avs007

I used to give my room-mate a hard time about that. Saving his $50 brake pads by sacrificing his $1700 clutch. (The amount he paid later in the year for a clutch job)

Although, when going down a long downgrade, it's good to engine brake, but only to maintain speed, not to actually slow down.

Legend2TL

http://www-nrd.nhtsa.dot.gov/vrtc/ca...T4FinalRpt.pdf
Pretty good study by NHTSA on ABS effectiveness

http://www.samarins.com/glossary/abs.html

For loose snow or gravel ABS stops are longer for light vehicles, for all else ABS stops are shorter. For packed snow and ice there is some debate out there but most of research shows shorter stopping distances are with ABS.

The point of the original discussion was mantaining control on slick surfaces, the brakes are easier to modulate and control than using the engine which has awkward and non-linear control for braking forces. In a slick surface situation, it is best to use the brakes to modulate and control the deceleration forces on the tires.

geekybiker

Well, assuming you have someone who just mashes the pedal that might be true. A good driver can outbrake ABS even in optimal conditions for it. The unfortunate thing about ABS is most drivers never activate it until they actually are in a panic braking situation. When the pedal stats pulsing they often think something is wrong with their brakes and ease up on them.

My main issue has been the cases where ABS has activated in error. Ie undulating or broken pavement. Ive had ABS come on and not let me have the brakes untill almost too late.

That said, for most drivers and most situations its a good thing.

Legend2TL

I agree on the use of ABS, polling data still shows most drivers do not use it or unaware how to use it effectively.

In terms of the shortest stopping distance, when ABS came out that was true. Early ABS systems (even the quality ones from Bosch) were not as good as a good driver in providing the shortest distance in the dry, the wet was often a tossup. The problem was how many times per second the ABS system could detect a locked wheel and make appropiate action. However the ABS technology for the controllers and their firmware has been improving dramtically in the last two decades. Some of the latest ABS systems can measure a wheel lock/slip every 6" (Ferrari F430) and can control the brake pressure modulation into hundreds of times a seconds. And on poor pavement (snow, ice, ...) the early (keyword here) had longer stopping distances. Again as DSP chip technology has made mobile phones smaller and more capable, it has done the same for ABS controllers along with much better firmware. In addition some modulators (like the Delco VI series) do not use solenoids but servo motors to release and apply brake pressure so the modulator is not simply digitally controlling the brake (i.e. pumping the brakes) but using analog-like controls to mantain as high a stopping force as needed.

A few years back Car and Driver magazine did a dry ABS versus non-ABS stopping test with a BMW 325i, the ABS systems were shortest in the dry and wet even compared to their test drivers.

One of the unfortunate things about ABS is that no specifications are published for the car in terms of measurement frequency and modulation control frequency. Most manufacturers do not publish this info, a decade or so ago BMW had ads saying how their ABS systems were far improved over other manufacturers ABS systems. People tend to think all ABS systems are created equal, a Porsche Bosch ABS controller is far superior to the system put into a Toyota Camary.

evantec

Assuming snow tires are better than the all-seasons in the TL, next question is about transporting them.

I don't own a torque wrench, so if I got snow tires I'd have them put on at a garage or tire-shop. But then how do I get the regular tires home? I don't think all 4 would fit in the trunk. Do I muck up the back seat or bag them? Or do I have a spouse or friend follow me in a minivan SUV or pickup truck carrying the tires. (It's starting to look like the trailers that carry the equipment that goes with a race-car.)

I'm not trying to be sarcastic - I was just wondering what most of the tire-changers do. I figure a bunch of people probably have jack-stands and large garages, but for the rest of us... ?

geekybiker

I have a jack and a very very very small garage. The Tl's tires arent that big though. They should be able to fit in the trunk. The tire shop should provide plastic bags for them.

evantec

Thanks!

