Tyre pressures

[JimmyMcMahon]

Good evening.

I have recently had a new C300 AMG Line Premium lease car delivered which has the upgraded 19 inch wheels / tyres.

Front tyres :- Pirelli P Zero 255 35 R19 36Y
Back tyres :- Pirelli P Zero 255 40 R19 93Y

My question is around the tyre pressures as the attached screenshot shows the recommended values on the inside of the fuel cap cover.

It makes no reference however to different tyre sizes so I am not clear as to whether the values quoted on the fuel cap cover are the ones for the standard 18 inch wheels or not.

The only reason I ask about this is because my mercedes me app shows the tyre pressures being higher than those quoted on the fuel cap cover.

Does anyone know what the recommended tyre pressures for the 19 inch wheel configuration are (if indeed the information on the fuel cap cover is not correct)?

Many thanks in advance
Jimmy

 

[whitenemesis]

Tyre pressure is a function of axle weight.
Use the fuel flap pressures as a starting point. You can increase the pressures up to the maximum moulded on the tyre side wall.
It's a compromise between ride comfort, handling and wear. So keep an eye on how they are wearing.

 

[AMGeed]

I read that the tyre pressure is the same, whatever size rim Jimmy. I'd be putting in 36psi front and rear.
There should also be some mention of tyre pressures in the user manual too.


Incidentally, the front tyres are the wrong size on your car.
With 19" alloys you should have 225x40 R19 93Y XL tyres on the front
255x35xR19 96Y XL tyres on the rear if the wheels are staggered (wider at the rear)

Find your wheels in the link below and click on them and scroll down to see the tyre sizes.
All the 19" alloys are staggered, hence different size front and rear.
Mercedes C Class Saloon Alloys (W205) - Alloy Wheels Direct

 

[rf065]

I agree, fronts and rears are the wrong size. Take note though, the recommended 36psi all round on my C Class, has resulted in the centre of the front tyres worn down to 1.6mm while both edges still have 4mm left. I've lowered mine to 30psi after having new tyres fitted, 36 is too high.

 

[JimmyMcMahon]

Thank you all for your replies.

The information in my original post was wrong. The tyres are actually the correct way round (40 on the front and 35 on the back). I wrote them down from photos I took of the wheels themselves and couldn't work out which was front and back from the pictures haha.

There is only going to be 3 people in the car most of the time so would you suggest I deflate the back tyres as the mercedes me app shows that they look to have been inflated (before delivery) to the recommended values for a full passenger load and full boot.

Cheers
Jimmy

 

[400ixl]

Tyre pressures remain the same across the rim sizes as mentioned. Just follow the guidance on the fuel cap and then adjust from there if you feel the need to.

 

[markjay]

I would say that if the 19" wheels were a factory-fitted option (as opposed to a dealer upgrade), then the pressures in the fuel cap apply.

Said that, as others pointed-out, the officially recommended pressure figures are just a starting point.

Higher pressures (and not just when the car is loaded) will result in a more sporty drive, longer tyre life, and better fuel econony. The higher pressures are also recommended for motorway driving.

Lower pressures on the other hand will provide a softer and more comfortable ride.

In either case, do not go to extremes in any direction because it will cause uneven tyre wear and may also be unsafe.

 

[OneForTheRoad]

Should the fronts not be 225 40 19.

 

[rf065]

Should the fronts not be 225 40 19.

Yes.

 

[JimmyMcMahon]

Yes, apologies guys I quoted the tyres the wrong way around in my original post.

To clarify, the 40's are on the front wheels and the 35's are on the back wheels.

 

[OneForTheRoad]

Think its best if you clarify the tyre sizes once again. Not just the profile.

 

[JimmyMcMahon]

Hi mate

For clarity :-

Front tyres :- Pirelli P Zero 255 40 R19 93Y
Back tyres :- Pirelli P Zero 255 35 R19 36Y

I am about to edit the original post too.

Cheers

 

[rf065]

Hi mate

For clarity :-

Front tyres :- Pirelli P Zero 255 40 R19 93Y
Back tyres :- Pirelli P Zero 255 35 R19 36Y

I am about to edit the original post too.

Cheers

Fronts are wrong size, should be 225/40x19

 

[Peter103]

My E350 coupe has 235x35 X 19. On the front.
And. 255x30 X 19. On rear.
What they mean is your fronts at 255 are too wide they think they should be 225, or maybe even 235 like mine,
It's a staggered set up.

 

[JimmyMcMahon]

Sorry again. The correct info is actually here. Third time lucky :-

Front tyres :- Pirelli P Zero 225 40 R19 93Y
Back tyres :- Pirelli P Zero 255 35 R19 36Y

Based on the information above, the tyres are as they should be.

 

[AMGeed]

Well done Jimmy. Got there in the end and all is well.

 

[JimmyMcMahon]

Haha I've had an absolute nightmare in here haven't I?

Cheers for the help all

 

[rf065]

Haha I've had an absolute nightmare in here haven't I?

Cheers for the help all

Don't cheer to soon! Your back tyres are not 36Y I hope!

 

[AMGeed]

Don't cheer to soon! Your back tyres are not 36Y I hope!

I didn't like to mention that......but you did

 

[JimmyMcMahon]

Wow, I assume they are 96Y and I have misread them wrong again from picture. 4th time lucky. Final answer :-

Front tyres :- Pirelli P Zero 225 40 R19 93Y
Back tyres :- Pirelli P Zero 255 35 R19 96Y