330d Rwd vs 335d x drive

Dandanbmw · 09-28-2015, 08:36 PM

At Santa pod this weekend I went up against a 335d & 435d and I was very impressed with how they got off the line.
My Rwd done well considering but after 60mph my car kept the gap or maybe very slightly gained on them.
Could this be down to mine being lighter and rwd as they have 50 odd bhp extra & a little bit more torque? I would had thought they would keep pulling away from me?

casualDIYer · 09-30-2015, 09:22 AM

Yep, it's the weight and a few other things. Off the line AWD will give that little extra pull from the front wheels but as the vehicle moves faster and faster it goes from passing through a soft breeze to driving the wrong way in a hurricane. The engine needs not only to overcome wind resistance (identical regardless of drive train) but the extra weight as well. Then there is parasitic drive train loss due to the transfer case and front diff. Then you've got traction control on 4 wheels rather than 2 plus whatever farting around the computer imposes managing AWD.

None of these things (weight, drive train loss, TC) alone act significantly against AWD. In tandem though, a lighter car with a less encumbered drive train should have an advantage over a distance.

09-28-2015, 08:36 PM	#1
Dandanbmw Captain 274 Rep 995 Posts Drives: Bmw 640d M Sport Join Date: Sep 2015 Location: Kent iTrader: (0)	330d Rwd vs 335d x drive At Santa pod this weekend I went up against a 335d & 435d and I was very impressed with how they got off the line. My Rwd done well considering but after 60mph my car kept the gap or maybe very slightly gained on them. Could this be down to mine being lighter and rwd as they have 50 odd bhp extra & a little bit more torque? I would had thought they would keep pulling away from me? Attached Images __________________ Current F13 640d M sport in Ruby black with Ivory comfort seats. Number 23 Bmw to date and counting.
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09-30-2015, 09:22 AM	#2
casualDIYer Major 446 Rep 1,369 Posts Drives: 340i xDrive M Sport Join Date: Nov 2008 Location: Toronto iTrader: (0)	Yep, it's the weight and a few other things. Off the line AWD will give that little extra pull from the front wheels but as the vehicle moves faster and faster it goes from passing through a soft breeze to driving the wrong way in a hurricane. The engine needs not only to overcome wind resistance (identical regardless of drive train) but the extra weight as well. Then there is parasitic drive train loss due to the transfer case and front diff. Then you've got traction control on 4 wheels rather than 2 plus whatever farting around the computer imposes managing AWD. None of these things (weight, drive train loss, TC) alone act significantly against AWD. In tandem though, a lighter car with a less encumbered drive train should have an advantage over a distance.
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