Minh Do

The AC system in my 2018 E300 seems to not blow icy cold air compare to my mom's Lexus RX350 or even my old 2014 Accord. I took it to the dealership and they found no faults with it. Maybe the German do not equip their vehicles with powerful AC system?

nycebo

Agreed. You have to really turn the temp up or down to effect change

rustybear3

I sure do miss the old R12 freon. This new stuff is crap.

That stuff (R12) was icy cold in a car. I don't care what your temperature was in your auto, the air conditioners back before 1994 would cool it down in a matter of minutes. No need for the bs air cooling seats.

Lanzz

My 2017 E300 AC is just on the border of crap. On really hot days, you have to fiddle with it and turn the temp down to LO and the fan way way up to get anything cool out of it. I had two hemi powered cars before this - a Chrysler 300C and a Dodge Challenger, both would freeze you out after about 5 minutes of running the AC. I love my car, but the AC is woefully under-powered.

Minh Do

Is it just a German thing in general or just Mercedes? My lease ends soon and I dont want to go with German again if that's the case.

gearFX

Just curious, besides manually setting the airflow (fan) speed (1 through 7, etc.) has anybody noticed a difference in air conditioning performance (or comfort, which is what we're really after) by adjusting the "Climate Style" (buried under VEHICLE > CLIMATE CONTROL > CLIMATE MODE)? There are 3 available modes:

Have any of you (including the OP) noticed an appreciable difference between these settings?

ua549

I keep my AC set on 72° F and the system on auto. I have not had any issues with those settings. I do have IR blocking glass. A long time ago I posted about AC outlet temperature. IIRC It was quite low. That said the AC sizing limit on lowering temperatures is somewhere around 25° F below outside ambient levels. That is similar to residential AC.

rraisley

I agree! I remember the old days when you could buy 1 pound cans of R12 for $1 at K-Mart, and service your AC yourself. Now, you need a license, and half the stuff they use (like in my small drinks frig) is flammable!

Bobby4919

I agree with UA549. The PAF option does help.... along with legal window tint on the side and back windows. Second summer with my 2017 E300 here in Central Florida and the A/C has performed just fine. No complaints.

donaldm241

no AC cooling issues here is SW Florida even on 93F days. I do not have the added glass option

whoover

I find that the system works much better if all the vents are completely open. If you throttle some of them down, the climate control cranks the fan way up to compensate and cooling suffers. With the vents open and adjusted up, down, left or right as best for comfort, I only adjust the driver temp (with SYNC on). With that configuration it gets as cold as I want it. In fact, I usually have to crank the temp up to 72 to keep from freezing, even on hot days with no IR glass.

I thought the AC sucked until my car was in for service and I got another E-class as a loaner. It ran way colder and I figured out why.

nycebo

I think it is meager. My old e350 wagon seemed to work better. When it got warm or during the past heatwave, 72F did get the car cold.

vic viper

Fun fact, as of ~2018 models Daimler uses CO2 as refrigerant, the medium operates at much higher pressures (up to 200bar) but is safer than the toxic and flammable R-1234yf

CaptainE

Why anyone would shut down vents when looking for maximum cooling I don’t know.

I also use SYNC and my 2019 cools off well and I live in Phoenix and have the acoustic glass option and uv ‘tinted’ windshield was done when I got my windows tinted after delivery. Huge difference from stock.

When the desired temp is reached, I turn down the fan, not increase the temp. It stays on LO in the summer.
Wasabi?

rraisley

Another thing that can definitely make a difference, especially in the car's temperature at startup, is the paint color. I've measured from 120 degrees for white to 160 degrees for black for the hood surface temperature of cars sitting in the South Carolina sun. I'm not saying the car won't cool properly if it's black, only that it may take a bit longer.

chassis

Lots of factors in play. The most easily measured are air temp and velocity coming out of the registers. Other subjective factors are sound (noise) and the control button/dial logic chosen by the car manufacturer. Sensitivity, or lack thereof, of the controls to user inputs gives an impression of system “power”. Not unlike accelerator pedal vs fuel delivery mapping.

My wife’s G01 BMW has noticeably cold air con. My W166 has what I consider to be average air con in terms of overall performance. I will measure register temp next week when I have some time.

The_Judge

Ditto. In fact, on cooler days I up the setting to 75 because the car gets too cool.

whoover

On a road trip. Just drove 300 miles in 90+ air. Had to put temp up from 72 to 74 to keep from freezing. Got to our stopping point for the day and it was HOT outside. Regular glass.

It's definitely the best AC I've had, including in 9 MB models going back to 1983. So these reports of inadequate AC are very surprising. I wonder if there are different versions somehow.

TPAbnz

Has anyone tried to direct a/c to the footwell? It seems like very little air on that setting.

Minh Do

What fan setting?

Minh Do

What fan setting are you running? If you're blasting the fan speed on max of course its.gonna be cold and annoying as hell on a commute.

whoover

Auto, and it is usually fairly low. When I had some vents partially closed it was so high I couldn't hear the media but opening them all fully made a dramatic difference and auto blows at one of the lowest settings after the car cools down on start (a couple of minutes at most).

CaptainE

I do that too. No reason to bump it up to the mid 70s in auto when manual and lower flow works well. I can’t stand air noise so auto bs doesn’t work for me.

wasabi?

madtrader

I had a white 2012 w212 sedan that was a rolling refrigerator. I loved it. I traded that in for a black 2018 e400 wagon last August and noted that it seemed like the A/C didn’t cope with the heat as well. I switched to a white 2019 e450 wagon this past March (with the PAF package) and thus far its handled the summer heat way better than the black wagon.

Turbocharged

I'm a complete novice when it comes to auto cooling systems, but I'll proceed anyway. I've been searching the web and finding no information about any M-B vehicles that actually use the CO2 refrigerant. The old refrigerant, R134a, will be replaced, it's environmentally nasty. It seems that R1234yf is the refrigerant that most manufacturers want to use as a replacement. M-B had initially declared that R1234yf was flammable and consequently they would continue using R134a. M-B declared that they would be moving to R744, a carbon dioxide (CO2) based refrigerant, and said they were planning to use R744 in some European S and E Class autos starting in 2018. However, other studies have since come out declaring that claims of R1234yf flammability are exaggerated, and in October 2018 the European Commission ordered Germany to enforce the current refrigerant regulations and stop permitting the use of R134a. In July 2019 or so Germany ordered Mercedes to recall their R134a vehicles and comply with current regulations. M-B will provide an answer in a couple of months. So it looks like there might be a limited number of M-B R1234yf vehicles out there, but I can't find any M-B vehicles that actually use the R744 refrigerant nor any firm commitments on what future models would use R744.

Update: I have found at least one example of an S-Class car with R744.

Update 2: Found out that there were approximately 30,000 MB and VW vehicles on the road using R744 in 2018. (Accelerate America magazine, Oct 2018, p. 24).