[flipmde786]

Originally Posted by ward

if any power at all goes to the fronts you're loosing cornering grip (in exchange for forward force)

if the system worked as planned then it would be OK, but any power to the front wheels at all encourages plow/understeer/badness

The point was that it is RWD biased until you need otherwise. Saying that power can go up to 100% front was for the purpose of winter traction.

[flipmde786]

Originally Posted by jmatero

I don't understand why there should be any real difference in dry weather handling between Xdrive and RWD..... Here's the text straight from BMW regarding Xdrive on the E90 for 2006:

"Ask any driving enthusiast: for balanced handling and sports-car-like agility, you want rear-wheel drive. But what if, 20% of the time, you need an all-wheel drive vehicle that can tackle steep slippery hills? Must you sacrifice the thrilling, responsive handling of rear-wheel drive the rest of the time? Not if you have XDrive All-wheel drive. On roads with good traction, xDrive sends 100% of the power to the rear wheels for legendary BMW handling. The instant xDrive detects wheel spin, it smoothly redistributes up to 100% of available power to the front wheels. So when you need it, you enjoy surefooted grip on steep, slippery roads - and pure driving fun all year 'round."

Where did you find that quote? I have a question about the authenticity of that statement. BMW said xDrive maintains a 40/60 front/rear split in normal conditions, which was discussed in another thread.

Edit: By the way, I know that xDrive is infinitely variable. However, it varies only when necessary from 40/60.

[jmatero]

It comes directly from BMW's "BMW: Beyond expectations" brochure. The beauty of xdrive is that it's essentially a RWD vehicle... the front wheels are dead.... unless rear wheel slip is detected. That's why if you were to debadge a 325i and 325xi and drive both on dry pavement, you would not be able to tell which you were driving. I drove both back to back and I couldn't tell the difference... and I'm coming from a Mazdaspeed Miata... an well-balanced RWD vehicle. I took the same curves in both bmw's.. at high-speed.. that I drive every day to work and there was no difference. I'd be shocked to learn it was 60/40. That sounds more like an Audi. Or maybe pre-2006 xdrive?

[ward]

Originally Posted by jmatero

It comes directly from BMW's "BMW: Beyond expectations" brochure. The beauty of xdrive is that it's essentially a RWD vehicle... the front wheels are dead.... unless rear wheel slip is detected. That's why if you were to debadge a 325i and 325xi and drive both on dry pavement, you would not be able to tell which you were driving. I drove both back to back and I couldn't tell the difference... and I'm coming from a Mazdaspeed Miata... an well-balanced RWD vehicle. I took the same curves in both bmw's.. at high-speed.. that I drive every day to work and there was no difference. I'd be shocked to learn it was 60/40. That sounds more like an Audi. Or maybe pre-2006 xdrive?

if you can't tell the difference................


that tells more about your driving skill than the AWD system

[flipmde786]

Originally Posted by jmatero

It comes directly from BMW's "BMW: Beyond expectations" brochure. The beauty of xdrive is that it's essentially a RWD vehicle... the front wheels are dead.... unless rear wheel slip is detected. That's why if you were to debadge a 325i and 325xi and drive both on dry pavement, you would not be able to tell which you were driving. I drove both back to back and I couldn't tell the difference... and I'm coming from a Mazdaspeed Miata... an well-balanced RWD vehicle. I took the same curves in both bmw's.. at high-speed.. that I drive every day to work and there was no difference. I'd be shocked to learn it was 60/40. That sounds more like an Audi. Or maybe pre-2006 xdrive?

That's interesting because I learned that there is a 40/60 split in normal conditions from the Beyond Expectations feature on the BMW website.

Here's a link to the thread in which we discussed this:
http://www.e90post.com/forums/showthread.php?t=8192

[lhoboy8]

From the International website

"In the BMW 325xi, 330xi and 330xd, the xDrive all-wheel drive system provides more traction, directional stability and safety. On dry roads, xDrive distributes 40% of the power to the front wheels and 60% to the rear, combining the advantages of four-wheel drive with the agility of a BMW 3 Series. If the system senses the possibility of the car spinning when driving on wintry roads, it redistributes power between the axles within milliseconds, preventing under- or oversteer before it starts."

I was hoping jmatero was right, since I've heard both. But I think this pretty much confirms it. It's directly copy and pasted from the international website since I couldn't find anything specific on bmwusa. I drove the both the 330i, and I own a 330xi. I can only tell a difference when I make sharp corners, Otherwise the awd's difference in "feel" seems negligible. Plus I drove an e46 rwd for 4 years - yet I think the e90xi still handles better. But I'm sure the e90i's are even better yet. Too bad the weather around here is horrible. Can't wait to get the hell outta boston.

[jmatero]

So What's right... the website or the product literature? They contradict eachother.

