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winter driving factors

Posted by jaffar 
January 08, 2009 08:42AM
In the past days my oppinion towards BMW (at least old ones) has changed for worse, while at the same time my oppinion for cheaper cars has changed for better. Why ? Read...

Finally, it's winter, time to have lots of fun with my BMW. It's also my first winter driving a LSD. Sure, the car slides a lot and I'm having a great time with it... BUT... what if I want to just drive on a road, even on a twisty mountain road ? Well, then I can only accelerate very very slowly (otherwise my car is all over the place), I have to take all twists very very very very slowly and if the road is gong down and I need to brake, then it feels like it will NEVER stop. I have winter tires (Vredestein Snowtrac2), 15" wheels, width 205, Bilstein B6 Sport shocks and everything in the suspension is new. I don't have ASC, only ABS.

Then I take my g/f's car, which is a 2008 Opel Astra 1.9 diesel (so lots of low end torque), completely stock, with the same type of winter tires, only in 16" size (same 205 width). It also has ESP. With this car, I can be as brutal as I want, nothing funny happens. I can floor the throttle pedal, the ESP light just blinks once or twice and the car doesn't slide AT ALL. It also stops very fast when pushing the brakes. A completely different experience. It's not as fun as the BMW, clearly, but it's a lot safer.

Then I take a friend's car, which is a 2006 Hyundai Sonata, 2.4, gasoline, ESP, 17" winter tires Vredestein Wintrac Extreme, width 225. Huge beast, but with a lot of nerve. Now, this is very upsetting: this car doesn't care that it's winter outside ! It runs at redline, the ESP barely blinks, you can do almost anything with it. For some time, I really thought that the driver has a deathwish, the way he drove it ! But then I tested the car and the conclusion was clear: the car allows you to drive like an idiot smiling smiley

So, now for the conclusions: what makes a car perform SO DAMN well ?

- the driving axle - front or rear
- the tires
- the size of the tires - width or diameter of rim
- the electronic systems (ESP etc)
- the driver (i tested all three so i couldn't say if i was a better or a worse driver on some of them smiling smiley )
- the weight
- the weight dirstribution
- others ?

Please share your thoughts and your experience. I'm considering upgrading to FWD at this point.

Thanks

--
A physics truck just turned over outside. There's physics everywhere!
January 08, 2009 09:09AM
Quote
jaffar
what if I want to just drive on a road, even on a twisty mountain road ? Well, then I can only accelerate very very slowly (otherwise my car is all over the place), I have to take all twists very very very very slowly and if the road is gong down and I need to brake, then it feels like it will NEVER stop.
That's not normal. That is dangerous and abnormal behavior for any car, FWD or RWD, LSD or not. It's not because it's a BMW. Something is wrong somewhere. It's hard to say exactly what without more information. I'll start with the tires: How old are your winter tires? Usually winter tires are only good for about 3 winters, maybe 4. How many miles/km are on them?

__________
Dave
'91 325iX
January 08, 2009 09:29AM
my tires are on their second winter. probably no more than 1000 km onboard.
hyundai's tires have the same age.
opel's tires are new.

--
A physics truck just turned over outside. There's physics everywhere!
January 08, 2009 10:45AM
Well, a big part of it is the ESP. I never had trouble driving my e30 in the snow, even with some pretty beat up performance tires (I did have two 45lb weights in the trunk) but you have to be gradual with speed changes etc. On the other hand, I was driving my e60 545i the other day with DSC and it is like the other cars you describe. You can just slam the pedal to the floor and the DSC will take care of it. Those cars probably start off the line a little better with FWD than the BMW, but the RWD will give you a lot more control if you know how to use it. What is really happening though is that it feels so much safer because the esp is already doing the work. You don't realize it, but when the light is blinking it is making thousands of calculations and modulating individual brakes and throttle etc. to keep the wheels from spinning.
January 08, 2009 12:39PM
Quote
jaffar
I'm considering upgrading to FWD at this point.

