DaveW68

My S600 has the staggered wheel setup. It came with the ugly 18" chrome dish style wheels, which I now use as my winter wheels. On the stock setup with OEM summer tires, the door sticker says 32 psi all around.

With my knock-off AMG 20" staggered summer wheels, I go with 38-40 psi at all corners (after looking at what the S65/63 run on their stock 20's), and they seem to wear pretty evenly.

I have snow tires on my 18" stock wheels at 255/45/18 all around. On the rears with the wider wheels, the middle of the snow tires have worn a lot quicker than the outsides after running 32 psi all around for the last 2 winters. The fronts are perfectly fine with the 32 psi and are very even. Given that the rears have a slightly shorter profile with running 255's instead of the normal 275's, does anybody have any idea what kind of PSI I should be running in the backs to give even tire wear? This is definitely a heavier car than an S550, although most of the extra weight is in the front. I'd go with 275's for the rear, but it's impossible to find matching snow tires at a reasonable price for the staggered setup.

alx

If center is wearing out faster than the edges at 32 psi I would lower to 28 psi. If anything it will help with the rwd in the winter. Or even better- you can keep 32 psi in the back and shove two bags of cement in the trunk. Much better traction and even wear No, I am not joking.

DaveW68

I've always got a loaded golf bag and a case of beer in the trunk. Got to be ready when weather permits.

People who insist that they need their 4matics with all-season tires to get around in the snow because they handle so much better than a RWD car have never driven a RWD car with a decent set of snow tires. Everything from accelerating to stopping to turning is better with the RWD snow tires shod car. But a 4matic with snow tires would be fantastic. Too bad most folks with the 4matics don't spend the money on snow tires when needed.

alx

Oh, no question. We have a saying that with awd you simply get stuck further and deeper, but that is about it lol...

In my mind awd has advantage only if you have to climb a steep incline

DaveW68

When I put on the snow tires 2 years ago, I was concerned that the shorter profile of the rears would affect my speedo. I was quite surprised to see that nothing changed....confirmed by GPS. So I have to assume that the speedo cable is in the front instead of the rear, which was never the case on any of my other RWD cars.

mrbobby

I would be very cautious about running a rear wheel drive car with lower pressure in the rears than the fronts. This will set up a handling problem guaranteed.

DaveW68

Not likely....especially if it keeps more tread on the road.

Jason B

Ok. Explain to me why this warning came up.

DaveW68

Perhaps an issue with your TPMS sensor? If the message doesn't go away after a few miles of driving, check the actual PSI by hand to see if you are getting a good reading. If so, take air out of your tire down to 20 PSI or so and see if the PSI number on your dash goes down within a few minutes . If not, then you may have a bad sensor. If it does go down on your dash, then refill to the correct pressure to see if the error clears. It may take a few minutes of driving to clear the error. If that doesnt do it, then you can try a hard reset be disconnecting the battery for a few minutes.

1bad540

time to put 35 lbs!!!

as far as a rear wheel drive car will drive as good as an awd car... not so. I had snow tires on my stock 19's on a 750 sport. Car actually drove very good in snow, the awd benz tho drives better and is more planted on the road. Ive tried to get it sideways and its sticks, well. I have the conti dws tires on my amg reps in a 20" now and I leave them on all year.

jbarhorst

That warning came up because of enough pressure difference since the last time you reset the "baseline".
While you have the tire pressure readings up you I think you press the down arrow on the steering wheel and it asks you if you want to reset your starting point. Then you press OK to reset, I think.

DaveW68

I had an AWD 300C with new Conti all-season tires on stock 18" wheels. I later got a 300C SRT8 RWD car that I shod with Pirelli Scorpion tires on 19" rims in the winter. Without a doubt the much higher powered RWD SRT8 blew the AWD 300C out of the water while driving in the snow or on ice. It wasn't even close. With the SRT8, I'd be blowing by big 4wd SUV's in any depth of snow and on ice with ease. The AWD 300C accelerated better from a stop than a RWD 300C with all-seasons in snow, but it certainly didn't stop or turn any better than a RWD car.

And that's why you see so many SUV's and AWD cars in ditches during snow storms. Many of those drivers don't account for the fact that the only advantage a 4WD vehicle has is acceleration from a stop....while braking and turning has zero advantages. A good set of snow tires can completely eliminate white-knuckle driving on snow and ice on any car, truck, van, or SUV. All-seasons are pretty much worthless on any level of snow or ice.

1bad540

wtf are u doing driving a 300c?? thats the real question?

DaveW68

Umm....I purchased the 300C new in 2005. 14 months later, I traded it in on the SRT8, which I kept for over 6 years. I absolutely loved that car....and it was loaded with lots of Benz bits, including the same 5 speed trans that I have in my S600. The only downfall to the Chrysler was all of the cheap plastics used in the interior. Otherwise is was a classically beautiful car that was a blast to drive.

bigkev21

It just happened to me over the summer and it was a bad speed sensor.

Jason B

You were correct! That's fixed it! I wonder how many people bring their car to the dealer for this one it was just that simple tire value reset?

amgm5s8

What's up with the coffee cup icon? Never seen

DaveW68

That is an option added in later year W221's where the steering wheel will vibrate if the car senses you drifting into another lane or off the road. It is usually coupled with the blind spot monitoring option.

Others use it as an indicator that they need to stop by Starbucks and waste $5 on a cup of coffee.

klingsor

How did you get the car to display the tire pressure readings on the dash? Mine doesn't show that. When I have a low pressure tire it just gives me the yellow low pressure sign but not the numbers.

DaveW68

When you're at the main menu on your speedo display (the menu that comes up right after you start your car....showing full speedo and odometer), use the left side steering wheel button and scroll twice to the left until you get to the "service" menu. Tire pressure should be the 2nd one down. Usually you have to drive for a few minutes before it will display the psi for each wheel.

Jason B

I took a loaner 2015 ML on a 6 hour trip and that coffee thing came on and a beeping sound. I was very tired and almost dozed off. It somehow knew this. I was never that tired before and it never came on in the S, but I think it does work. There's actually much more involved than you'd think!


http://www.daimler.com/dccom/0-5-121...0-0-0-0-0.html

Even in the most exciting vehicle, a long journey can bring about driver fatigue. An industry first, ATTENTION ASSIST takes note of over 70 parameters in the first 20 minutes of a drive to get to know your unique driving style. As your journey continues, it can detect certain steering corrections that suggest the onset of drowsiness. It then considers a wide array of other factors, from crosswinds and road smoothness to how often you're interacting with the vehicle's controls and switches. If it all adds up to driver fatigue, ATTENTION ASSIST sounds an alert encouraging you to stop for a rest. Between 50 and 112 mph, the system identifies the erratic steering corrections drivers make as they begin to get drowsy and triggers an audible warning, and a "Time for a Rest?"

The video is pretty cool. The also did a test with 550 male and female drivers on the daimler link.