Lindagail

I may have committed a faux pas, just put all season tires on my GLB35. Mercedes does not sell them, nor do they recommend them over summer tires. However, I live where it can get cold and stay cold for a few days in a row. I bought Michelin Pilot All Season Sport 4 tires, 255/40 20” rims. Ordered them from Tirerack.
im not planning on driving my little car on a race track or over 90 mph. Thoughts?

Serhan

Base GLB 35 comes with 19" A/S. I had 19" A/S with my GLK 350 for 5 years with similar HP and I had no problems including NYC winters. GLK was in Boston with same tires before I bought it...

I was going to change to A/S if I would find the tires for 21". Michelin 21" A/S were available only a few weeks in Dec. I ended getting 20" wheels and Michelin Alpine 4 winter tires before that. I actually like the winter tires much better because of the softer rubber. Winter tires make the car much more enjoyable to drive in NYC roads. I was asking the MB service if it is due to Michelin's tires. He said no and recommended A/S instead of summer tires that the AMG 35 came with. All of these UHP tires are rated to max speed of GLB 35....

Tyre reviews has good comparisons:

Lindagail

I have 20” wheels, came with Continental summer tires

Serhan

Mine have the same Conti summer tires with 21" wheels, 255/35R21...Winters that I bought are 255/40R21. Base tire size is 235/50R19.
https://www.wheel-size.com/size/merc...lass-amg/2021/

Lindagail

So you actually change out your tires by season?

Serhan

Yes, I will do that. That is why I bought the 20" aftermarket wheels with the winter tires so it is easier to change and also the tires will not be damaged each time I swap them... Summer tires are not good under 45F.

Lindagail

The 45 degree rule is what I read. MB dealers don’t seem to believe that, even here in Alabama where folks drive crazy when it snows an inch.

Serhan

I read it recently in the below article:
https://www.autoblog.com/2022/01/21/corvette-blizzard/

Serhan

I saw the graph below in the C63 post which shows the dry grip % vs tire compound temp... Usually tires will warm up after some driving, but still the graph shows the reduced grip with the summer tires in colder temps.... You can find your tire psi and temp in the dashboard.
https://mbworld.org/forums/c63-c63s-...ml#post8496773

Serhan

Following on the topic and graph, I was checking the tire temps last 2 weeks. I found out that the parked tire TPMS temp is -5F to +10 F (when exposed to sun) compared to ambient temperature which includes from below freezing eg 17F to 31F today with snow to 59F yesterday. Driving on mostly cloudy/rainy days (half an hr commute), the tire temp goes +5 to +10 degrees above ambient air during cloudy/rainy weather and up to +20F during sunny days. Front tire warm up more due to front wheel drive bias/weight... Again these might change during summer when the asphalt might warm up more. However considering the average temps for NYC in summer is in low 80's, the summer tires might not be reaching to its optimal grip during my commuting... Summer tires get even more harsher/bumpy in colder fall & spring temps compared to Michelin Alpine 5 winter tires with softer rubber and longer treads... Conti 6 summer tires are recommended for occasional track days, but I don't see the point for GLB... Even Corvette is using Michelin Pilot All Season 4 tires as OEM. I found also Pilot All Season 4 is Tesla T0 OEM tires for my 255/35ZR21 size... I will try Michelin AS also after very good experience with Michelin winter tires. Too bad MB is giving us only the summer tires for 20"/21" wheels...

Here is a good review of Michelin tires that shows how close UHP All Season 4 to 4S:
https://www.tirerack.com/tires/tests...y.jsp?ttid=270




Also I found the original presentation that included above graph. The summer tires are Michelin Cup 2, but it doesn't give info on the all season / winter tires. In the presentation there is a warning about the summer tires below 40F use and storage below 20F:

https://www.pca.org/sites/default/fi...r-TTW-2018.pdf



Again this is reported on the service bulletin from GM as the tire cracks happened during even transportation of GM cars:
https://static.nhtsa.gov/odi/tsbs/20...82862-5448.pdf

I can understand the 40F limit for summer tires, which applies to my real world driving conditions, where the water stays in the dips and freezes on uphill in a S curve. My AS were even slipping in that area...

Only tire performance test vs temperature that I found is below shows good brake performance of Conti 6 summer tires on cold dry pavement, but getting worse braking distance on wet pavement under 54F. Cross Climate tire is Michelin and All Season/Winter tires are Conti:

ILoveNY

I heard many people drive summer tire in snow...

Serhan

Below is updated tyre review test from last year with CrossClimate all weather / all season tire with 3 peak mountain and snowflake (3PMSF) symbol to meet a snow traction requirement of a winter / snow tire. PS 4 A/S UHP is great for dry and wet, but CrossClimate A/S is great for snow and ice in winter. No tire is perfect, so choose your compromises... PS4 A/S slides easily on ice in comparison to Alpin 5 winters. CrossClimates are closer to Alpin 5 winter performance, but lags on wet braking compared to Alpin 5 and dry/wet compared to PS4 A/S...

You Tube

Results are similar to tiretrack winter test, which is missing the winter tire:
https://www.tirerack.com/tires/tests...r.jsp?ttid=270

Tiretrack tests are done in the same track loop, so putting the stopping distances with same car gives a good comparison:

kkoophotography

i have 2021 GLB250 and in NYC. have the 20inc AMG wheel. and using bridgestone alenza AS Ultra $268. works not bad. as thats the only AS tire aside from michelln which is $310