First Road Trip... observations
 

I just did a 400k/250mile road trip to San Jose and back. Since I bought the X5 (2002 3.0d, 75,000miles) three weeks ago I'd only been able to drive it around town, so I was looking forward to seeing how it would do on a longer trip.

My route took me along the Pan American highway from 1,500 ft. above sea level up to 12,000 ft. and then back down to about 2,500 ft. during the first 75 miles. Very steep climbs and descents and lots and lots of curves! I came back home down the coastal highway, 60 miles farther but mostly straight and flat.

Going up: There's a slight whistle when I get on the accelerator. Looks from other posts like that may be an intake boot leak... Sounds like a supercharger!
It handled GREAT around the curves and I never felt like I needed more power than what I had in order to pass the busses, tractor trailers or 1970's Datsun pickups with cattle in the back, that I encountered on my way up.

Going down: If what I experienced here is normal, then I may just have to get used to it. Going down hill and breaking, with the car in "D", it would often down shift, (I'm assuming from 4th to 3rd but since the readout only says "D" I'm not positive,) which is fine since the compression helps with breaking, but if I got to a point where I needed a little acceleration it would rev up to 2,800 or 3,000rpm before shifting up. I wound up putting it in "DS" and just shifting manually. Any thoughts on this?:dunno:

Coming home: AWESOME! Speed limit on the coastal highway is 100kph/62mph. I don't go much over since speeding tickets here can run up to $400! Everything felt good. There's another lower mountain pass for about 25 miles before I get home and besides the whistle, everything was good.

I filled up before I left and reset the kpl/mpg gauge. When I pulled in the garage I had averaged 11.9kpl/28mpg! I can live with that!

I think the shifting is normal, its like the downhill assist, saves you from burning up your brakes.

I'm better the 'whistle' you heard was the turbo spooling up. Common sound for turbo diesels in my experience (I've previously owned two different turbo diesel trucks).

I'm better the 'whistle' you heard was the turbo spooling up. Common sound for turbo diesels in my experience (I've previously owned two different turbo diesel trucks).

I hope you're both right. The only other turbo diesel I've driven was a Ford F-250. It whistled but as you can imagine sounded "different".

It does sound like the DOWNHILL program which is one of the adaptive transmission modes of ATC (adaptive transmission control).

See the info below about ATC and the adpative programs when in "D". And it sounds like you found out how to get out of the automatic "adaptive" programming...you put the car in manually selected SPORT mode (D 4 if you have the PRND432 gear shift or D S if you have Steptronic gear-shift feature PRND +/- M/S)...or the STEPTRONIC manual modes (M1 - M5 or M6 if you have the 6 spd tranny).

The 9 adaptive ATC programs are:

1. Extreme Economy (chosen based on driver influence)
2. Economy (chosen based on driver influence)
3. Sport (chosen based on driver influence- how fast/hard you press the accelerator) ;)
4. Winter mode (chosen based on road conditions/wheel slippage)
5. Stop-n-Go mode (chosen based on specific sequence of upshifts/downshifts/brake-stops)
6. Up-Hill Recognition mode (chosen based on high engine load at slower speed)
7. Down-Hill Recognition mode (chosen based on increased road speed with minimal throttle input)
8. Curve Recognition mode (chosen based on rotational difference between right/left front wheel sensors)
9. Cruise Control Drive Program mode (prevents unwanted lock/unlocking of the torque converter & upshifts downshifts when the cruise control is activated)