Sometimes tires look pretty large at the tire shop, and the car trunk looks small when you go to put something in it!

rec

We've got the transportation questions answered which had also crossed my mind...now what about suggestions for storage? I''ve considered snow tires for my 06...haven't driven in snow yet, but read all the stories on the forum...but I rent an apt and have no garage. Pretty sure I don't want the A/S tires doing duty as a make-shift end table in the living room or bedroom :-) Can't think of anyone I know with a garage with space to spare and I don't think I want to rent a storage unit just for the tires. Someone told me some tire shops have a storage plan for your tires if you buy their tires, but haven't tried calling any to see if true.

Thanks

JERU

Two tires in the trunk, two in the back seat. Heavy plastic bags that close so the tire does not slide out and mark your back seat. Those tires are 17", very large..

avs007

People keep saying the G35 is smaller than the TL.... So If you can fit 8 18" tires in a G35 Coupe then certainly it can be done in a TL too

groovyone789

just make sure you pull out the spare and its cover and use that compartment for another tire

mu1980

Glad to report that the significant snow we had in WI yesterday was not a big issue for me with the TL. After work, I got out of my parking spot just fine even though I was kinda plowed in.. with 1' drifts on all sides and the ride home across town was just peachy with slush and snow-packed roads. No sliding, no trouble getting traction to start moving from a stop.

avs007

1' drifts, that's not snow This is snow (just playin')

CometVR4

ABSs' main purpose is not to stop shorter but for the driver to Maintain steering control during a panic stop whereas it pumps the brakes 100X faster than a human plus it can do indivual wheels. As someone mentioned earlier it can lengthen the stopping distances on some surfaces but you still have some steering control.

And using the engine to slow down on AWD doesn't help. I tried that before when I got caught in a snow storm in my AWD 3000GT 6-spd. I downshifted to second and slowly lifted off the clutch. All four wheels locked up... The car went into a four wheel drift. I didn't have any steering control or anything. Luckly I pushed the clutch in quickly to get the wheels rolling again and just stop on the threshold of ABS engaging. But for those couple of second was scary as I wasn't on the brakes and my wheels are locked up.

mu1980

Haha.. yeah, you guys in the Pacific NW got socked. From what I understand, that's just a freak occurrence, though. The kind of snow we got around here (caused by the same storm that brought you all of the snow pictured) isn't all that uncommon. The other difference is that your snow will probably melt quite a bit... ours will be around until spring.

ubnpast

What kind of tires did you have? You have to have strictly snow tires for it to work. How fast were you going? I had a 94 vr4, and was going about 20mph and the people in front of me stopped for a red light, I revved and put it into 1st, if I had not done that, I would of hit the people in front of me because of the ice under the snow.

It all depends on how fast you are going, what kind of tires you have, and what gear you put it into for downshifting to be more effective than abs.

groovyone789

we got a foot of snow this friday, didn't drive my car all morning (went around in a friends ML) then took it out in the afternoon. Handled fine in the barely plowed roads. Amazed that I never really slipped while accelerating. My ABS never went on during any of my braking on ice and everything. (probably due to new tires). The only time i'd really slip was trying to turn, i'd start to fish tail, give it a little gas (cuz my front wheels held well) and even out. it was actually pretty fun. The only thing that'd be nice is a little more ground clearence. It's scary going over snow mounds from stupid plows. At least I knew it wasn't ice yet.

Another thing to note; make sure you clean off that right foot really good before drving around. Aluminium Pedals + Ice/snow shoes = fun time. At least the brake pedal has rubber grips.

avs007

I call bs. Engine braking will slow you down, but it will not slow you down faster than slamming on the brakes. If you don't believe me, go do some 60-0 panic stop tests, using the brakes, and engine braking.

Explain to me how engine braking will slow you down faster, I'd like to know.

ubnpast

Holy shit, someone cannot read. When I said I was driving my awd 3000gt which weighed 4000lbs, I had snow tires on it. I said downshifting in snow really helped me out better than slamming on the brakes because of the ice and snow.

It helps under some circumstances, and out performs ABS in some circumstances. Imagine going down a slight hill, you slam on the brakes, due to the ABS locking and unlocking each wheel (in the snow) your pedal jumps which is normal, but the tires cant get traction on the ice and snow by locking and unlocking so fast.
Now your going down the same hill same conditions and have to stop the same way, by downshifting the tires actually grab the snow and ice better because they are not constantly locking and unlocking, but are turning freely with the transmission at a slower speed, which slows the car down.

