Daily driver thread re AWD poll

[3rd party]

I would need to use the M5 as a daily driver in cold climates and hilly terrain. The difference in price btwn RWD and AWD is now $2300, less than the cost of winter tires and wheels. What would be your choice? I'm waiting on the 2nd year of the new M5 AWD, myself.

[quintics]

Originally Posted by 3rd party

I would need to use the M5 as a daily driver in cold climates and hilly terrain. The $2300 difference in price btwn RWD and AWD is now $2300, less than the cost of winter tires and wheels. What would be your choice? I'm waiting on the 2nd year of the new M5 AWD, myself.

I've been using RWD w/ the michelin PSS on ice/slush and as long as you're careful with the throttle it really isn't that bad. Albeit, in accumulated snow it's bad, but that's what I've got my Lexus for.

[stealth.pilot]

Originally Posted by 3rd party

I would need to use the M5 as a daily driver in cold climates and hilly terrain. The $2300 difference in price btwn RWD and AWD is now $2300, less than the cost of winter tires and wheels. What would be your choice? I'm waiting on the 2nd year of the new M5 AWD, myself.

There is no reason to wait until 2018. Most of us will go through 2 cars by then. There are plenty of cars to choose from to wait out the next 4 years. I would suggest the CLS63 sAMG.

The only reason to wait 4 years is if you need 4 years to get to a point where you have the budget for it.

[eleven11]

Keep in mind that driving in considerable winter weather would still need winter tires, even with AWD. Proper tires will make more of a difference than having AWD. I wouldn't even drive a Jeep with our stock tires, if the roads were covered in snow/ice. Where is the $2300 quote coming from?

I don't live in an area with major winter weather, but it's enough to need winter tires. My M5 does just fine with this setup. If I had to travel routinely in more harsh winter weather, I would personally lean toward an SUV, but would consider testing someones AWD AMG (as Stealth suggested), and Panamera 4S or GTS.

[3rd party]

Originally Posted by stealth.pilot

There is no reason to wait until 2018. Most of us will go through 2 cars by then. There are plenty of cars to choose from to wait out the next 4 years. I would suggest the CLS63 sAMG.

The only reason to wait 4 years is if you need 4 years to get to a point where you have the budget for it.

I'm waiting on one of yours. They are spectacular. Was thinking of a 550x in the meantime, till the M5 awd came out. I'd like to order one and keep it for a good number of years which is my mo. The 550 would be a glimpse of the power of the M5 for me.

[3rd party]

Originally Posted by eleven11

Keep in mind that driving in considerable winter weather would still need winter tires, even with AWD. Proper tires will make more of a difference than having AWD. I wouldn't even drive a Jeep with our stock tires, if the roads were covered in snow/ice. Where is the $2300 quote coming from?

I don't live in an area with major winter weather, but it's enough to need winter tires. My M5 does just fine with this setup. If I had to travel routinely in more harsh winter weather, I would personally lean toward an SUV, but would consider testing someones AWD AMG (as Stealth suggested), and Panamera 4S or GTS.

The $2300 is the difference btwn rwd and awd in the 5 series. No doubt the M5 would need to be substantially stronger but doubt it would a $4000 plus option.

[stealth.pilot]

Originally Posted by 3rd party

I'm waiting on one of yours. They are spectacular. Was thinking of a 550x in the meantime, till the M5 awd came out. I'd like to order one and keep it for a good number of years which is my mo. The 550 would be a glimpse of the power of the M5 for me.

Maybe look at a Dinan 550xi from 2012. Those have M5 like power levels whereas the latest one cannot be tuned.

Only catch is it is a lot of power for a car which doesn't have the handling to match.

[ezmaass]

Originally Posted by stealth.pilot

Maybe look at a Dinan 550xi from 2012. Those have M5 like power levels whereas the latest one cannot be tuned.

Only catch is it is a lot of power for a car which doesn't have the handling to match.

There's a BMS N63Tu tune for the 2014+ 550. Some of the guys have begun testing them from what I've seen. Supposedly the results are strong. I'm sure Dinan won't be far behind.

Lack of xDrive is one of the main factors that kept me from seriously considering the M5 - if BMW added it, I'm pretty sure it would have had a better chance for me.

