[Yobyot]

Yesterday, New York and New England were surprised by a snowstorm with thick, wet snow. The 6.3" that fell in Central Park in NYC was, according to the NY Times, the most November snow in 136 years.

I was coming home to Boston on the Acela (which was three hours late) due to weather and arrived at Route 128 station about 11pm. This was during the worst part of the storm. Route 128 (actually I-95) north was experiencing white-out conditions. It was scary -- you couldn't see more than about 10 feet in front of the car and the road was unplowed so you couldn't see the lines. Natually, there were the usual "invincible" yahoos driving Silverados and Altimas doing 45 MPH or more. 25 MPH was pushing it.

This is also the first time I've driven my M40i in the snow. I specified 22U at build time because this is my daily driver and it's insane, IMO, to drive on the rubber band tires that come with wheels larger than 19".

I was freaked out by the weather but the M40i did well. I don't have to tell you all that this one powerful vehicle and so using the accelerator gently is the best way to avoid losing traction. The Bridgestone all-seasons were adequate in these tough conditions. Real winter tires would have been better, of course, but I don't often get stuck in these conditions. I usually wait it out -- even an hour or two can make a big difference in road conditions. When a big storm is expected (this one wasn't) major roads are down to pavement pretty quickly as DOT gets to them right away. For me, anyway, there's no recurring need for winter tires.

If you have ZDB very thick, wet snow can cling to the camera between the kidney grills covering the camera and make the system believe there's a barrier ahead. That means that every time you slow down to about five MPH, the automatic front warning system logic believes you are approaching something you should be warned about. PDC comes on, goes straight to "red" and screams at you because it's been fooled by the snow covering the camera. iDrive displays a fuzzy, white "look down" view and all-red distance warning symbols. It can freak you out until you figure out what's happening.

That same wet snow accumulated on the lower front grill radar detector and within about a mile shut down the forward emergency braking. iDrive also displays a warning and places a notification in the messages.

Finally, that wet snow can pile up in the slats of the active grill shutters which remain closed because it's cold. I wish BMW had given us some control of these shutters so in this situation one could open the grills, allowing some heat out of the engine which might also get some of the snow off the front view camera.

You might say, "Dude, just pull over and clean the sensors off." But in conditions like last last night's that's not practical. My car was parked in a covered lot at the Amtrak station. It's about .25 mile from the lot to the highway and the systems were down just after entering the highway.

In short, xDrive is the balls; ZDB is exceptionally sensitive to coatings on the lower grill radar detector, the front camera can fool PDC when covered and as long as you have all-season, non-performance RFTs you will get there.

[SROC3]

I love the elements and driving in all kinds - especially rain and snow. I did my Undergrad in Boston (Wheaton College) and miss all the four years (and four seasons) I spent there.

I look forward to winter season in the California mountains and driving up during a snowfall Woo hoo!!!!@#!@#@#!

[nyalpine90]

I agree, I actually put the car in eco pro and i was upto 45mph unplowed highway at 3pm. I felt comfortable behind the wheel.even though it was a mess, i was able to speed up and pass those drivers couldnt manuever thru snow.

[MechX3M40i]

Thanks for sharing your experience. Having lived in New England for over 20 years (13 at Boston South Shore, a couple years at east of Worcester and 6+ near New Haven CT along I95) your story brings back a lot of interesting memories driving in blizzards and whatnot. I am glad that your M40i held up well with an experienced driver like you.

I now live in the Midwest just North of the M-D line where it does not snow often, and I have the 20" RFT. We got freezing rain from the same system that hit your area, but no ice accumulation on road surface so no issues for us. I am holding out investing for a new set of winter tires and I'll see if I can luck out this season. Keep sharing your snow adventures!

[IM_ALL_IN]

I was scared to bring the car out on the bridgestone alenza's

After the worst, I did go grab a pizza and while reversing out of there, the car freaked out and started beeping while the side view mirror was flashing. I'm thinking that snow must of slid down and briefly covered a sensor.

[BMWZ4]

Thanks for the report. We got a bit of this same storm, but nothing like the 6'' you got, was mostly slushy wet snow. Probably in the 3'' range I think.

Interestingly, and yet not totally surprising, is the behavior of the cameras & radar equipment during winter "storms". It makes me wonder about the future of driver-less vehicles, during winter months in Canada and obviously the northern U.S. States.

[Scottatah]

We also got a smidge of snow (again) that made roads a lil slick and everyone slow down.

I experienced similar chsllegs with the sensors. A front right one must have had snow on it so the car always implied I was near imminent death below 5km/h or what not.

Otherwise, unless on pure ice the traction control and the fact that it’s all wheel drive seemed to make it hard to lose traction or make the vehicle do anything crazy. This is probably a good thing. In my previous rear wheel drive car I’d always give the gas a lil tap to understand how slippery it is out. In this vehicle thst doesn’t really work.

On another plus switching lanes st 70-90km/h where you gotta go through a pile of slush or snow between the lanes does seem a lot more confident with awd!

[frank23]

Probably best to just disable the automatic PDC activation to avoid those issues. I had to do that anyway, as the system would activate just by stopping at a traffic light when it is dark

[BobsM3Coupe]

I thought I read where the front radar sensor had a heating element in it to keep it clear under those conditions?

[kamek]

Agreed. I got caught up in the same storm — while I felt uneasy about the road conditions and other drivers, my M40i was riding steady on my stock A/S tires and gave me a ton of confidence on the road.

[Yobyot]

Originally Posted by BobsM3Coupe

I thought I read where the front radar sensor had a heating element in it to keep it clear under those conditions?

This would be a really excellent feature -- but I don't think it's on my cars.

[BobsM3Coupe]

Originally Posted by Yobyot

This would be a really excellent feature -- but I don't think it's on my cars.

Did you have the rear window defroster on?

Under M40i, G01 service manual, shows that it has it.

https://www.newtis.info/tisv2/a/en/g...709/1VnZ7oP3eg

[Yobyot]

Originally Posted by BobsM3Coupe

Did you have the rear window defroster on?

Under M40i, G01 service manual, shows that it has it.

https://www.newtis.info/tisv2/a/en/g...709/1VnZ7oP3eg

Very interesting. Thanks for the link. It also says

In very poor weather conditions (e.g. snowfall), ACC sensor heating failure may result in restrictions as regards active cruise control availability.

Last week's storm was the definition of "very poor weather conditions". I doubt very much it could've kept up.

To answer your question, I don't remember if I turned on the rear defroster. I usually do, though and now that I know that ACC has a heater, I'll be sure to.

It's fascinating all the stuff that BMW builds into cars that most people never know about.