What Tyre Pressures

[OmniCognateNeutronRangler]

ok, I'm not about to read "all" of this thread but I have a couple of questions:

1) There have been lots of comments about c-class's pulling to the left. Mine does not do this and has Merc fitted continentals. Could tyre choice make any difference to this, perhaps make it more noticable?

2) I have 225 x 50 VR 16's front and rear. I notice in the brochure it says there should be different size tyres front and rear. Is this true of all C-class mercs or only the bigger engine ones (mine is a 2.6 V6)? If they should have bigger tyres are the wheel sizes actually different?

Ta

 

[jberks]

ok, I'm not about to read "all" of this thread but I have a couple of questions:

1) There have been lots of comments about c-class's pulling to the left. Mine does not do this and has Merc fitted continentals. Could tyre choice make any difference to this, perhaps make it more noticable?

2) I have 225 x 50 VR 16's front and rear. I notice in the brochure it says there should be different size tyres front and rear. Is this true of all C-class mercs or only the bigger engine ones (mine is a 2.6 V6)? If they should have bigger tyres are the wheel sizes actually different?

Ta

There are a lot of comments about all mercs pulling to the left, but none of mine have ever done it. Luck of the drawer I guess. Yes, tyre choice will be a factor, as will width, profile, size of the wheels and I suspect most of all, the camber of roads in your particular location.

As far as sizes are concerned 225/50/16's are already far bigger than you need on a C240. To be fair I would say anything over 195 is probably unnecesary on your car or mine, so your 225 or my 245 let alone an even larger rear has more to do with appearance than it does handling. So, whatever yours has, is undoubtably what the marketing boys specced at the build time. The smart has wider rear wheels but that's due to the lack of power steering and the subsequent skinny front tyres. Plus, again, it's a chunky car and would look silly with narrow rear tyres.
The CLS 320cdi has 245 front and 275 rear whereas the same engined E class elegance handles just fine on 225 all round and even dafter, my lower powered 270 has 245's!. Just plain silly really and given my recent headaches, a damned expensive fashion statement!

I suspect wheels would be different, as there is no point fitting bigger tyres unless they are visibly bigger so the small range you have on an individual wheel is probably insufficient.

 

[splang]

my e500 has 245 tyres i think?

Anyone suggest the quitest tyre available as I do get some road noise on roughish roads?

 

[Blobcat]

my e500 has 245 tyres i think?

Anyone suggest the quitest tyre available as I do get some road noise on roughish roads?

What size wheels are fitted? The size of wheel and aspect ratio of the tyre make a large difference to road noise.

 

[splang]

245/45/ 17

 

[Blobcat]

Yes those wheels will make a difference to road noise. What tyres have you got fitted at the moment. You really need some with slightly softer sidewalls, alternatively you could lower the tyre pressures slightly, however you should still stay within MB recommended pressures.

 

[jberks]

my e500 has 245 tyres i think?

Anyone suggest the quitest tyre available as I do get some road noise on roughish roads?

Noise is directly correlated to the gaps between the tread. So, those meaty looking tyres with huge canyons running the entire circumference, such as the Bridgestone Potenza, whilst excellent for dispersing water, aren't so good from a noise perspective.

I've recently fitted Federal 245/45/ZR 17's to mine. They have a more continuous looking pattern with small gaps between each tread chunk and no wide continuous gaps.....and they are very quiet!

So , look at the tread patterns. - Maybe the wife was right after all!

 

[television]

Very good info as always from Jberks, do not forget that it takes energy to generate noise, therefore the quieter the tyre, the more economical it will be.

malcolm

 

[mstar]

unlss u wnt longitivity stay away from the toyos, they wnt last as long as the others.

 

[jberks]

unlss u wnt longitivity stay away from the toyos, they wnt last as long as the others.

I thin you mean 'if you want longevity' - anyway -
I'm doing that experiment at the moment. If a tyre costs 35% less, do you get 35% less wear out of it? And then to complicate things further, if it was a direct correlation (doubtful) are you better off with cheaper tyres anyway as a brand new cheaper tyre is better than a 70% worn top branded one.....
(plus I guess the factor that at some point you have a 90% worn cheaper one against a 60% worn branded..) I think my head may explode!

 

[OlafMaxwell]

I must admit I found the Pirelli P6000 fine, reasonable price and last well enough. The car came with Michelins which were lethal in the wet, rear would break without warning. I think if you are an easy driver the Michelins do not warm up enough.

 

[JPM993]

What about winter tyres??

I'm going through a bit of a dilema at the moment on this topic. I recently moved to a house 'out in the sticks' and I have to do at least 2 miles down some 'slippery' lanes to get onto a major road. In the winter, the lanes are very greasy, wet and slippery. So the question I have is (a) Do I change the E500 and get an ML or another 4x4? Great for the lanes but not as good for the other 48 miles of my commute to work or (b) Do as the continentals do and run a set of winter and summer wheels / tyres?