[shahano]

Originally Posted by 3rd party

I would need to use the M5 as a daily driver in cold climates and hilly terrain. The $2300 difference in price btwn RWD and AWD is now $2300, less than the cost of winter tires and wheels. What would be your choice? I'm waiting on the 2nd year of the new M5 AWD, myself.

I am sorry but winter tires cannot be replaced. My brother had an AWD car, and when mine is on winter tires, it handles better than his with his all season tires.

Now if we both had winters, that would be a different story..

[JOHNBMWM5]

Originally Posted by quintics

I've been using RWD w/ the michelin PSS on ice/slush and as long as you're careful with the throttle it really isn't that bad. Albeit, in accumulated snow it's bad, but that's what I've got my Lexus for.

BUT Winter tyres are way Cheaper than a Lexus........

[Stash21]

RS6 in the meantime.

[stealth.pilot]

Originally Posted by shahano

I am sorry but winter tires cannot be replaced. My brother had an AWD car, and when mine is on winter tires, it handles better than his with his all season tires.

Now if we both had winters, that would be a different story..

Exactly. Unfortunately most people in North America are delusional about all wheel drive.

[ezmaass]

Originally Posted by shahano

I am sorry but winter tires cannot be replaced. My brother had an AWD car, and when mine is on winter tires, it handles better than his with his all season tires.

Now if we both had winters, that would be a different story..

I disagree. I've lived in the northeast pretty much my entire life - at times, places like Syracuse, NY - where I've had RWD BMWs running on A/S tires. Never a mishap. Adding winter tires would help, undoubtedly. And adding xDrive beyond that would help even more. But they're certainly not requirements for every car.

Here in CT we've been slammed several times with snow storms this winter. My 550xi has A/S tires on it. No issues... not even the smallest inkling that the car ever needed more traction and couldn't find it. I've driven it through 6 inches of snow uphill... again, no issues. My RWD BMWs wouldn't have made it, potentially not even with snow tires.

As for your comparison, not all AWD cars are created equal, either. My wife's Audi Q5 is sometimes scarier to drive in snow than my former RWD 335. And the Q5 is certainly not as "grippy" in comparison to the 550xi. Part of that may be that it's 400lbs lighter than the 550. But the Q5 certainly spins tires in circumstances where the BMW doesn't. So, we really need to be comparing the same car with and without AWD.

When you have 560hp going to two rear wheels, I'd say winter tires are a must if you're going out in any amount of snow. But if I needed to go out in the snow here, and I was given a choice between an M5 with winter tires and a 550xi with A/S... it would be a no brainer... I'd be taking the 550xi.

[stealth.pilot]

Originally Posted by ezmaass

I disagree. I've lived in the northeast pretty much my entire life - at times, places like Syracuse, NY - where I've had RWD BMWs running on A/S tires. Never a mishap. Adding winter tires would help, undoubtedly. And adding xDrive beyond that would help even more. But they're certainly not requirements for every car.

Here in CT we've been slammed several times with snow storms this winter. My 550xi has A/S tires on it. No issues... not even the smallest inkling that the car ever needed more traction and couldn't find it. I've driven it through 6 inches of snow uphill... again, no issues. My RWD BMWs wouldn't have made it, potentially not even with snow tires. Speculation?

As for your comparison, not all AWD cars are created equal, either. My wife's Audi Q5 is sometimes scarier to drive in snow than my former RWD 335. And the Q5 is certainly not as "grippy" in comparison to the 550xi. Part of that may be that it's 400lbs lighter than the 550. But the Q5 certainly spins tires in circumstances where the BMW doesn't. So, we really need to be comparing the same car with and without AWD.

When you have 560hp going to two rear wheels, I'd say winter tires are a must if you're going out in any amount of snow. But if I needed to go out in the snow here, and I was given a choice between an M5 with winter tires and a 550xi with A/S... it would be a no brainer... I'd be taking the 550xi.

Correct me if I'm wrong, but nowhere in your post did you mention having owned snow tires. You said you had RWD BMWs with A/S tires, AWD Audi with A/S tires, and AWD BMW with A/S tires.

