Tyre replacement query ml270

[Dan2k7]

Hi guys can anyone offer advice on what is best size tyres to replace on an ml270?

Car currently has 275/65/17s on it and handling is terrible. Have read that a lot recommend switching to 255 or even 235 wide. Can anyone recommend which size and would it be ok insurance wise?

 

[Wighty]

Your car manual should list other available wheel size options

 

[JBell]

Car currently has 275/65/17s on it and handling is terrible.

Can you be more specific?

 

[EmilysDad]

..
... . Can anyone recommend which size and would it be ok insurance wise?

Insurance wise you need the correct tyre size .....

 

[Mark A]

Our old w163 270 was on 255/65-17 from the day we bought it. That was one of the options from new and should be in the handbook.

 

[Dan2k7]

Can you be more specific?

Hi sorry for the late reply. The car tramlines badly. The steering is rather vague.

 

[Dan2k7]

Our old w163 270 was on 255/65-17 from the day we bought it. That was one of the options from new and should be in the handbook.

Thank you I will have a look. Even 255 would be an improvement.

 

[kid-jensen]

Hi sorry for the late reply. The car tramlines badly. The steering is rather vague.

Vagueness generally points to suspension/steering play or maybe misalignment.

The usual cause of tramlining on tyres that didn't tramline when new, is just wear. There's not enough rubber in the tread to absorb road imperfections and white line lumps. It's the tyre's way of saying "replace me, the legal limit is approaching".

I used to have 255/55 on my ML and now have 285/50. Both exhibited a slight amount of tramlining when new, and loads of it when getting to the end of their life.

IMHO, the wider tyres are MUCH smother riding and have better grip. The downsides are.....well, none really, except the price. The BIG advantage is that they protect my precious alloys against the occasional "female-parking" manouvre, that all of us are guilty of occasionally.

At least, that explains the large numbers of ropy old alloys on ebay...

 

[Dan2k7]

Thanks for that Paul, the tyres still have 5mm tread on so have fair bit of life in them. As for the steering/suspension play its due mot in couple of months so I will see if anything is highlighted but I believe a few people have down sized tyres and found it to be a much better ride.

 

[JBell]

Hi sorry for the late reply. The car tramlines badly. The steering is rather vague.

You basically have balloon tyres which will enhance body roll and tramlining is probably as much the roads as the tyres

 

[oigle]

I put mine on 235/65/17 many years ago partially due to tramlining on the original 255's. Improved the ride and steering noticeably. Standard tyres on the 164 were 235's which says something.

 

[kid-jensen]

Going down to bicycle tyre widths is all very well, but the centre of gravity as about waist-height, so the ML struggles with changing direction. To get around the slip-angle problem (or at least minimise it) you need more rubber on the road.

Tramlining is a minor inconvenience that's worth living with in exchange for a 6 foot 2 inch car that actually handles pretty well, given sufficient rubber on the road.

The best handling SUVs at present (Porsche and BMW) have enormously wide tyres, you couldn't make this type of car handle even vaguely well on bike tyres...

Alternatively, don't drive on any roads with corners...

 

[LostKiwi]

Going down to bicycle tyre widths is all very well, but the centre of gravity as about waist-height, so the ML struggles with changing direction. To get around the slip-angle problem (or at least minimise it) you need more rubber on the road.

Tramlining is a minor inconvenience that's worth living with in exchange for a 6 foot 2 inch car that actually handles pretty well, given sufficient rubber on the road.

The best handling SUVs at present (Porsche and BMW) have enormously wide tyres, you couldn't make this type of car handle even vaguely well on bike tyres...

Alternatively, don't drive on any roads with corners...

Actually I think thats not correct. Slip angle is more about sidewall height and deformation of the tread and sidewalls than about tyre width on its own.

A narrow tyre on a larger rim should be able to handle as well as a wide tyre. There is no increase in traction from a wide tyre as width just changes the shape of the contact patch not the size of it.

If the same sized rim is used then a wider tyre will result in a narrower sidewall hence contact patch deformation will be less when cornering (reduced sidewall flex). Range Rovers corner very well on comparatively narrow tyres (255/55/20) or even the narrower M&S size (235/65/19).

 

[JBell]

Car currently has 275/65/17s on it and handling is terrible.

They are too big, they should be 275/55 R17 109V

Look here

http://www.alloywheelsdirect.net/me...lass_w163_alloys/17_mercedes_tegmen_wheel_920

 

[kid-jensen]

Lost kiwi wrote:
"There is no increase in traction from a wide tyre as width just changes the shape of the contact patch not the size of it."

I'm sure I'm being a bit thick here, but surely if that were true, Formula 1 cars would have bicycle-width tyres for reduced drag?

 

[LostKiwi]

Lost kiwi wrote:
"There is no increase in traction from a wide tyre as width just changes the shape of the contact patch not the size of it."

I'm sure I'm being a bit thick here, but surely if that were true, Formula 1 cars would have bicycle-width tyres for reduced drag?

No its true.
http://forums.mercedesclub.org.uk/i...er-rear-wheels-why.161981/page-3#post-1526235

 

[oigle]

I think that perhaps on a perfectly smooth road a wider tyre will give better sideways grip but who travels on perfectly smooth roads? F1 maybe. Bumps and irregularities will upset wide tyres more than thinner ones and anyway, as I said, MB figured that 235's were the perfect standard fit for 164,s so guess they agree with me. My experience was that 235's gave more accurate steering on bumpy roads. I still use them and get very good mileage out of them even though I tow a van. 70000km out of last set of Yokohamas.

 

[kid-jensen]

The article was very interesting to someone who's spent as much money on tyres over the years as I have.

However, the fact remains: for better cornering grip (straight-line grip is a lot less important, unless you are Jeremy Clarkson in a BMW 1 series), you need to go to wider tyres.

Phew, looks like all those Formula 1 designers are not stupid after-all!

Perversely, unless there was loads of standing water, wider tyres would have probably kept Jeremy on the runway, and saved him the cost of a new pair of Levis...

As for certain BMWs high-speed instability, thankfully on here, nobody needs reminding how bad that is.