Re: 4.4 SP 19" wheels and a Winter Storm (archive)

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I was @ Tahoe Feb 8th through Feb 11th (the same time as you) in the same X5 4.4 19" config as you, and although I appreciate your optimism on your X5's abilities, your comments about the seemingly amazing traction w/those Michelin 19"s are pipe dreams. I've been driving in Hard Core Wintery road conditions for 25 yrs in all kinds of vehicles and tires, & I can't remember feeling a tire more slippery on snow/ice. Granted we're talking brutal blizzard conditions @ Tahoe, but despite all the BMW high-tech anti-slip, DSC, Hill-descent, ABS, etc (all of which I think is beautifully designed), you still have to have the right tires to translate it to the road's (or snow's) surface!

The DSC was kicking in constantly on the steep snowy roads around Lake Tahoe, but only succeeded in barely getting me TO my short-hop destinations... There was NOT a hint of a feeling of security on the road, except knowing that I had all those air bags around me. The Hill descent and ABS were working overtime approaching stop signs at slow speeds, but still slid seemingly forever and leaving constant questions about whether I would slide into every intersection. I took special note of an old front-wheel-drive Ford Escort w/snow tires blowing by me w/ease and no-slipping!!!!

As a direct comparison, I parked my X5 (thankfully) and went to a dinner meeting w/a friend in a Range Rover w/18" Michelin snow tires on the same roads (and without BMW's high-tech anti-slip) and we stuck to the road like GLUE!!!! In fact their ABS never even activated!!!

90% of snow/ice traction has to do with tires, and the Michelin Diamaris's are SPORTS CAR TIRES, despite the words 4X4 on the side!!!!!

Pretending to communicate to anyone that they EVEN think about driving the X5 Sport package w/19" Michelin Diamaris's in snowy or icy conditions is foolish.

These tires are meant to provide phenomonal performance on dry roads (and they deliver phenomonally as promised), but anyone who drives them in snow/ice conditions should probably call the tow truck 1st, because there is a very good chance you'll need it to remove you, your beautiful new X5, and whoever you take with you from the ditch (if your reasonably lucky).

I love this car, but it is IMPERATIVE that you get an extra set of 17" wheels w/Snows if you're taking it skiing!!!!!

My experience of driving the X5 4.4 with the SP package(19" tires) during extreme winter conditions further deepened my convictions to this vehicle. It never broke traction once. When I needed to apply brakes, the vehicle stopped straight with no slipping. I maintained a safe braking distance so I didn't have to go all out with hard breaking. I kept a gentle foot on the accelerater as well as a gentle touch on the steering wheel. At no point did I get white-knuckled. My "pucker factor" was quite high though, after all, this was a $60,000 experiment I was playing.

AWD:
This feature held the road like it was glued to it. I never saw the RPM gauge race with excess RPMs. Every bit of touque was delivered to the wheels seemlessly. Around corners, uphill and downhill, it seem to track on its own.

Breaking:
Nothing but straight line braking. I even used the breaks, gingerly in turns. Never even got close to other cars or swayed from the direction the vehicle was tracking.

Descent Control System:
I guess it worked. I went down hill pointing in the proper direction. The front in front and the rear in back.

Xenon Lights:
Xenon, Xenon, Xenon. This option is a god saving miracle. GET IT!!!!!

19" wheels:
Michelon 4X4 Diamaris 285/45 R19. These are not mud and snow rated, but you could have fooled me. Perhaps the 5000 lb vehicle weight helps keep these wide tires firmly planted.

Windshield Wiper/Defrosters:
My only bitch. Ice froze on the wipers leaving a good part of my visabilty obscured with frozen water on the windshield. The climate control system defroster would not heat the windshield enough to melt the ice on the windshield nor the defroster. The washer sprayers were buried under 2 inches of show and ice on the hood, and would not deliver the juice. It was not safe for me to stop the vehicle, get out and rattle the ice off from the wipers.(This was the 1st time in 3 1/2 months that I've driven the X5 in inclement weather. It was a tough decission to turn on the wipers. Finally I caved. I may have waited too long, thus my problem.)

Engine/Trans/Drivetrain:
All of these vital components seemed tuned for adverse conditions, except off-roading. My previous car, a 4Runner was a pig on the freeway , but would not get stuck. I though I gave this up. However the gearing ratio and power delivery seemed well tuned in the X5. I hope this is not lost on the 4.6 when available. Also, I used the economical Automatic feature of the Steptronic. Never went into Sport of Manual modes.

Disclaimer:
After reading this append I would not expect anyone to drive in conditions that they are not thoroughly familar with. Driving in mountainious areas under winter conditions can be very perilous.

Route:
California Highway 50 from Sacramento to South Lake Tahoe via Echo Summit, elev: 7,300 ft.
The pass begins 10 miles east of Placerville roughly 3,000 feet to 7,300 ft. in 68 miles. Approxamately 20 miles east of Placerville the route narrows to one lane per direction with no center barrier. The pass offers upgrades, downgrades, and several 90 to 45 degree switch backs.

Conditions:
2" packed snow and ice with 4-6 inches of new snow fall. Winds blowing from Northeast with 20 - 30 MPH gusts. Left Placerville at 18:30 and completed the summit run by 21:30. Nightime driving with visibility reduced to 25 yards, and times near zero due to wind gusts and minor avalanche falls. Total 24 hour snow fall was 12 - 27 inches. Observed several vehicles, including tour busses and tractor trailers that had veered off into roadside ravines. This was at a point called two bridges, where the road is quite simply dowelled to the granite cliff. At three occasions the tree limbs overhanging the road dropped large powder bombs unto the vehicle in front of me. This results in 0 visibility, I couldn't see the road, the vehicle in front, nor his brake lights. I even had two drop on my X5. My maximum speed was 25MPH. Drivers that began thier summit runs from Placerville and started after 21:00, it took them 9 hours to travel the 68 miles. By 05:00 they shut the whole road down for avalanche control. Upon return on Sunday, with simular conditions except daylight, speed was 45MPH.

Chain Controls:
I was cleared through 4 chain control checkpoints. CalTrans was limiting traffic to chains or 4X4 with snow tires. I guess they haven't heard about the X5 19" tires yet, cause they looked and just waved me through. I wonder if they think the 4.4 emblem on the front fender means 4X4.

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