8 hole alloys :

[rob hamill]

can anyone tell me if you can get 17 or 18" ...8 hole alloys. i have an E220 coupe with 15" but would like to upsize but still keep its original look, also if anyone out there has a set for sale could they let me know...thanks.

 

[clive williams]

can anyone tell me if you can get 17 or 18" ...8 hole alloys. i have an E220 coupe with 15" but would like to upsize but still keep its original look, also if anyone out there has a set for sale could they let me know...thanks.

Rob

I don't think that MB offered 8 hole alloys in larger sizes than 16" and I've never seen any aftermarket ones in 17" or 18". They are just not as fashionable as the spoked designs. Why not upsize to 16" and fit 55 aspect ratio tyres say 215x55x16 HR/VR rated on a 7J rim? That will give you the max performance you could hope for out of any wheel/tyre combination and it will look original.

Clive

500E
E320CDIT210

 

[maddog]

Rob

I don't think that MB offered 8 hole alloys in larger sizes than 16" and I've never seen any aftermarket ones in 17" or 18". They are just not as fashionable as the spoked designs. Why not upsize to 16" and fit 55 aspect ratio tyres say 215x55x16 HR/VR rated on a 7J rim? That will give you the max performance you could hope for out of any wheel/tyre combination and it will look original.

Clive

500E
E320CDIT210

I dont agree this thread and the other one where you mention 50% aspect being ideal its not that simple, the wider the tyre the smaller the sidewall needs to be to prevent flex and loss of grip

Low profile tyres dramatically improve the handling of a car the trade off is a choppy ride, if it was all about fashion no one would fit them. To get the grip we want you need wide tyres and if you widen the tyre you need to reduce the profile.

So far in the in the last 4.5 years my 245/45/17's (MB wheels) havent lost traction once apart from on a diesel spill on a roundabout, dry weather handling and traction is fantastic

There is about 1" difference (24.5mm) in the sidewall size of a 45 and 55 profile in a 245 tyre thats about 20%

The difference in the sidewall between a 215/55 and 245/45 is 8mm ie less than 10% not a lot of difference in the ride for an extra 30mm of rubber on the road i know which i did and do prefer

 

[clive williams]

I dont agree this thread and the other one where you mention 50% aspect being ideal its not that simple, the wider the tyre the smaller the sidewall needs to be to prevent flex and loss of grip

Low profile tyres dramatically improve the handling of a car the trade off is a choppy ride, if it was all about fashion no one would fit them. To get the grip we want you need wide tyres and if you widen the tyre you need to reduce the profile.

So far in the in the last 4.5 years my 245/45/17's (MB wheels) havent lost traction once apart from on a diesel spill on a roundabout, dry weather handling and traction is fantastic

There is about 1" difference (24.5mm) in the sidewall size of a 45 and 55 profile in a 245 tyre thats about 20%

The difference in the sidewall between a 215/55 and 245/45 is 8mm ie less than 10% not a lot of difference in the ride for an extra 30mm of rubber on the road i know which i did and do prefer

Maddog,

I knew I was being provocative, but think on this - competition cars treat tyres as performance enhancers, they require them to perform, not to look good, or be comfortable. As part of a comp cars package the builder has the opportunity (specific class rules aside) to vary the wheel diameter, gearing, ride heights etc and the tyres to maximise grip and handling. You will see that the MAJORITY of competition tyres available all have aspect ratios of 50% or above.
It is only where specific class rules require constraints do the builders resort to lower aspect ratios. A good example of this is British Touring Cars where bodywork constraints preclude the fitting of large overall diameters and require the fitting of the largest brake rotors (discs) available. The net result is the biggest wheel with the shallowest tyre.
If you take F1 as the pinnacle of motorsport where the designers are given the most freedom to explore the ultimate then you will find the aspect ratios hover around 45-55%. The suspension designers specifically use the flex in the tyre wall as a springing medium as part of the overall grip package. This was the reason in part why Bridgestone failed to deliver for Ferrari last season - they could not tune the tyre flex into the suspension on the new tyre width rules as well as Michelin and conversely why Michelin competitors all pulled out of the Indy GP - their tyres overheated on the excessively fast corners due to flex.
Some years ago one of the motorsport technical mags did a back to back tyre test on a Fiesta with standard skinny tyres against the optional low profiles on a dry tarmac stage. The skinny tyres won hands down, both on speed tests (it was around 2 seconds per km quicker) and on handling/grip (speed through individual corners).
With regard to width, your tyres are probably the maximum effective width for your heavy car on dry smooth tarmac however, on anything else they will probably not provide the best grip. The potential for aquaplaning in very wet conditions is quite high and their reaction to surface irregularities would be of concern as they cannot mould themselves very readily. Wide tyres are also very susceptible to camber change, which occurs under cornering and in extremis will have lower grip than skinny high profile tyres.
My contention is therefore that the best grip is found with good quality rubber of an aspect no less than 50%, of reasonable width to provide a wet and dry balance, which also has the benefit of providing the comfort sought for 80-90% of the time.

