Tyres

[oversize]

I'm getting increasingly worried that the tyres we need are becoming harder to find.  14s, 15s, 16s and 17s seem to be getting phased out with each passing year by the mainstream manufacturers and it's making the choice of wheels extremely limited as well.  Unfortunately the 14s are getting very rare and expensive now.  Thoughts?

[W116-M117]

It's really an unbelievable situation. There's a combination of more than one factor:

|> any speed the car is declared to do, car makers assign the upper class of speed. That's the situation of my 450SE: max speed 210 km/h (declared by Mercedes-Benz) and tyres with speed code "V" (more than 210 km/h). Why?

|> if the tyre of the car is shared with a famous high performance car makers (i.e., Ferrari...) be prepared that the tyre will increase the price only for that. That's the situation of the Michelin XWX 205/70-14. I'd like to ask what kind of pricing Michelin would get on the /70, if Ferrari mounted /60 or /65 ...

Solutions? I do not know the legal situation in all the Countries, in Italy we have the possibility to mount tyres M+S with lower speed class (for the 450SE becomes "H"): usually M+S tyres are proposed to a lower pricing respect to the all season or summer one, and the lower speed class contributes to reduce more the pricing. Nevertheless, I suppose that first or later M+S tyres will be matter of strategy for the tyre makers, too.

[TJ 450]

Indeed, although 15s are still readily available on demand from conti, yoko, michelin etc. It's the load rating that's concerning. Unless it's a truck tyre, the 14s available now are not up to the task, and in fact are illegal to run on a 6.9. Who still has their tyre placard?

Tim

[Squiggle Dog]

Soon we'll all be forced to be rolling on 20s custom-made from our old wheels.

[jbrasile]

I am very strict with regards to originality but I am a firm believer that this tire discussion with regards to load rating vs speed rating etc  is just too academic.

We ran 205/70-14 T rated tires in the green 6.9 for 4 years (about 15000 km) with zero issues. In fact once the new owner purchased the correct XWX's for the car I ended up keeping his old tires (which are pretty much brand new) and installed them in my 450SEL, getting rid of the ridiculously soft Kumhos. I had my car at 190 km/h for about 20 minutes about a month ago and felt perfectly safe.

The Mercedes Classic Center in Irvine actually installs Harmonys or Defenders on all cars that used to call for XWS's. Their  79 blue 450SEL which is part of the CC's permanent display has them, and from talking to the guys there they have nothing negative to say about using the same tire on a 6.3 or 6.9.

I do realize that in some countries legislation will call for a specific load rating but what do you do if the tire is simply not available anymore or outrageously expensive such as the XWX's for 6.9's? There needs to be some common sense at play here otherwise classic car ownership will become a  nuisance instead of a satisfying hobby.

Just my opinion.

Tks

Joe

[ZCarFan]

Joe, of course if you are counting on a regulatory body of the state to follow common sense then you will likely be disappointed.   

I am in a situation where there is no scrutiny of the tires in use at all (unless you are involved in a tort perhaps, and then only if someone is dead) and the speeds are 70 mph and below.  Speed rated tires are meaningless under these circumstances, though the higher ratings usually goes hand-in-hand with other desired qualities.

The BF Goodrich Radial T/A has a load rating of 1554 lbs so that's awfully close.  They seem to work fine on my W126.  I plan on moving to 15s on the W126 and migrating the 14" steelies to the W116.  Maybe 15s on both, just to access better tires at much better prices.

On my newly-purchased Mustang I have the opposite problem  It is fitted with 255/40/19 Pirelli PZeros so I'm facing the "early adopter" issue there.  There are cheaper replacements available but these things are magic.  Still, less than $300 USD per corner.

[oversize]

Here in Victoria the speed rating must be 'S' or the top speed of the vehicle (whichever is the lesser).  S = 180kmh which is more than sufficient, since our highway speed limit is 110kmh anyway.

The load rating must be no less than what's on the tyre placard.  On a 6.9 that's 1610lbs (730kg each) which is a load rating of no less than 97.  A tyre with a load rating less than that may feel ok, but it's not legal here and will void your insurance policy.  This is despite the fact that manufacturer's provide a large safety margin when they specify a minimum rating.  They say that if you load the vehicle to full capacity and don't fit tyres with the minimum rating they could potentially overheat and blow out.  I'd suggest their legal teams have lots of input into the tyre placard content and here's why.....

730kg x 4 = 2920kg.

2920kg - 1935kg (curb weight) = 985kg payload.

So who's ever gunna exceed a payload of that much?  5 x adults = approx 400kg.  That leaves 585kg left for luggage....

Interestingly the manual says the Gross Vehicle Mass is 2420kg (depending upon options), which is 500kg less than what the 97 rated tyres can carry.  The manual also says you can carry 60kg on the roof (presumably with the correct roof racks fitted).