So your conclusion is not based on any actual experience with snow tires whereas Shahano's post was based on actual experience with both types of tires.

[PatrickC23]

Im not all that familiar with All-wheel, but Id opt for it if the M5 came with it, just to be safe along with snow tires.

Im assuming the all wheel drive system adds substantial weight to the car(?).

[DrewM5]

Originally Posted by ezmaass

I disagree. I've lived in the northeast pretty much my entire life - at times, places like Syracuse, NY - where I've had RWD BMWs running on A/S tires. Never a mishap. Adding winter tires would help, undoubtedly. And adding xDrive beyond that would help even more. But they're certainly not requirements for every car.

Here in CT we've been slammed several times with snow storms this winter. My 550xi has A/S tires on it. No issues... not even the smallest inkling that the car ever needed more traction and couldn't find it. I've driven it through 6 inches of snow uphill... again, no issues. My RWD BMWs wouldn't have made it, potentially not even with snow tires.

As for your comparison, not all AWD cars are created equal, either. My wife's Audi Q5 is sometimes scarier to drive in snow than my former RWD 335. And the Q5 is certainly not as "grippy" in comparison to the 550xi. Part of that may be that it's 400lbs lighter than the 550. But the Q5 certainly spins tires in circumstances where the BMW doesn't. So, we really need to be comparing the same car with and without AWD.

When you have 560hp going to two rear wheels, I'd say winter tires are a must if you're going out in any amount of snow. But if I needed to go out in the snow here, and I was given a choice between an M5 with winter tires and a 550xi with A/S... it would be a no brainer... I'd be taking the 550xi.

Buut you are comparinf A/S tires. The Michelins are a dedicated high performance summer tire with a very different compound and a very different reaction to the cold. Even shod on a AWD car, they would be useless in the very cold or snowy conditions.

[JOHNBMWM5]

Originally Posted by ezmaass

I disagree. I've lived in the northeast pretty much my entire life - at times, places like Syracuse, NY - where I've had RWD BMWs running on A/S tires. Never a mishap. Adding winter tires would help, undoubtedly. And adding xDrive beyond that would help even more. But they're certainly not requirements for every car.

Here in CT we've been slammed several times with snow storms this winter. My 550xi has A/S tires on it. No issues... not even the smallest inkling that the car ever needed more traction and couldn't find it. I've driven it through 6 inches of snow uphill... again, no issues. My RWD BMWs wouldn't have made it, potentially not even with snow tires.

As for your comparison, not all AWD cars are created equal, either. My wife's Audi Q5 is sometimes scarier to drive in snow than my former RWD 335. And the Q5 is certainly not as "grippy" in comparison to the 550xi. Part of that may be that it's 400lbs lighter than the 550. But the Q5 certainly spins tires in circumstances where the BMW doesn't. So, we really need to be comparing the same car with and without AWD.

When you have 560hp going to two rear wheels, I'd say winter tires are a must if you're going out in any amount of snow. But if I needed to go out in the snow here, and I was given a choice between an M5 with winter tires and a 550xi with A/S... it would be a no brainer... I'd be taking the 550xi.

Try Michelin Alpin PA4 in 20" then come back with your thoughts. All seasons not much good in snow IMO on M5's.

[3rd party]

Originally Posted by PatrickC23

Im not all that familiar with All-wheel, but Id opt for it if the M5 came with it, just to be safe along with snow tires.

Im assuming the all wheel drive system adds substantial weight to the car(?).

The awd drive version of the 550 is a 154lbs heavier than the RWD.

[3rd party]

I had a 1991 3 series w snow tires and that thing was unstoppable, even the winter of 94 when in snowed about 17 times in the NY metropolitan area. The 50/50 weight distribution is key to mobility. I have a large amount of experience w driving 4x4's, snow cats, and living in ski towns and working in the mountains of the western US which got a considerable amount of snow so that helped enormously in my being able to get around.

Today on my father's street there was 6" of wet, greasy snow. The worst kind to drive in and nearly impossible to move if you're not on virtually flat, level surface. My awd drive was essential in getting off the street to a plowed road.

