Xdrive driving dynamics
Discussion
BMW are renown for their cars driving dynamics, steering, handling etc. Presumably this was based on them being rwd. This got me thinking.
How does the xdrive models drive in comparison to rwd or does that not matter anymore. Can BMW still make the claim of being the ultimate driving machine?
For owners of xdrive vehicles, at what speed do you think the all wheel traction is of benefit?
Having driven rwd cars for most of my life, I do not recall having traction issues especially in wet conditions, unless I boot the car from the lights. Maybe I drive too slowly.
I get the impression that unless you are driving at breakneck speeds round corners in wet conditions the traction is of little benefit. Oh and a quick check on a Met office website states that the average rain fall in London (where I live) is 29% per year.
How does the xdrive models drive in comparison to rwd or does that not matter anymore. Can BMW still make the claim of being the ultimate driving machine?
For owners of xdrive vehicles, at what speed do you think the all wheel traction is of benefit?
Having driven rwd cars for most of my life, I do not recall having traction issues especially in wet conditions, unless I boot the car from the lights. Maybe I drive too slowly.
I get the impression that unless you are driving at breakneck speeds round corners in wet conditions the traction is of little benefit. Oh and a quick check on a Met office website states that the average rain fall in London (where I live) is 29% per year.
I am perhaps the wrong sort of owner for a BMW as I have no time for Clarkson-type tail-out cornering, but the reasons I have one include the 40%:60% front:rear torque split of the "xdrive" system. That ratio was also the result of work by Ferguson Research many years ago, and the cars so equipped that I have driven (Sierra 4x4 and Jaguar X-Type) suited me.
The BMW handling is similar and I would describe it as rear-drive with better turn-in.
The cars these days are too clever for their own good, so in difficult conditions the computer will mess about with the balance, possibly beneficially.
No way of finding out as the ability of BMW dealers to answer relevant questions seems hampered by their (and BMW's) inability to distinguish between technical points and advertising puff. As an example, the patronising "welcome" letter referred to the benfits of a 50:50 weight distribution and the "Hofmeister kink" in the same sentence! I may be retired, but the Chartered Engineer I used to be resents that treatment, which is why I bang on about it!
The BMW handling is similar and I would describe it as rear-drive with better turn-in.
The cars these days are too clever for their own good, so in difficult conditions the computer will mess about with the balance, possibly beneficially.
No way of finding out as the ability of BMW dealers to answer relevant questions seems hampered by their (and BMW's) inability to distinguish between technical points and advertising puff. As an example, the patronising "welcome" letter referred to the benfits of a 50:50 weight distribution and the "Hofmeister kink" in the same sentence! I may be retired, but the Chartered Engineer I used to be resents that treatment, which is why I bang on about it!
Allan L said:
I am perhaps the wrong sort of owner for a BMW as I have no time for Clarkson-type tail-out cornering, but the reasons I have one include the 40%:60% front:rear torque split of the "xdrive" system. That ratio was also the result of work by Ferguson Research many years ago, and the cars so equipped that I have driven (Sierra 4x4 and Jaguar X-Type) suited me.
The BMW handling is similar and I would describe it as rear-drive with better turn-in.
The cars these days are too clever for their own good, so in difficult conditions the computer will mess about with the balance, possibly beneficially.
No way of finding out as the ability of BMW dealers to answer relevant questions seems hampered by their (and BMW's) inability to distinguish between technical points and advertising puff. As an example, the patronising "welcome" letter referred to the benfits of a 50:50 weight distribution and the "Hofmeister kink" in the same sentence! I may be retired, but the Chartered Engineer I used to be resents that treatment, which is why I bang on about it!
Does that mean in normal driving conditions the split is 40% front and 60% rear or is it 100% rear and up to 40/60 when traction is limited?The BMW handling is similar and I would describe it as rear-drive with better turn-in.
The cars these days are too clever for their own good, so in difficult conditions the computer will mess about with the balance, possibly beneficially.
No way of finding out as the ability of BMW dealers to answer relevant questions seems hampered by their (and BMW's) inability to distinguish between technical points and advertising puff. As an example, the patronising "welcome" letter referred to the benfits of a 50:50 weight distribution and the "Hofmeister kink" in the same sentence! I may be retired, but the Chartered Engineer I used to be resents that treatment, which is why I bang on about it!
