Down-Shift Question

markmm · #1 10-23-2008, 10:08 AM

Had the 2008 X5 3.0 for about a month now. Seems like when I take my foot off the gas rather than staying in that gear or a "neutral" it seems to down shift immediately slowing down the car. Which is fine when coming to a stop sign, but otherwise seems a waste of gas. Does everyone else's do this?

Thanks!

~ Mark

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mrkbbd · #2 10-23-2008, 10:34 AM

that is normal

dms · #3 10-23-2008, 10:40 AM

Quote:

Originally Posted by markmm

[...] seems a waste of gas. Does everyone else's do this?

What does your econometer say? Pretty sure mine pegs toward the high mpg end when this happens, so it isn't wasting gas. I wouldn't think that BMW would program in this downshift to waste gas when they're trying to eek out the maximum in the EPA test for the window sticker...

rh71 · #4 10-23-2008, 12:38 PM

I'm guessing he means it wastes gas if he has to accelerate to reach whatever point he has to. But mine did this more when it was still breaking in and it also does it sometimes on cold mornings.

markmm · #5 10-23-2008, 03:32 PM

Rh has it. Meaning that if I push it into "N" I could coast a ways. Think of it as if you're driving a manual, and you're cruising in 6th gear, and you suddenly down shift to 4th rather than just taking your foot off the gas or holding in the clutch. Doesn't do it so much above 60mph

Muz · #6 10-23-2008, 04:48 PM

Sure .. and does this also mean you can engage drive whilst doing 40 Say ?

dms · #7 10-23-2008, 11:37 PM

Quote:

Originally Posted by markmm

[...] taking your foot off the gas or holding in the clutch.

I guess I still don't understand. I wouldn't coast in a manual car with the clutch in. I don't do this in either of mine. What's the advantage of taking your foot off the gas to coast if you're not coming to a stop or at least slowing down?

mrkbbd · #8 10-24-2008, 01:26 PM

you do realize that when you coast in gear the injectors are closed but when you have the clutch in the injectors are open to maintain idle

dms · #9 10-24-2008, 08:53 PM

I agree, and the ECU is happy to cycle the injectors on/off for you: if you don't require power from the engine to maintain your speed, then the injectors are off, even with your foot on the gas.

If you are going through a coast/speed up/coast cycle, my guess is that you're using more fuel than if you stay at a constant speed.

markmm · #10 10-27-2008, 09:38 AM

I think the point has been missed. Let's say I'm going to stop in 500 ft, and I'm going say 45 (this is for example, please no speed/distance calculations :P). In my previous car I could take my foot off and cost there with out dropping much speed. Never felt it downshift while coasting. With the X, it drops a gear slowing me down faster making have to hit the gas at 300 ft. in order to make it.

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