I am tired of explaining this to people who dont believe me. The fact is that it worked for me, and if it doesnt for anyone that had in fact had their own AWD car and driven in the snow themselves (your friends dont count because you are not controlling the car) you are not doing something right. If you do in fact have a AWD car that you drive regularly, come over to my house, I will prove to you that it actually outperforms ABS in tractionless conditions.

sbasaria

I live in the second coldest capital city in the world, Ottawa, Ontario, Canada only Moscow beats our average winter temps! I am on my second season with the TL-S 02 and use Toyo winter tires 16s and find the car to be good/average in the snow. Sometimes around corners it slips a bit but that can be expected with the weight of the 260 hp engine I am sure. cheers!

avs007

More like somebody cannot remember what they typed

Sounds like you said that if you hadn't downshifted, ABS would not have stopped in time. Hence you are claiming downshifting allowed you to stop faster.
Traction is traction, doesn't matter if the force is coming from your engine or your brakes. Only difference between ABS and downshifting, is what happens if you exceed the traction limits of the tires on any given surface. ABS will pulse the brakes. Downshifting, you may end up sliding out of control.

Again, I call bs. If you have awesome tires that allows it to "grab" the snow/ice without locking up, then it has enough traction to allow you to hit the brakes without them locking up too. After I got new tires on my other car, I even tried slamming on the brakes on the hill by my house in the snow, and the ABS did not engage.

If there is enough traction to allow the sudden change in speed without causing the tires to slide, then you could've hit the brakes without engaging the ABS.

Fact is, you are assuming that the ABS would've engaged had you hit the brakes in the same situation. 99% of the time, using your brakes to slow down is the safer thing to do. Especially considering that even if ABS is whacking out on you, you could still try to steer around whatever it is you are trying to avoid. If you downshift because you think you may stop faster, but then enter a 4-wheel slide, you'll probably have no hope of steering around it.

If you are in a tractionless situation, how the hell is downshifting going to slow you down? You need traction to slow down.

ubnpast

You had never owned nor operated an awd car in the snow, so first off I would like to tell you to eat shit .


I certainly can remember what I type, its idiots like you that make me remember.

Wow you can comprehend the first part, idk what happened, maybe you have a frost bitten brain?. Traction is traction yes, but you will get better traction if YOU (which you currently dont) know how to complete the task the right way.

Go try that with awd on snow and ice, and have a car that weighs 2 tons. Wait, thats right you dont have one .

I guess its people like you that never been on snow or ice, you people cause all the accidents which lead to higher insurance. Lets just feather the brake pedal when people in front of you are stopped...


The fact is I know how to drive a car, and what makes me so good at is that I can predict what it will do next, instead of waiting to see what will happen .

Here is something you do not know, with awd all tires turn at the same speed. So all tires are slowing down at the same speed.

Get a life.

avs007

How does the coefficient of friction between the tires and the pavement change depending on if force was applied using the brakes or the engine? If you draw an arrow representing the force of the ground being exerted on the tires and vice-versa, there is a limited amount of traction that the tires can sustain. Whether you apply force by hitting the brakes or downshifting is irrelevant. As soon as you pass that threshold, you will skid the tires.


See above image.

You mean people like you? We have brake lights for a reason I'd like to see you try to swerve around a kid that bolts out into the snowy street by downshifting and entering a 4-wheel skid.


Unless you have a locker or perhaps are in an SUV, all tires do not necessarily turn at the same speed. If they did, then how do you turn, when the inner side of your car is traversing a smaller circle than the outer side of your car? But that's beside the point. The fact that all wheels are slowing down at the same rate is irrelevent when talking about how fast you are slowing down your car. What's important is how much kinetic energy you are converting into heat. With brake-force distribution, the brakes do a wonderful job of trying to spread the load to all the wheels. You said yourself that you have to have really good tires for your scenario. If you have really good tires, the ABS may not necessarily engage anyways. And if you had such poor traction that it does engage, then downshifting will result in all the wheels skidding as they spin slower, but there isn't enough friction with the ice/snow for the ground to match speed with the rotational speed of the tires.

ubnpast

Speak english much?

