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      10-24-2012, 03:33 PM   #38
edx1
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Drives: X1 xDrive35i
Join Date: Oct 2012
Location: Wasatch front

iTrader: (0)

For fun (And this might just be uselss math) I calculated the max mph @ 7k rpm for each gear on the xDrive28i and the xDrive35i for 18" wheels.

Code:
xDrive28i
Gear    1st             2nd             3rd             4th             5th             6th             7th             8th
Ratio:  3.15*4.71       3.15*3.14       3.15*2.11       3.15*1.67       3.15*1.29       3.15*1          3.15*.84        3.15*.67
Output: 14.8365         9.8910          6.6465          5.2605          4.0635          3.15            2.6460          2.1105
7k mph  25.25           37.87           56.36           71.22           92.20           118.93          141.59          177.52

xDrive35i
Ratio   3.64*4.71       3.64*2.34       3.64*1.52       3.64*1.14       3.64*.87        3.64*.69
Output: 17.1444         8.5176          5.5328          4.1496          3.1668          2.5116
7k mph  21.85           43.98           67.71           90.28           118.30          149.17
I can see why the e90 335 could have a faster 0-60 than the f30, once less gear change (Assuming the e90/f30 have same gearing)

I guess the shortened ramble to what I wrote (I can't believe it was that long, sorry) is:

I'm wondering if my experience in test driving the xdrive28 n20/8spd has been experienced by others, or if anyone can explain what might have happened on my drive and that 1.5'ish second transmission response time. Honestely it worried me because when going to pull out onto a busy street or in a moment of need that unexpected 1.5s pause can make a big difference if the transmission can't be relied upon. Test drives are too short and maybe the 35 would do the same thing. I'm wondering what others have experienced.

If I knew my experience wouldn't happen again once I bought the 28, I'd get it and enjoy the lumbar support, and better gas millage. We always want more HP and I can set that aside but lack of power (which the n20 does have) when it's needed, is something that would sway me to the 28 or the 35 if there is true difference.

So if the 8 speed transmission is a bit flaky and always changing gears rather than actually giving you performance, I'd go for the 35. -- On my current 5 speed auto transmission I know how hard I can press the pedal to get the most power from each gear without the the transmission changing gears, and I don't mind "learning more gears". But what I wouldn't want is a transmission that can't decide what gear to be in, pausing for over a second, because there are so many it can choose from, does that make sense?
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