0-60 335xi sedan with all season tires

Probably somewhere between those two extremes. I don't know that there is one real number because of differences in timing and human error. I would take those two numbers and average them for a probably 5.0-5.2 second 0-60 time under normal conditions.

In the User's manual of any 3-Series BMW there should be the 0-60mp/h (or 0-100 km/h) values, for all models (X or not, Automatic/manual gearbox). That was the case for my E46 and it was the only way for me to know, as no magazine or website reviewed this particular model (330XI Touring automatic gearbox). So if you don't own a 3-Series, stop any driver on the road and ask to see his manual ;)

I have read that the 335i is 5.1 automatic but you will lose a little bit of that speed because of the 4 wheel drive. I have a 335i coupe with a dinan upgrade, and it can keep up with m3 s and rs4 s. You can make it that fast with just a dinan turbo boost.

well the 335xi sedan is only 200 pounds heavier ive actually seen the 335xi sedan take both coupe and sedan rear wheel and if you were to look them up both it will you tell with the 335xi coup just a second faster then both coup rear wheel auto and manual guest its a big different when u have all 4 wheels turning than having two in the rear check it on u-tube

Most of it depends on the driver and gear engagement. Unless you are racing it, what does it actually matter? Beside, racing a X model should be off-road anyway, so mute point.