That's a major downgrade!!!!!

The best car I've ever driven in the winter, hands down, is my E30 (with Blizzak snow tires and LSD). RWD gives you independent control over both ends of the car. With FWD, if your front wheels start to slip, then you are totally out of luck; you can't accelerate, steer, or stop. That's not a good thing. And if it's very slippery, just the slightest bit of torque will set the wheels spinning. With RWD, the front wheels can make use of every bit of available traction to turning and stopping you, without the worry of power-induced slippage. Obviously you can still slip, but not because of any torque you put into the drivetrain. RWD lets you steer the back end and the front end of the car.

The worst car I've ever driven in the winter is my FWD Mazda3 (2.3L gas engine) with the no-season tires on. A storm took us somewhat by surprise this year and I didn't have a chance to put on the snow tires. It was brutal. OTOH, once the snows are on, I have never had a problem, but I still don't like the way the car handles in snow nearly as much as the E30.

Our AWD E46 is almost as worthless in the snow with no-season tires as the Mazda3, but a little bit better. I really dislike the DSC, b/c as soon as it detects any slippage, it cuts the engine power and you are at the total mercy of the slide you've started. Then if you disable DSC, the open differentials hardly let you get moving at all. I went ice racing once with the E46 (with snow tires) and it was horrible. I either couldn't get moving with DSC off or I would get moving but then lose control as soon as the engine cut out during a slide (which happens most of the time when driving on a lake!).

With the snow tires, the E46 is a pretty stable car to drive in the bad weather, but I would much prefer having the front wheels unpowered so they can devote their entire traction circle to steering and stopping, which is all that God intended front wheels to do!

I can't explain why your car was so lousy in the snow compared to the others, but it certainly does not agree with the experiences I've had with winter driving of various drivetrain setups.

Cab
1990 325i(s)
2004 325XiT
January 08, 2009 01:46PM
Is your car lowered? Has it had its camber changed? I wouldn't run too hard shocks as well.

My E30 has an open diff, which makes it a bit harder to make a start in slippery conditions, but once rolling it is a joy to drive. Be easy on the throttle and induce just a little wheelspin.
January 08, 2009 04:04PM
I agree that the difference is largely due to the ESP. Those modules are manufactured at a plant near me. I have seen some very interesting demo videos showing performance of a car with and without ESP on snow. It is amazing. I would not buy another car without it.

Andy
1987 325ic
January 08, 2009 11:49PM
I noticed with my 325iS, its easier to start but once you're going its actually not as safe as having an open diff, because when i had my 325, if i gave it too much gas only one wheel would spin and the tail wouldn't go anywhere, but now i have to be more careful, but then again i don't have to worry about that when i have ASC on smiling smiley
January 08, 2009 11:53PM
On a more useful note, my car was driving really whacky in slippery conditions, can't really notice it when its dry, but when its slippery the car felt like it wanted to dog leg, i found out just recently the one of my rear wheels was significantly toed in more than the other, i'm still waiting on it to get an alignment, i'll let you know how big of a difference it made, hopefully huge.

BTW I am not a newbie lol, it's not my fault my account was gone haha!



Edited 1 time(s). Last edit at 01/08/2009 11:54PM by Andrew.
January 12, 2009 09:42AM
Quote
Andrew
once you're going its actually not as safe as having an open diff, because when i had my 325, if i gave it too much gas only one wheel would spin and the tail wouldn't go anywhere, but now i have to be more careful
I'm the other way around. I much prefer the limited slip diff for exactly that reason. When I want the rear end of the car to step out so I can point the car using the throttle, there's nothing more frustrating than having only one rear wheel break traction with the other wheel refusing to let go.