[Tony]

Not sure why there's a gap, but the big gap in the wheel well is ugly. Big time Turn-Off. It makes the car look like its riding on stilts. The huge wheel well gap is definitely not aesthetically pleasing. I didn’t get an XI for that exact reason. What I don’t understand is that Audi actually lowers the ride hide with Quattro equipped sports package. Why can’t BMW do the same? My guess is that there’s a mechanical reason, not the crap that BMW is trying to spew. If BMW’s reason is legit, then I guess that BMW doesn’t really care about aesthetics anymore. Judging from some of their latest offerings aesthetics seems to be low on BMW’s priority list.

[jmatero]

I thought the ride height was only 2/10 of an inch higher... that's damn difficult to spot.. I think the issue is more the 16" wheels not filling the wells like the 17's. The ride height on this car (a 325i) looks no different than the 325xi a few posts back.

http://www.bimmerfest.com/forums/att...id=49440&stc=1

There is no way anyone can see the ride height difference.

[lhoboy8]

compared to the standard i, it really is difficult to spot. But the wheel gap on the standard i without sports package is pretty ugly as well. The problem is that it's difficult and costlier to lower an xi since they don't make many kits for the xi. at least that's the problem as I see it.

[BKsBimmer]

The demand for AWD is booming because there is REAL difference between RWD traction and AWD traction on slippery road surfaces. Many of the posts here seem to totally ignore the fact that these conditions do not only occur in areas prone to snow and hilly terrain. Anywhere there's rain, mud, or leaves on the road (which is pretty much everywhere ) you can experience these conditions, thus justifying the demand for AWD. It's a smart choice for a lot of people. Thankfully BMW gives true driving enthusiast like me an option in the 325xi and the 330xi. I'll ride a quarter inch higher, give up .03 seconds from 0 - 60, and yes, I'll spend a little extra cash to know I have a sure footed performer on all kinds of road surfaces and driving conditions. X-Drive rules!

[Oz]

I drove a 2005 325xi as a loaner last year when I put the X5 into service. I loved the car and it was that car that interested me on a 3 series. The handling was great and it was very fast compared to my older cars.

I currently have a 330i without ZSP and I truly love my car. I honestly don't think the gap makes that much of a big deal knowing the fact that I am driving a premium vehicle. And I don't think the gap should be a major factor when buying a vehicle because everybody has different tastes. I like the 18 inch tires and the dropped cars but It doesn't suit everybody

[xdrive]

Originally Posted by BKsBimmer

The demand for AWD is booming because there is REAL difference between RWD traction and AWD traction on slippery road surfaces. Many of the posts here seem to totally ignore the fact that these conditions do not only occur in areas prone to snow and hilly terrain. Anywhere there's rain, mud, or leaves on the road (which is pretty much everywhere ) you can experience these conditions, thus justifying the demand for AWD. It's a smart choice for a lot of people. Thankfully BMW gives true driving enthusiast like me an option in the 325xi and the 330xi. I'll ride a quarter inch higher, give up .03 seconds from 0 - 60, and yes, I'll spend a little extra cash to know I have a sure footed performer on all kinds of road surfaces and driving conditions. X-Drive rules!

NICELY said! I completely agree with you. Unlike most people, I do not drive on dry pavement all year round or on the race track. To me, the 3 series is more of a everyday car... To people that only care about performance, get a REAL performance car like the M. EVEN a freakin' stock WRX STi can out perform the 330i/xi in the quarter mile or from 0-60. Sorry to burst your bubble, but the 330i/xi isn't a super fast car.. AND yes, I own a E90 330xi.

[visor]

Originally Posted by BKsBimmer

The demand for AWD is booming because there is REAL difference between RWD traction and AWD traction on slippery road surfaces. Many of the posts here seem to totally ignore the fact that these conditions do not only occur in areas prone to snow and hilly terrain. Anywhere there's rain, mud, or leaves on the road (which is pretty much everywhere ) you can experience these conditions, thus justifying the demand for AWD. It's a smart choice for a lot of people. Thankfully BMW gives true driving enthusiast like me an option in the 325xi and the 330xi. I'll ride a quarter inch higher, give up .03 seconds from 0 - 60, and yes, I'll spend a little extra cash to know I have a sure footed performer on all kinds of road surfaces and driving conditions. X-Drive rules!

Welcome to E90post!

Good points re traction in slippery conditions when going forward, but also realize that when it comes time to slow down or stop, neither X-drive nor AWD provide any advantage over RWD. If anything, the extra weight of X-drive/AWD worsens the stopping ability in slippery conditions.

So, a person driving X-drive/AWD may feel safer driving in slippery conditions because he can go faster without losing traction, but watch out when it comes time to stop!

[lux.sh]

Originally Posted by visor

So, a person driving X-drive/AWD may feel safer driving in slippery conditions because he can go faster without losing traction, but watch out when it comes time to stop!

Difference should be minimal. Perhaps, stopping distance can always be decreased by "upgrading" and "tuning", but the fact that drivetrain is different can't really be "retrofitted".

Traction is superior in AWD than RWD given most of the road conditions. This however, doesn't always translates into "better cornering". Full grip doesn't necessary provide best track time.

I would say both systems have its pros and cons. Honestly though, me being a fancy son of a gun, I prefer lower ride height look than extra traction. how sad.