Are winter tyres an over-kill?

I've always been an Eagle GDS3 fan, but in snow / icey conditions, they were (excuse my French) crap! I guess that most 'summer rate' tyres will be.

I'm looking at the Vredestein Wintrac Xtreme on the current alloys, then stick some GDS3 on some new AMG (style IV) for the summer months.

Thoughts??

 

[jberks]

What about winter tyres??

I'm going through a bit of a dilema at the moment on this topic. I recently moved to a house 'out in the sticks' and I have to do at least 2 miles down some 'slippery' lanes to get onto a major road. In the winter, the lanes are very greasy, wet and slippery. So the question I have is (a) Do I change the E500 and get an ML or another 4x4? Great for the lanes but not as good for the other 48 miles of my commute to work or (b) Do as the continentals do and run a set of winter and summer wheels / tyres?

Are winter tyres an over-kill?

I've always been an Eagle GDS3 fan, but in snow / icey conditions, they were (excuse my French) crap! I guess that most 'summer rate' tyres will be.

I'm looking at the Vredestein Wintrac Xtreme on the current alloys, then stick some GDS3 on some new AMG (style IV) for the summer months.

Thoughts??

In the UK, over the last 8 years of running Mercs, I have never been stuck. Given that MBs are crap in poor weather, the only conclusion is that we just don't get weather bad enough to justify winter tyres. A decent set of tyres with a bias towards water clearance and a decent amount of tread, should cope just fine with 99% of UK weather. Pop the gearbox is winder/economy or whatever, and just be gentle. Worst case, get a set of chains to keep in the boot.

 

[OmniCognateNeutronRangler]

Worst case, get a set of chains to keep in the boot.

are chains and alloys a good combo? Never used chains so I don't know how far down the wheel they go.

 

[Rory]

are chains and alloys a good combo? Never used chains so I don't know how far down the wheel they go.

I was thinking of getting some Autosocks http://www.autosock.co.uk for emergency use, but have never managed to find any user reports.

 

[OmniCognateNeutronRangler]

what a good idea! They look excellent. Like you say, I'd be interested to hear from anyone that's used them (I've never even heard of them). Presumably they would be a bit of a problem if you forgot to remove them as soon as you got out of the snow. Also be a bit worried if they could come off and get wrapped around any moving parts.

Mind you, if you believe the eco-terrorists we'll never see any more snow anyway...

 

[Rory]

Presumably they would be a bit of a problem if you forgot to remove them as soon as you got out of the snow.

If they really work, then I wouldn't even be bothered if they were a 'use-once' type of thing, and then you threw them away.

 

[davidsl500]

I thin you mean 'if you want longevity' - anyway -
I'm doing that experiment at the moment. If a tyre costs 35% less, do you get 35% less wear out of it? And then to complicate things further, if it was a direct correlation (doubtful) are you better off with cheaper tyres anyway as a brand new cheaper tyre is better than a 70% worn top branded one.....
(plus I guess the factor that at some point you have a 90% worn cheaper one against a 60% worn branded..) I think my head may explode!

And of course you have to calculate in the extra cost of fuel if they arent as efficient - is the mpg back to where it used to be JB?

 

[television]

And of course you have to calculate in the extra cost of fuel if they arent as efficient - is the mpg back to where it used to be JB?

The test for measurement or comparison of tyre wear is done with the noise test, since it takes energy to make a noise, the quieter the tyre, the less it wears
This is where one car and driver are used on the same test track, and only the wheels are changed, the same track is wetted and then frozen.


malcolm

 

[jberks]

And of course you have to calculate in the extra cost of fuel if they arent as efficient - is the mpg back to where it used to be JB?

For those new to the forum, I have been experimenting with Federal tyres at £80 each against the Bridgestone factory fit tyres at £160 each. (245/45/17). I was happy with the ride and grip, noise was actually better but I was unsure as to economy which seemed lower though mpg does vary with weather and traffic so only time could really tell.

So, a few months down the line, my answer is - Just about I think. I've certainly seen 45 on an 80+ run so, given that the best I've seen on a 60+ eco run was 48 I'm happy enough.

Wear wise, I've just done a check and after 7,700 miles, I have around 6.5mm left (pessimistic measurement). Wear is even front to back which is odd, given that the front Bridgestones lasted twice as long as the rear bridgestones (and replacement contis), the first time round.

Given that they will have started with around 8mm, that's 1.5mm over 7700 (mostly motorway) miles which would equate 5100 miles per mm or 30,000 miles per set based on a replacement at 2mm. As the £160 bridgestone tyres lasted only 17,000 miles on the rear and 33k on the front, even if wear rate increases dramatically, I should still match the front and beat the rear. So far then, the £80 Federals are way ahead of the £160 bridgestones in all factors.