing on the rear axle but now electronic. It does nothing more.

Ronald

Is Hairy thinking of the system (pioneered by MB?) and called something like Electronic (or Emergency?) Brake Assist, which attempts to determine the level of panic when pressing the brake pedal and, above a certain level, automatically applies maximum braking effort?

Thanks, Peter - precisely that (Electronic Brake Distribution)

It sharply ramps the braking force (with ABS engaged), just in case the driver gets hesitant. It is entirely unrelated to the pressure valve used to prevent the rear wheels locking before the fronts (thereby inducing a spin. And, believe me, that's perfectly feasible - I had a nasty tank-slapper once on a new Citroen with a "pre-failed" unit). It's also the reason why, if one only buys two tyres, they should always go on the back, rather than the front. Oversteer can be fun. Reversing into a tree at high speed is expensive, at very best ;o)

Back to the TT: this also gives a slewing motion as each wheel adjusts to the local surface conditions under its own tyre. I wouldn't like to even try and steer in any particular direction when it's activated, ABS or not! It's enough to keep it in a straight line.

Probably less obvious on a car with a greater length:width ratio.

TBH, I've no idea how much /actual/ road movement it induces, but the acceleration /feels/ significant - akin to an unexpected breakaway on a bend.

H1K

'bellfamily')\\

That's called Brake Assistant in Audi cars.

Ronald

Exactly--fatal accidents due to ABS. It is not unreasonable to assume that psychological factors--lack of knowledge, startle factor, lack of intuitively correct feel, etc., probably greatly overwhelms ABS advantages that are only theoretical unless in the hands of guys like you.

Aditionally, How often do people brake AND steer around the car their about to crash into? Some do, I do, many don't.

I do know how to threshold brake, fwiw, but you guys are obviously more skilled and knowledgeable than I.

Finally--I must stress that I hope you're right, that ABS is superior. I don't want to own a car that has permanently crippled brakes. Dave

Snow--tires....there is no getting around it.

I do not understand this sentence: "I think you're overestimating the traction of your tires when you think you could beat the ABS."

Dave