Selmer Mk6 said:
Does that mean in normal driving conditions the split is 40% front and 60% rear or is it 100% rear and up to 40/60 when traction is limited?
I understand it is a normal mechanical 40:60 before the computer interferes with it. It certainly feels like that - as I said, rear drive with better turn-in.The VAG system is 100% front drive until the computer thinks you need some rear, presumably because it detects slip - but in my book that's trying to recover from a situation one shouldn't be in.
I had a string of large-engined AWD cars, the last being a 330d Touring xDrive - the main characteristic I'd say, is 'neutral' handling i.e. neither oversteer or understeer. You can still induce a 4-wheel drift if you get the power wrong in the wet (I did it on a roundabout) but you have to press way too hard to get it do this. Some people don't like this, which is fine, but I only drive on public roads so for me, inducing over/understeer is a mistake on my part - I shouldn't be doing it. xDrive does affect the front steering to a degree, as you might expect. My current M235i is far more nimble (of course, compared to an F31!) part of which is the 'freer' front (sans driveshafts) but part other factors too. I also found that the xDrive was never intrusive: you were never aware of it engaging more/less power to the front.
I'd say that xDrive is great if you have a big engine, want very stable and predictable handling, good wet road handling, and overall quite a 'boring' but very safe ride. And of course, if you are likely to hit snow, it's excellent (but you need winter tyres on as well).
I swapped to a smaller convertible because I wasn't doing the long motorway trips and cross-country drives to customers any more and so we could go for something a bit more fun. If the M235i had been available with xDrive in the UK in the same way as it is in RHD abroad, I would have seriously considered having it. But it would have been a very close decision: A bit more agility on the RWD version versus somewhat less agility but more stability on the xDrive.
I'd say that xDrive is great if you have a big engine, want very stable and predictable handling, good wet road handling, and overall quite a 'boring' but very safe ride. And of course, if you are likely to hit snow, it's excellent (but you need winter tyres on as well).
I swapped to a smaller convertible because I wasn't doing the long motorway trips and cross-country drives to customers any more and so we could go for something a bit more fun. If the M235i had been available with xDrive in the UK in the same way as it is in RHD abroad, I would have seriously considered having it. But it would have been a very close decision: A bit more agility on the RWD version versus somewhat less agility but more stability on the xDrive.
Edited by msej449 on Sunday 1st January 17:53
My opinion on xdrive is that it improves traction tremendously but at the expensive of handling, I found the turn in to be awful, the steering numb and the push me pull me shenanigans of the xdrive system unpleasant.
For me Sdrive versions are far more balanced and pleasurable to drive.
For me Sdrive versions are far more balanced and pleasurable to drive.
IMHO, xDrive should be suited to the larger SUV's as they are the ones that do actually need the AWD system in order for them to handle as well as they should (and beat the competitors in the segment as well). It is a great system which makes the car handle very equally around corners. The combination of M-sport suspension and xDrive makes for a very flat car when going around corners, which allows for the car to handle very well even though it's CoG is much higher than normal.
The idea of xDrive is that its continuously variable at all times. When driving, the car sets the front/back drive ratio to be 40:60. When the ABS/DSC sense any slip at the front or back axle, then the car sends up to 100% power to the front/back of the car. In a way, the xDrive can act as a safety system to prevent skids. As for driving dynamics, as other people mentioned, there is the usual 'push' out of corners due to the slightly extra amount of power in the back, but the understeer is countered by the fact that the front wheels are being driven to, adding more handling control.
What makes xDrive better than the other competitors (quattro, 4matic) is that all wheels are always being driven. What makes 4matic not as good is that there are only three modes to their AWD system, which applies only certain torque splits between the front and back, they can't actually vary the torque split on the go. This also controls grip by braking wheels, not driving power to certain wheels, and this can cause for understeer. In contrast, this also means that 4matic can be a bit better off roading than xDrive systems, but who off-roads a BMW???
Also, what makes quattro not as good is that, due to some cars having longitudinally mounted engines and some having transverse engines, there had to be different versions of quattro. Thus, cars with longitudinal engines such as the Q7, RS4 etc had better driving dynamics. Even still, quattro can't distribute 100% of power to the front or back. The transverse systems were not permanent 4WD anyway, so there is the big disadvantage there as the rear diff wouldn't be activated.