The one thing the M5 has that an ordinary rwd doesn't is the limited slip differential which makes a huge difference. RWD cars not equipped w LSD are horrible in snow even w snow tires. The difference makes it hard to draw comparisons btwn cars regarding ability in snow.

[ezmaass]

Originally Posted by stealth.pilot

Correct me if I'm wrong, but nowhere in your post did you mention having owned snow tires. You said you had RWD BMWs with A/S tires, AWD Audi with A/S tires, and AWD BMW with A/S tires.

So your conclusion is not based on any actual experience with snow tires whereas Shahano's post was based on actual experience with both types of tires.

Yes, I should have mentioned that I have indeed owned snow tires - much earlier-on with my RWD BMWs, until I decided they were unnecessary that is.

Traction is the result of friction between the tire and the ground. The resulting coefficient of friction between the two directly determines available traction. That coefficient of friction is also impacted by the downward force on it (weight of the car over each tire) - the more weight, the more friction. And yes, the compound of the tire itself, along with the surface its driving on - dry, wet, snowy, icy, etc.

The car's locomotive force is determined by torque force on the driving wheels; however, if the torque forces overcome friction, the wheels spin. In a RWD car, all available torque is spread across two driving wheels. Those two driving wheels also only have half of the car's total weight applied to them, which as noted above is a key part of the wheel's coefficient of friction. Assuming you're spreading the torque of the engine evenly across all four wheels in an AWD car, each with a proportional distribution of the car's weight sitting on top, your longitudinal (locomotive) force is going to benefit from 4x, versus 2x, available "traction" where your rubber meets the road. In a RWD scenario where the car is attempting to start from a stop, the two front wheels, along with their potential traction, just goes to waste - there are no longitudinal forces applied to these wheels. The rear wheels will still have the same coefficient of friction as they do in an AWD car, and they'll still be overcome (slip) at the same threshold of torque.

So does a RWD car with snow tires get more traction than an AWD car with A/S tires? No. You're not likely to DOUBLE the coefficient of friction ("u") simply by using a winter tire over an A/S tire - results I've seen are roughly 20 - 30% increases. If the average A/S tire received a coefficient of 0.7 on dry surfaces and a low-end of 0.4 on wet/snowy surfaces (taken from research of Jones and Childer "Contemporary College Physics"), your winter tires would need to DOUBLE the available "u" value on a RWD car to "make up for" the lack of available locomotive forces on the 2 front wheels. Good luck with that as a racing slick provides a relative u value of 0.9 on dry surfaces to put things in perspective. And that's just talking about longitudinal forces. Once you add in lateral forces (car needs to steer/turn), the picture grows even more grim for a RWD car compared to AWD.

Fact is, even without getting into the physics of it, common sense should tell you that AWD cars wouldn't even exist on the market if their performance could simply be matched by putting "better tires" on two driving wheels. It just isn't possible. Winter tires will increase the coefficient of friction in snowy/icy conditions over A/S tires, but they will NOT provide for 2x the performance of an A/S tire, as that would require 2x the u value - said another way, locomotive forces of 4 driving A/S tires is greater than locomotive forces of 2 driving winter tires if all else is equal (car, weight distribution, road surface, etc).

So, just to be clear - I would never recommend using a summer tire on ANY car to drive in the snow. They're just not suited and provide little traction once the temperature drops below freezing. But, as I've said above, winter tires are certainly not necessary... and if given the choice between the same car with AWD and A/S tires versus a RWD version with snow tires, I'd take the AWD car. The maximum performance will obviously be obtained by putting winter tires on an AWD car... making the choices, from worst to best:

1. RWD car w/ A/S tires
2. RWD car w/ winter tires
3. AWD car w/ A/S tires
4. AWD car w/ winter tires

All of the above is based upon simple physics - where forces are applied evenly. A system like xDrive, where forces can be dynamically shifted up to 100%, will even further emphasize its advantage over RWD, even with a limited slip differential. Now you have a system that can pick and chose among 4 wheels, monitoring their specific thresholds of traction, and shift torque to exactly where it can be used. In a RWD car with the back wheels sitting on a patch of ice, no amount of spectacular winter tire performance is going to save it.

[stealth.pilot]

ezmaas I agree its best to compare with the same car.

[stealth.pilot]