What tyre pressure?

[Max Shine]

I have Genuine Staggered Night Edition alloys with 285/30/19 on rears. What tyre pressure should these be at as my filler cap only shows 275/30/19?

 

[AMGeed]

A tyre 10mm wider makes no difference.
Still whatever your fuel cap indicates less a couple of psi.
MB seem to over inflate their tyre pressures needlessly.

 

[whitenemesis]

Tyre pressure is a function of axle weight, so stick within the range given in the handbook or on the fuel filler flap. You can experiment within the specified range to give the best ride/wear/handling compromise. Make sure to maintain any front/rear pressure differential though

 

[Citizen613]

Vehicle manufacturers will always quote the bottom range of pressures suitable for any tyre. This is to ensure the most 'comfortable' drive conditions for the average consumer.

However tyre manufactures will typically quote a wider range of pressures, as a slightly higher pressure will result in a better handling car.

Experiment with pressures ...say up to 6-8 psi above your placarded pressures. Find the pressure that suits your driving the best. This is a compromise between handling and comfort ....your choice.

Also ...if you want to get a bit more technical ...track the wear pattern on the tyres ..say at 3000 mile (5000 km) intervals. Edge wear could mean pressure are tooo low ...centre wear could mean pressures are too high. Caveat: Removing any other factors, like suspension set up, wheel alignment and such.


Easy Guide: Follow your placard in the filler cap, maybe add 1-3 PSI , and your good.

note: always measure cold, Even a short distance will increase heat in a tyre.

 

[Max Shine]

Thank you for all the advice and learnt quite a bit here

 

[sosen13]

a little late, but.. Quick snap from my car, different tyres size incl the ones you ask for

 

[grober]

I suspect that Mercedes in recent years in common with many manufacturers have upped their recommended tyre operating pressures to improve their emission figures by decreasing their vehicle's rolling resistance. I deduced this information from the fact that over the years they have increased the recommended tyre pressures on the same model= same axle loading/speed rating for no obvious reason. I suspect they run their tyres at the upper end of the manufacturer's recommended operating pressure range. So my advice would be to operate at the recommended pressures and anything above that is just going to accelerate wear and give the car a harder ride.

 

[PobodY]

Unless you go crazy with it, there's not much harm in playing with the tyre pressures; it's already quite a dynamic thing as the pressure goes up when they're hot.