Brake lights dont let you stop any faster, and I never said anything about swerving in snow, learn to read dipshit. You dont skid either by downshifting, you may for a split second loose traction, but the traction you gain is far better than abs. A 4 wheel skid is if you dont have abs or are sliding sideways, downshifting in a straight line will not make YOU skid.


I dont need one, I forget what kind of differential my old car had, but it acted as if it was a locker.

What does a suv have to do with anything?

Thats why they make all different types of differentials.

What planet are you from? You certainly are not from around here, because you dont know what you are talking about.

Yes, key word "trying"

Well I have never driven without snow tires, so I cannot say anything about other tires.

[QUOTE=avs007]If you have really good tires, the ABS may not necessarily engage anyways.

The abs willl come on when the tires are on icey snow if you really stepped on the brake pedal.

The wheels would only have a loss of traction for a split second, nothing compared to abs. If there is snow and ice on the ground, the slower spinning tires will scrape it up, sometimes enough to touch the road sometimes not.

I am done replying to your uneducated comments, I do not feel like wasting my time, especially when trying to aregue with you, which you do not even know what you are talking about. Good for you with your g35, just because you own one does not mean you know how to drive it.

Legend2TL

http://auto.howstuffworks.com/four-wheel-drive.htm

from this link
" There are also some situations in which four-wheel drive provides no advantage over two-wheel drive. Most notably, four-wheel-drive systems won't help you stop on slippery surfaces. It's all up to the brakes and the anti-lock braking system (ABS)"


Seriously for your own good Google "tires coefficent friction ice snow dynamic static", read some of the links that explain physics and how vehicle dynamics and tires work and educate yourself.

leedogg

PeterUbers

iTrader: (1)

I drove the G35x in the snow (my sister-in-law's brand new 2006) .. and IT ROCKS!!

My Aspec TL is "ok" in the snow .. beats the hell outta RWD. The G35x has a kewl feature where you can split the front/rear power 50/50 in very bad conditions .. gets you out FAST.

My VSA actually kicks in once in a while (the yaw-control component of VSA, that is) and it's cool to feel the outer corner wheel braking to "swing" you through your turn... me likey.

ubnpast

Ok, you want some too ?

They are referring to 4 wheel drive in that article, not awd.
http://auto.howstuffworks.com/framed...//www.iihs.org

massr1

WTF does it matter?? Why don't you understand the physics of a vehicle stopping? All wheels with power doesn't make you stop sooner, it only helps with acceleration.
You are arguing with this guy and totally getting owned with your own remarks.
And btw, letting people behind you know your slowing down by tapping your brake is a good way to prevent an accident, especially in bad weather.

ubnpast

I said that because the article did not state whether the 4wd was in fact engaged.
And your what 18? How long have you been driving? I bet you really know how to drive your parents car, huh?

avs007

Excuse me for transposing the word order What's the point about arguing about grammar? You obviously knew what I was talking about.

You think I can't read? I never said they do. You were the one talking about safety. I would think you would want to let the folks behind you know that you are trying to slow down. I bet next you are going to twist my words around and claim that I'm arguing that yellow foglights help you stop better in the fog.

You were talking about safety, and how it's safer to downshift. If you're talking about safety, needing to swerve is a factor. Otherwise I could argue that it's better to have slicks on, to get better traction, despite the fact that you may want to have traction in the wet/rain/snow/etc. Just becuase 1% of the time running slicks gives you maximum traction, doesn't mean that it is the preferred tire in daily driving. Just like downshifting is not the preferred way to slow down in the snow.