In a way, the xDrive system is the only system that any automaker makes that doesn't interfere with driving dynamics of the car. xDrive was made to allow BMW to still say 'ultimate driving machine' about all their cars, including ones with xDrive (except the 2 series, horrid car).
The idea of xDrive is that its continuously variable at all times. When driving, the car sets the front/back drive ratio to be 40:60. When the ABS/DSC sense any slip at the front or back axle, then the car sends up to 100% power to the front/back of the car. In a way, the xDrive can act as a safety system to prevent skids. As for driving dynamics, as other people mentioned, there is the usual 'push' out of corners due to the slightly extra amount of power in the back, but the understeer is countered by the fact that the front wheels are being driven to, adding more handling control.
What makes xDrive better than the other competitors (quattro, 4matic) is that all wheels are always being driven. What makes 4matic not as good is that there are only three modes to their AWD system, which applies only certain torque splits between the front and back, they can't actually vary the torque split on the go. This also controls grip by braking wheels, not driving power to certain wheels, and this can cause for understeer. In contrast, this also means that 4matic can be a bit better off roading than xDrive systems, but who off-roads a BMW???
Also, what makes quattro not as good is that, due to some cars having longitudinally mounted engines and some having transverse engines, there had to be different versions of quattro. Thus, cars with longitudinal engines such as the Q7, RS4 etc had better driving dynamics. Even still, quattro can't distribute 100% of power to the front or back. The transverse systems were not permanent 4WD anyway, so there is the big disadvantage there as the rear diff wouldn't be activated.
In a way, the xDrive system is the only system that any automaker makes that doesn't interfere with driving dynamics of the car. xDrive was made to allow BMW to still say 'ultimate driving machine' about all their cars, including ones with xDrive (except the 2 series, horrid car).
Wills2 said:
My opinion on xdrive is that it improves traction tremendously but at the expensive of handling, I found the turn in to be awful, the steering numb and the push me pull me shenanigans of the xdrive system unpleasant.
For me Sdrive versions are far more balanced and pleasurable to drive.
It is very easy to confuse the effect of the SE springs with xDrive, since BMW only sell them as a package on the F3x, and I think that's what you have done here. For me Sdrive versions are far more balanced and pleasurable to drive.
I agree with you that the 335d xDrive from the factory has poor turn-in and the handling is not what you would expect from a BMW. However, you really need to try it with ACS springs and then compare that with an sDrive 330d to realise just how much of the problem comes from the factory suspension arrangement. The turn-in is significantly better on the xDrive 335d with ACS, than the standard sDrive 330d M Sport. In addition to the improved traction, it is a much more composed car.
In moving from the E9x to the F3x, BMW prioritised comfort over handling, so even the sDrive M Sport cars don't handle anything like as well as their predecessors. All of them benefit from at least upgrading the springs, and this can be done with very little impact on ride comfort which just goes to show how wrong BMW have got it. It is annoying to have to modify a BMW to get car which handles, but the result of that one small change is impressive.
Having driven most BMWs, and owned quite a few sDrive models, I think xDrive is a really good system.
335d said:
Wills2 said:
My opinion on xdrive is that it improves traction tremendously but at the expensive of handling, I found the turn in to be awful, the steering numb and the push me pull me shenanigans of the xdrive system unpleasant.
For me Sdrive versions are far more balanced and pleasurable to drive.
It is very easy to confuse the effect of the SE springs with xDrive, since BMW only sell them as a package on the F3x, and I think that's what you have done here. For me Sdrive versions are far more balanced and pleasurable to drive.
I agree with you that the 335d xDrive from the factory has poor turn-in and the handling is not what you would expect from a BMW. However, you really need to try it with ACS springs and then compare that with an sDrive 330d to realise just how much of the problem comes from the factory suspension arrangement. The turn-in is significantly better on the xDrive 335d with ACS, than the standard sDrive 330d M Sport. In addition to the improved traction, it is a much more composed car.
In moving from the E9x to the F3x, BMW prioritised comfort over handling, so even the sDrive M Sport cars don't handle anything like as well as their predecessors. All of them benefit from at least upgrading the springs, and this can be done with very little impact on ride comfort which just goes to show how wrong BMW have got it. It is annoying to have to modify a BMW to get car which handles, but the result of that one small change is impressive.