Primarily the LSD gives you a traction advantage if you have one rear wheel on ice and the other on dry pavement, where an open diff will just spin the wheel on the ice with no useful torque going to the wheel with grip on the pavement. But the secondary benefit of an LSD is the confidence of knowing it will consistently handle the same way every time, spinning both wheels on demand, whereas you never know with an open diff if it will spin only one wheel or the other or both together.
January 12, 2009 10:07AM
Quote
Ferdinand
Primarily the LSD gives you a traction advantage if you have one rear wheel on ice and the other on dry pavement, where an open diff will just spin the wheel on the ice with no useful torque going to the wheel with grip on the pavement. But the secondary benefit of an LSD is the confidence of knowing it will consistently handle the same way every time, spinning both wheels on demand, whereas you never know with an open diff if it will spin only one wheel or the other or both together.
I'm with Ferdinand on this, but I will add a third benefit: an LSD is simply more fun to drive. I like it so much I have two of them in my E30, for twice the winter fun. smiling smiley

__________
Dave
'91 325iX
January 13, 2009 03:44AM
i agree with the fun factor, that's why i drive a BMW.
but imagine this: you need to go from point A to point B, 500 km, mountain roads, lots of snow and many parts with ice under snow. and you need to get there fast and safe (let's say you have some women onboard and you don't want them to yell, but they want to get to their kids very soon).

after my tests, i will get there a LOT faster with the opel or the hyundai, than with any of my bimmers sad smiley

i did some more driving with my LSD these days, i am starting to feel more confindent about it, but the car is still not nearly as stable as the FWD's in the test above. and it feels a lot more unsafe.

--
A physics truck just turned over outside. There's physics everywhere!



Edited 1 time(s). Last edit at 01/13/2009 03:45AM by jaffar.
February 22, 2009 06:48PM
Quote
jaffar
In the past days my oppinion towards BMW (at least old ones) has changed for worse, while at the same time my oppinion for cheaper cars has changed for better. Why ? Read...

Finally, it's winter, time to have lots of fun with my BMW...
Then I take my g/f's car, which is a 2008 Opel Astra 1.9 diesel...
Then I take a friend's car, which is a 2006 Hyundai Sonata, 2.4...

So, now for the conclusions: what makes a car perform SO DAMN well ?

The only thing I'll add here is that yes, weight does matter. Weight can be a killer, and I know nothing about these two cars you listed, except that the Hyundai Sonata is 400lbs heavier than a E30 325i.
I know that when I stick two grown adults in the back seat of my E30, my traction is a lot better, especially for accelerating.

In another extreme case, a friend of mine has a 1997 Suburban. No Season tires all year around, and only ever puts it in 4-wheel drive for safety for-the-fun-of-it reasons. However, the thing is a tank at almost twice the weight of the E30 at 5200 lbs, and unlike a truck, there is plenty of weight over those rear wheels. I could stud my car and it would still lose a drag race to that suburban, on snow or ice.

So, there are plenty of factors, and I can't say which is playing the largest part. But along with what everyone else is saying, don't discount weight! smiling smiley

Cheers,
~Tyler


side note: You don't want to put an unbalanced 5200lbs vehicle into a slide and expect to get out of it very easily, or quickly smiling smiley
February 22, 2009 06:54PM
Quote
jaffar
i agree with the fun factor, that's why i drive a BMW.
after my tests, i will get there a LOT faster with the opel or the hyundai, than with any of my bimmers sad smiley
...but the car is still not nearly as stable as the FWD's in the test above. and it feels a lot more unsafe.

Oh, and one more thing. Let's not confuse BMW's with "Will-perform-amazingly-in-all-conditions" vehicles.
Sure, the tires, driver, and modifiable weight can change a particular vehicle's performance a lot. But in the end, some vehicles inherently (by design or not) have characteristics that make them better in snow. My friend and I are equally good drivers, and in the summer my E30 and I toast him and his 95 Subaru Legacy. Come winter, there isn't a damn thing I can do to keep up with him :-)
February 22, 2009 07:36PM
Quote
Earendil
in the summer my E30 and I toast him and his 95 Subaru Legacy. Come winter, there isn't a damn thing I can do to keep up with him :-)
Sure there is: get an iX. winking smiley

__________
Dave
'91 325iX
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