So in summary with 5 adults and 85kg of luggage you'll be right on the maximum GVM well before you reach the maximum load capacity of the tyres.  And that rules out towing....

Note that my maths has been known to fail me on several occasions!   

[oversize]

BTW 205s aren't legal on a 6.9 which specifies a minimum width of 215 (mm).  You can fit wider tyres, but not anything narrower than what's specified by the manufacturer for that model or series.  Potentially it can cause 'adverse' handling characteristics

[jbrasile]

Interesting discussion...

Let me throw this into the mix... what do you guys think Mercedes, Ferrari, Lamborghini, Porsche etc took into account when selecting a tire during the development of their cars in the 60's, 70's and 80's? Did they look at speed rating (especially important in Germany) or load capacity?

The reason I ask is if you look at a Ferrari, Lambo or 911,  from that period they were cars fit  only for 2 occupants, with very  limited luggage carrying capacity, however these were vehicles capable of maintaining speeds in excess of 200kph all day long, therefore they needed a tire that would withstand the heat generated by these high speeds regardless of their loading characteristics. If you check any modern high performance tire available  in a V, Z or W speed rating none of them has a load rating higher than 96.

Looking at 6.9's today, there are NO 14inch tires with a load factor of 97 or more except for XWX's, not even Vredestein has them. So I guess most 6 9's in Australia and other countries which enforce the load rating policy should not be driven on public roads,which is simply absurd!

Governments have a way of creating and enforcing certain rules and regulations that are written by people with zero common sense and usually very little technical knowledge which is very unfortunate for us classic car lovers.

I heard in Essen than certain cities in France, Holland and the UK are starting to ban older cars due to their higher emission levels, especially Diesels.

I wonder if perhaps these tire rules could be "bent" a bit under  a Classic Car registration scheme.

Anyway, great topic!

Tks

Joe

[ptashek]

The Mercedes Classic Center in Irvine actually installs Harmonys or Defenders on all cars that used to call for XWS's.

I think the folks in Fellbach install Fulda tyres. Can't remember the exact model now, but there was a shot of a W116 for sale by the Classic Centre, with Fulda's on, in one of the last few MB club's "Gazette". Looking at fulda.com, the only matching tyre I can find is an ECOCONTROL HP, 205/70R14 95V. I've seen the Vredestein Sprint Classic 205/70R14 95V mentioned a few times as well. Neither would (officially at least) suit a 6.9 though.

When the time comes, I'll just try to find 15" or 16" rims that don't look like made for a pimpmobile, and will call it a day. I may be lucky, as my dad recently found at least two 7Jx15 Pentas, with matching Ronal bolts, in his treasure trove of car parts. He recalls having a full set at some stage.

[jbrasile]

ptashek,

That is a great tip regarding the Fulda's !!! Just checked their website and as you said they carry the EcoControl HP in 205/70VR14.

Probably the best solution for a 6 9 is to go 15, if you don't want to spend the $$$ for 15 inch Bundt's then 126 rims will do, and I really don't think the car looks that bad with those installed.

It looks like there are no official Fulda dealers in the US so that is probably why Irvine and others end up using the Harmony/Defender.

I guess for all 107's, 116's and 126's that use 14 inch wheels the Fuldas might be a great option depending on price. They can probably be imported into the States without much of a hassle. I run Harmony's on the 1980 450SEL and love the handling and ride.

Tks

Joe

[Bandolero]

Agh!
On my 6.9 tyre placard it shows; 215-70-VR14.
This means it's a V rating.
It doesn't show the load rating and nor does the owners manual.
I can get V96 tyres for my 15" rims but I'm trying now to see what's available in the 215 14" rims.
I may be able to get the car re-placarded at an engineer that can do this. I'm just waiting for him to ring me back.
I'm having trouble getting 14" tyres as the BFGs are no longer available they said. Bugga!!!!

[Bandolero]

Hah!
It pays to ring the correct people to find out the facts.
Here in South Australia you can fit a lower speed rating to your car provided it is 135kms/hr rated or above.
The engineer (who was recommended to me by the Transport Authority) said you can even fit retreads to a Porsche 911 if you want and it is legal.
The load rating will be ok as well as he said that so long as the speed rating is ok, the load rating will be ok too.
He also said that if the insurance company tried to void a claim because they say the speed rating is lower, they will be told by the Ombudsman to contact the engineer I spoke to anyway, so no problems.

Now, all I want is a set of tyres.

Oh, and I found out on the net that the BFGs are still made, so much for that tyre company's info!!!

[oversize]

You're right about retreads but I wouldn't use them after some nasty experiences in my younger days....  The ADRs say some can be as low as 100kmh max.  Many fitted to taxis are 140kmh.

Wrong about speed and load ratings being proportional.  They're often inversely prop.  High perf = low profile = less air = less load.  Many cheap performance tyres have quite low load ratings

[oversize]

If it's a 6.9 your placard should say 1610lbs