Having driven most BMWs, and owned quite a few sDrive models, I think xDrive is a really good system.
Our xdrive e61 530d is obviously a generation older than the "F" models, but I'm finding it quite a benefit. A big old barge like a 5er estate is never really going to be the pinnacle of handling prowess in any event, so I'm happy to trade a bit of "dynamics" for better winter weather capabilities. But it does feel heavier and less direct than the old 523i we had back in the UK.
That said, I drove home very late last night (with enthusiasm) over the hills and, for such a heavy old hector, it acquitted itself admirably.
I'd be interested to compare mpgs with anyone who happens to have a rwd e60/1 530d. Over the last two weeks / 3,000 km it has managed about 34mpg, which perhaps isn't quite as good as I'd hoped. So I'd be keen to know how heavily the xdrive gubbins impacts economy.
That said, I drove home very late last night (with enthusiasm) over the hills and, for such a heavy old hector, it acquitted itself admirably.
I'd be interested to compare mpgs with anyone who happens to have a rwd e60/1 530d. Over the last two weeks / 3,000 km it has managed about 34mpg, which perhaps isn't quite as good as I'd hoped. So I'd be keen to know how heavily the xdrive gubbins impacts economy.
CarsOrBikes said:
"The combination of M-sport suspension and xDrive makes for a very flat car when going around corners"
Except you can't have both can you? Adaptive, but not M Sport with xDrive
Our E70 X5 has M-sport with xDrive and bags on the back due to third row seating. No adaptive drive yet it still handles flat. Except you can't have both can you? Adaptive, but not M Sport with xDrive
Wills2 said:
My opinion on xdrive is that it improves traction tremendously but at the expensive of handling, I found the turn in to be awful, the steering numb and the push me pull me shenanigans of the xdrive system unpleasant.
For me Sdrive versions are far more balanced and pleasurable to drive.
And yet BMW will now only be offering certain models of the new 5 Series in XDrive form - including the 540i For me Sdrive versions are far more balanced and pleasurable to drive.
Timbuktu said:
They'd better not start forcing x-drive on the M cars - although I think (hope) it's unlikely?
I think it's pretty likely that the G30 M5 will be xDrive only. Perhaps the smaller M models are 'safe' for now. I don't see this move towards xDrive as such a bad thing. BMW are very good at setting it up with a RWD bias. With the right tyres and suspension (MPSS and ACS springs in my case) even a 335d feels like it's RWD most of the time, and clearly the M division can set up a car a lot better than that.
Fox- said:
Wills2 said:
My opinion on xdrive is that it improves traction tremendously but at the expensive of handling, I found the turn in to be awful, the steering numb and the push me pull me shenanigans of the xdrive system unpleasant.
For me Sdrive versions are far more balanced and pleasurable to drive.
And yet BMW will now only be offering certain models of the new 5 Series in XDrive form - including the 540i For me Sdrive versions are far more balanced and pleasurable to drive.
One thing I do not really understand, having read much recently about the 335d suspension, is why the SE suspension on my X5 M sport feels so good. What is the explanation for the SE suspension on that model being excellent when the newer 335d seems to be suffering so much from the factory? What went wrong?
EDIT: As Rayvan says above, the X5 handles very flatly. It feels well sorted for a car never mind a big one. And this compared to my e46 330d sport. You would have thought at the very least BMW could have made a 335d that handled as well as an X5. Seemingly not?
EDIT: As Rayvan says above, the X5 handles very flatly. It feels well sorted for a car never mind a big one. And this compared to my e46 330d sport. You would have thought at the very least BMW could have made a 335d that handled as well as an X5. Seemingly not?
Edited by jboy72 on Tuesday 3rd January 14:37
jboy72 said:
One thing I do not really understand, having read much recently about the 335d suspension, is why the SE suspension on my X5 M sport feels so good. What is the explanation for the SE suspension on that model being excellent when the newer 335d seems to be suffering so much from the factory? What went wrong?
I would imagine the owner expectations of handling on a 335d M Sport differ from that of an X5. It's likely that the 335d xDrive does handle as well as an X5 but that the complaint is that a sporting saloon should handle rather better than an SUV.Gassing Station | BMW General | Top of Page | What's New | My Stuff