E Class. Tyre pressures

[Tramper]

Afternoon
Having only had my car a month now I thought I'd check the tyre pressures having 4 new tyres fitted when I brought it. Now on the car it says 280Kpa all round (1-3 passengers) this seems a lot to me the tyre size is 225/55/17. The onboard monitors system says they're on 230Kpa. How accurate are these systems?

According to my calculations 280Kpa is 40.6 psi. Which seems really hard.

Colin

 

[400ixl]

Should say on the inside of the fuel flap what PSi you should be using.

 

[MercedesDriver]

Just do as it says on tin. My 17" tyres are on 300kPA.

 

[John N]

Afternoon
Having only had my car a month now I thought I'd check the tyre pressures having 4 new tyres fitted when I brought it. Now on the car it says 280Kpa all round (1-3 passengers) this seems a lot to me the tyre size is 225/55/17. The onboard monitors system says they're on 230Kpa. How accurate are these systems?

According to my calculations 280Kpa is 40.6 psi. Which seems really hard.

Colin

My Filler Lid states 220Kpa 32 PSI for your Tyre Size!

Now follows the question:

Do you check the Pressures hot or cold!

 

[Salal]

Most E-class tire pressures are around 32-35 psi depending on rim diameter and which axle. Also the amount of load you have in the car which would probs be slight higher by a couple of psi.

Check your hand book or inside the fuel filter cap that’s where’s you should find your values for your car.

 

[CaptainChaos]

Pump them up cold to the recommended pressures and try it. Many people remember their first car had 32psi all round and think all subsequent cars will be exactly the same!

 

[rf065]

Pump them up cold to the recommended pressures and try it.

I did that with mine, 36psi front & rear is recommended on the fuel lid. After 12 months, the front tyres feel brick hard & the centres are wearing fast with no wear on the edges. Now running them at 30psi & they feel perfect, time will tell how they now wear. Manufacturers are stating unrealistic pressures in an effort to get the ultimate mpg figures out of them, far too hard for our roads though.

 

[190]

I agree they are increasing pressures to eek out the last fraction of an MPG. On average a 10% increase in pressure gives 0.8% improvement in MPG. Big deal, I'd rather the car had a better ride and even tyre wear. I reduced my pressures by 5 % and I've had no abnormal wear problems over 16000 miles and a better ride.

 

[Scooby_Doo]

Mine should be 250kpa 3 up + luggage . Much better ride @ 230 kpa on 19" runflats. When it came back after being in for a service a few weeks ago the 18"s were pressured up to 270 kpa.

 

[johnsco]

40.6psi does seem very hard.
I've run various E class models for years, and the recommended pressures have usually been different front/back.
Recommended pressures have varied between 28 and 35 depending on the car / the load / and whether the tyres were snow tyres.
As a rule, I do tend to follow the manufacturer's recommendations.
They should know.

 

[rf065]

As a rule, I do tend to follow the manufacturer's recommendations.
They should know.

They do know, but have a different priority than most owners and are only interested in max mpg's.
They couldn't care less how long your tyres last.

 

[CaptainChaos]

30 sounds way too low for a modern heavy car, presumably on run flats. But if that's what you want to use, crack on. Incidentally max load rear tyre pressures on mine are 48 psi!

 

[Salal]

I use 33psi on my W211 estate when not loaded and find it a nice balance between comfort, wear and mpg on continental tires.

 

[such01]

according to my flap - tyre pressures all round are 39 psi. I ran the fronts lower (unintentionally) at 34 psi and they wore out on the inside and outside edges.
Needless to say I'm running at 39 psi now

 

[350cls]

When I first got this new to me s212 e250 the cars ride was fantastic I think the pressures were 32 34 psi all round something like that. I inflated them two weeks ago to 39 all round and I dislike the ride quality on those higher pressures. I think I'm going to revert back to the previous tyre pressure the car was running. Definitely didn't feel as crashy/ harsh. This is on cross climate tyres too.

 

[OneForTheRoad]

When I first got this new to me s212 e250 the cars ride was fantastic I think the pressures were 32 34 psi all round something like that. I inflated them two weeks ago to 39 all round and I dislike the ride quality on those higher pressures. I think I'm going to revert back to the previous tyre pressure the car was running. Definitely didn't feel as crashy/ harsh. This is on cross climate tyres too.

By the time they get heat ,it'll be more like 42 psi. Pressure is set so the footprint of the tyres sit as much as possible on the road . If it states 39 psi , I'd opt for 34/ 35 cold as a starting point.

 

[350cls]

By the time they get heat ,it'll be more like 42 psi. Pressure is set so the footprint of the tyres sit as much as possible on the road . If it states 39 psi , I'd opt for 34/ 35 cold as a starting point.

Thanks OFTR good advice,I'll keep that in mind.

 

[Fastcar155]

On my C207E400 recommended tyre pressure was 37 psi cold.

 

[190]

The problem with "recommended tyre pressures" these days is they are often artificially inflated to reduce rolling resistance and improve mpg.

My VW Golf is an extreme example. It's a blue motion model with 205/55 R16 tyres and a recommended pressure of 39 PSI with no alternative comfort pressures listed. Other models of Golf with the same size tyres have comfort pressures as low as 30 PSI. This illustrates that you can no longer rely on the recommended pressure having been optimised for the load capacity of the tyre, weight of the car and good ride comfort. As I prioritise ride comfort over saving some fraction of 1 % on fuel use, I don't use 39psi and err towards something much closer to 30PSI.

 

[350cls]

Driven the car on a good long journey today all different road surfaces and can definitely say I prefer the ride/comfort on the lower pressures. Happy days. Enjoying the car/ride again. Not sure if it's just me but I think the 211 is more forgiving than the w/s212 gives. It's not nasty the 212 but I think that 211 it's that little bit more forgiving on a ride quality factor. But the 212 definitely feels more modern to drive. All in all well happy with the e250 s212 SE.