Tyre pressures for Pirelli 225 + 245/40 R17 on SLK

[PaulMdx]

I have some (fairly new) Pirelli 225/40 R17 91W (front) and Pirelli 245/40 R17 91W (rear) on my 2004 SLK R170 with AMG alloys. I have googled, looked on the Pirelli site, and searched here, and can't find any mention of tyre pressures for those size tyres on an SLK. My petrol cap I assume lists the standard pressures based on non-AMG alloys, which aren't so low profile as I understand. Any suggestions?

Edit: The tyres are Pirelli PZero Rossos I should have mentioned, which I believe are MB recommended.

 

[television]

Paul the tyre pressures stay the same no matter what size the tyres or wheels are

 

[rf065]

Have a read at this thread and you can work out the correct pressure yourself. This has been discussed before and tyre pressures do not neccesarily stay the same if you change to larger diameter wheels with lower profile tyres.

http://www.carbibles.com/tyre_bible_pg2.html (scroll 3/4 way down page)

http://www.mbclub.co.uk/forums/showthread.php?t=48228&page=3&highlight=tyre+pressure

Russ

 

[whitenemesis]

PaulMdx, are you sure of the profile on the fronts. If it were to be 45 you would have the stanard offering for the Sports Pack option (staggered wheels) and so the pressures would be as listed on the fuel flap

 

[television]

The fuel cap list both standard and larger wide wheels on mine and it stay the same for both.

This advice is also put out by Dunlop, sure if you go down on the profile too much then you may have to increase the pressure a bit to save the wheels, but that is something else

 

[PaulMdx]

PaulMdx, are you sure of the profile on the fronts. If it were to be 45 you would have the stanard offering for the Sports Pack option (staggered wheels) and so the pressures would be as listed on the fuel flap

You're right, the tyres are in fact:

Front: 225/45 R17 94W
Rear: 245/40 R17 91W

My fuel cap does not have multiple figures, but I set the pressure as listed so I guess that's right.

 

[PaulMdx]

The fuel cap list both standard and larger wide wheels on mine and it stay the same for both.

Can I ask what the pressures listed are on your fuel cap? Mine is only a 230K so I don't know if you've got the AMG version and that's why yours lists both?

 

[television]

Can I ask what the pressures listed are on your fuel cap? Mine is only a 230K so I don't know if you've got the AMG version and that's why yours lists both?

The Amg version only uses wide wheels where as mine had the option of wide wheels it says 2.1 to 2.2 front and 2.3 to 2.7 loaded.

We had had this discussion several times,, you should do a search "tyre pressures" and you will see that they do stay the same

 

[rf065]

You're right, the tyres are in fact:

Front: 225/45 R17 94W
Rear: 245/40 R17 91W

My fuel cap does not have multiple figures, but I set the pressure as listed so I guess that's right.

My fuel lid does not have multiple figures either, but my tyres are the same size as yours. (CLK 209)

On the Dunlop site, 3 different pressures are quoted for the CLK (Elegance
16" wheels, Avantgarde 17" wheels & Sport, 18"wheels)

16" Normal 2.1F 2.1R & Fully Laden 2.3F 2.7R
17" Normal 2.2F 2.2R & Fully Laden 2.4F 2.8R
18" Normal 2.2F 2.4R & Fully Laden 2.4F 2.8R

If the pressure listed on your fuel lid are for standard 16" wheels, and you are running 17" wheels, I would raise the pressures slightly. Are you certain the wheels were not standard? If the car had 17" wheels as standard then the pressures as listed will be correct.

http://www.dunloptyres.co.uk/fandp/pressureGuide/result/

Russ

 

[whitenemesis]

Mine is a little more complicated! (sorry about the poor quality)

 

[PaulMdx]

Many thanks to all the responses. Hopefully my tyres are now the correct pressure!

 

[whitenemesis]

If your teeth rattle and you have blurred vision, the pressure is too high

If the car wallows and then squirms under braking, the pressure is too low

Seriously, if you follow the fuel flap recommendations and keep an eye on the wear, you won't go far wrong.