Clive

500E
E320CDTI210

 

[maddog]

You are missing my point you cant say 50% is ideal, its 50% of what??

50% of a 100mm tyre is 50mm, 50% of a 300mm tyre is 150mm

F1 or any motorsport arent good examples as tyres have to do other things with F1 assist with shock absorbing, with BTCC maximise grip and rotor space, with drag racing maximise grip BUT also expand to increase gearing

Its true that a very wide tyre can aquaplane at high speed when the road is flooded but in the real world that hasnt happened the only time my car has ever broken loose (without severe encouragement) was on a roundabout that had diesel spilt on it, i certainly have not felt the need to swap tyres when the seasons change and my car is a lot more powerful than stock . In fact i dont even have problems towing the caravan off wet grass

Tyres have been getting wider and wider and cars faster and faster the two are not unrelated

For example my mum has just bought a Skoda Fabia Vrs , i was looking at it and thinking back to when she used to crititise the "massive" 205/60/13 tyres that were fitted to my 2.8i Capri, the Capri is a massive car compared to the Fabia it was more powerful as well but the Fabia has 205/55/14 tyres fitted as standard and if you watched 5th gear recently you would have seen the Lancia Delta and M3 Bmw lap their test track only a second faster that this modern diesel shopping trolley and thats down to grip!!

Motorcycles are the same my 2003 z1000 has a 190 rear tyre, my 1981 Z1000 had a 130

As for magazine articles i rarely belive them!!

It may be true that in the ranges of sizes fitted to our cars a 50% profile is ideal but simplistic to say it always is, as the wider the tyre the lower the profile needs to be and the narrower the tyre the taller the profile

 

[Apial]

16" or less is best.

Its true that a very wide tyre can aquaplane at high speed when the road is flooded but in the real world that hasnt happened the only time my car has ever broken loose (without severe encouragement) was on a roundabout that had diesel spilt on it, i certainly have not felt the need to swap tyres when the seasons change and my car is a lot more powerful than stock . In fact i dont even have problems towing the caravan off wet grass

In the my real world, as opposed to your virtual ether, my car drives through water flooded tracks in sunken tarmac for miles. Roads so bouncy, even driving at a walking pace would shake your fillings out! My traction control lights up even going over these roads in a straight line!

Lowered suspension, low profile tyres= bad ride comfort, poorer handling over bumpy surfaced roads, and scary aquaplaning. The added fun of scraping the alloys against the kerb is another disincentive. In fact low profiles=fashion before function. The extra width is just to help cool race performance induced heat up. And have you checked your fuel consumption on these tyres? Pitiful.

Perhaps you might have noticed, but race tracks are billiard smooth compared to the real world rutted, pot-holed chipping surfaces that we drive on. Mc Adam would turn in his grave if he could see the roads that the highway dept around here calls tarmac surfaced.

I see the weather forecast is saying snow this weekend, so mind how you go on your wide low profiles with all that extra grip?

 

[television]

I am not really joining this, just my own findings. when I put 7.5j wheels on to my 300 TE it did not hadle so well in the rain and in snow it would not move at all.. My Volvo V70R came with 205x40 tyres and the ride was horrible. Changed to215 x 50, ride now reasable, and I have stopped smashing wheels in pot holes. For a good part it is fashion, One of my garage friends said to me," if anyone can say that the skinny tyres handle better than normal, they should not be driving on normal roads".
That's it Malcolm

 

[rob hamill]

thanks guys

all points taken.....and that was a good wee fight.

 

[DAD190E1990]

http://carbibles.com/tyre_bible.html

This will give all the correct information without any myth's included. Me and some other guys, all time served mechanics, agree this is the best, clearest advice on what's what with wheels and tyres. Hope this helps.

 

[clive williams]

all points taken.....and that was a good wee fight.

Told you I was being provocative. I know what I like and achieve and I'll stick with it!

Clive

500E (326bhp/350lbft/1.7T)on 225x55x16ZR F1s - brilliant!
E320CDIT210 (245bhp/380lbft/1.7T) on 215x55x16VR A2 Alpins - good