Dutch2

I've had my 2019 E450 for about 3 months. A few days ago a tire pressure warning popped up.

In the warning one tire is 40 psi and is marked OK.

The other 3 tires are 36, 37, and 39 psi and marked low.

The sticker in the fuel door states tire pressure should be 33 psi.

Tires are 245/40R19 on AMG wheels.

How do I find out what the correct pressure is?

Thanks in advance,
D.

JTK44

Just my $.02:

I use the suggested air pressure on the fuel flap plus 10%.

So if the suggested pressure is 33 psi., when cold I keep the pressure at 36 psi. I find the ride the same as at 33 psi, but I get better fuel economy.

You do not state where you live: But here in the NYC area in the fall and winter the pressure will drop due to the cold and I have to "top off" the pressure and bring it back up to 36 psi.

sackboydad

I thought e450’s had staggered tires. My e450 can (AMG like) has fronts that are the same as yours— 245/40R19 but my rear tires are 275/35R19

ua549

The warning indicator is triggered by the difference in pressure between the tires as well as low pressure.

haibieb

Years ago, while working at MB, the tire pressure indicator would be set at a tolerance of 4 psi variation "drop."To date, it appears to hold as well in triggering the alert. Here in South Florida, while temperatures seem to hover around the 60-90's, our RFT do drop in air pressure as well (an average of every 10 degrees drop). I keep ours at around 35 psi year round (cold pressure).

2012 merc amg

Yes, its the deviation. Keep all four tires at 36 PSI cold and you will be fine.