A Class Tyre Pressures

[rhud]

Hello everyone. I have an A Class 150SE (new in Nov 07). I have read here I think - and certainly elsewhere - that A Class tyre pressures are critical for optimum ride comfort. And that in particular pressures at or above the MB recommendation (29Psi) produce a better ride.

As an utterly non technical person, I would have thought reducing the pressures slightly (is making tyres softer) might improve the ride. My interest is that I am a graduate from a BMW 7 Series (big change) and I want to be sure I am giving my A Class (15" steel wheels by the way) the best chance of producing the best result.

 

[Splatt]

Hello everyone. I have an A Class 150SE (new in Nov 07). I have read here I think - and certainly elsewhere - that A Class tyre pressures are critical for optimum ride comfort. And that in particular pressures at or above the MB recommendation (29Psi) produce a better ride.

As an utterly non technical person, I would have thought reducing the pressures slightly (is making tyres softer) might improve the ride. My interest is that I am a graduate from a BMW 7 Series (big change) and I want to be sure I am giving my A Class (15" steel wheels by the way) the best chance of producing the best result.

May well not ! I found this out because my new A 170 came with tyres at 26psi and the ride was awful, it did not ride holes in the road but hammered them . Putting the pressures up to 30 psi brought a distinct improvement. Since then I have played with pressure adjustments and concluded that for my tyre size / make, the optimum is 32 front and 28 rear. I would suggest you go for 30 psi all round until the tyres bed in and then experiment. In doing this a decent digital pressure gauge is essential (Halfords £5)using garage tyre pump gauges you will never get consistant readings.

 

[rhud]

Many thanks for this helpful advice. I will do as you suggest.

 

[hawk20]

Funnily enough I come from an S class so similar to you. I use 30psi all round and find that about right. Sometimes 31 all round to allow for some leakage before I check again!

 

[rhud]

Many thanks for this further info/advice. Obviously the ride characteristics of an A Class are going to be very different from my old BMW 7 Series and I was fully expecting that. However it does seem that experimenting with the pressures can help and I will do that and report back.

By the way, have any A Class owners experienced rattles from the seat belt anchorages on the door pillar? Rattles are notoriously difficult to locate,I know, but I think that's where mine is coming from. Very slight,but annoying nevertheless.

 

[mastereng]

Hi there

I have an A Class A180 CDI with Mercedes 15 inch alloy wheels and Michelin "Energy" tyres. Although the label in the fuel filler cap recommends 30psi, if you check the Michelin website it recommends 29 psi for this particular tyre on an A Class. So, I follow their recommendations and it rides fine - though I think we have to accept that whatever tyre/wheel/pressure combination one has, the ride is not one of the car's strongest points.

 

[hawk20]

By the way, have any A Class owners experienced rattles from the seat belt anchorages on the door pillar? Rattles are notoriously difficult to locate,I know, but I think that's where mine is coming from. Very slight,but annoying nevertheless.

I think I can tell you where that comes from. Fold the rear seat down and then slam it back into the upright position.. Hold seat belt out of way as you do this.

Clever little bit sticks up and shows red if back seat is not fully engaged. And then you get the rattle.

If it is not that, my MB dealer has a great machine. Put car on it, sit inside with engineer. Machine shakes car all over the place and you can seek rattle without having to watch for traffic etc. Brilliant. They reckon it has saved a packet in the time it takes to locate a rattle or squeak.