Not true. As soon as you pop out the clutch, the engine will place drag on the wheels, and the wheels will want to run slower. If there isn't enough traction, the wheels will start sliding because there isn't enough traction to transfer this force to the ground. As soon as your front tires start sliding, you have zero directional control. Especially if you are going down a hill, once you lose directional control, you can enter a spin and start sliding at an angle or even sideways.

Many SUV's don't have manual lockers, but allow you to electronically lock the center diff.


Might want to pick up those physics books again. Just because all wheels decelerate at the same rate, doesn't mean the car will slow down faster.

What's the point in differentiating that? Brake Force Distribution spreads braking pressure based on load, etc. Engine braking (with a locker) simply spreads the load 50/50. Why would you want to spread the load 50/50 when most of the force is needed on the front 2 wheels? You're going to end up with 50% braking power on the front, and some wasted braking power in the back. Especially when going down a hill.

Why only a split second? Loss of control is loss of control. That's like saying somebody is just a little bit pregnant. In that split second that you are out-of-control, you can start sliding sideways, etc. A slower spinning tire may push the snow, but that doesn't mean it will reach the ground. Most likely it is just going to compact the snow even more.


I think most would agree that your comments are the ones that are most off base.

That's a weak/silly argument. When talking about 4WD, and the benefits and such, why would they mention this if the 4WD is not engaged? That's like me pointing to an article saying condoms are only 80% effective, and then you saying that the article didn't say the person was actually wearing a condom.

avs007

Just because somebody drives for 30 years does not make them a better driver than somebody who only drove for 10 years. That would be like me trying to argue that I'm a better golfer than Tiger Woods or Michelle Wie.

Legend2TL

avs007, I commend you for trying to explain the laws of vehicle dynamics and physics to others in this thread but I feel as if we're trying to explain that the world is round in 1492. Let them believe it's flat.

ubnpast

So someone who just got their license is going to be a better driver than someone who has been handling their car and other cars for 10+ years?

ubnpast

Since 99% of you never had a awd car, I posted my question on the forum for ad cars I have recieved these replies:
If anyone feels the need to argue my point any further please PM me, I am not going to keep posting on someones thread who just asked how the performance of the tl was in the snow.

avs007

Your logic is a little off. I did not say that. I said just because you have been driving longer, doesn't automatically mean you are a better driver. I didn't say that everyone that has less time behind the wheel is a better driver.

That's like me saying that all squares are rectangles, and then you try to say I'm wrong because this rectangle is not a square.

avs007

I could make the same argument that 99% of the people on that forum have never stepped into a physics class. Would you think I'm smoking crack if I told you the Earth is closer to the sun when the northern hemisphere is experiencing winter rather than summer?

I've seen many people try to argue that fraternal twin occurs when one sperm fertilizes two eggs.

And who "proved" that ABS is worthless in the snow? Go to munich, and go to the Deutche Museum. There is an exhibit there on ABS and VSA. One of them even has a demonstration of a Mercedes Benz with ABS on and off driving on the snow. It clearly shows that ABS does in fact provide benafits on the snow.

Did you know that static friction > kinetic friction? If you understood that, you'll understand why ABS works the way it does, and why letting go of the wheel is preferable than allowing it to skid.

Car and Driver even did a test (many moons ago) of various tires in the wet with/without abs. When comparing the same tire, in every test, ABS outbraked non-ABS. However, when comparing across tires, some tires were able to stop faster in full lock and slide than other crappier tires with ABS. However, same tests of these tires, showed that they still stopped faster with ABS.

Sure, under perfect circumstances, a sliding tire may gain extra drag-friction by pushing a pile of snow, and that extra traction combined with the decreased traction afforded by kinetic friction, may be greater than the static friction. But that doesn't mean that is always going to be the case.

avs007

Just to add, I see you are from NJ. Just because you have to be 18 to get your license in NJ, doesn't meant the rest of this great nation is the same. Many states allow you to drive when you are 14 if you live out in the country. Otherwise it's usually 15 or 16.

avs007

Read this.

If you're too lazy, let me quote an excerpt:

avs007

Just in case you think that site is biased, here are a few more:

Another site
Yet another site
How about one more site?
Nah, here's another one
Just one more