Uniroyal Rainsport 3 sizes.

Bertie Wooster

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Hello chaps

So, I’m needing a new set of rear boots on the old girl and the collected wisdom here seems to be for the much lauded Uniroyal Rainsport 3. Thing is, there seems to a couple of styles available in my sizes.
I’m looking at 225/55/17 and can either chose a 101Y (with a kerbing ring), rated as XL, or a 97Y that doesn’t have an obviously distinct rating. The only difference I can see is that the noise rating on the 101Y is 1db more.
The car is an 05 S320 cdi. Any thoughts on which would be preferable would be greatly appreciated!

Best
Bertie
 

JBell

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Just match the loading to what is on the car now
 

flowrider

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What tyre specification does the owners manual recommend? Go with that.
 

Paul1948

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I have tried both on my W220 320, the 97y gives the better ride and the one recommended in the manual.
 
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Bertie Wooster

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Just match the loading to what is on the car now

What tyre specification does the owners manual recommend? Go with that.

Good ideas chaps! Somehow always forget to read the manual!

I have tried both on my W220 320, the 97y gives the better ride and the one recommended in the manual.

Thanks Paul, appreciate the firsthand knowledge. I did reckon that the heavier loading would result in a firmer ride.

Thanks all!

Best,
Bertie
 

Botus

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its not firmer ride, can alter steering feel, turn in and handling of the vehicle

as in ruin it if you get it wrong
 

Craiglxviii

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its not firmer ride, can alter steering feel, turn in and handling of the vehicle

as in ruin it if you get it wrong
^^^this. Heavier load is required on the rears on estates for instance, but the cars are designed and set up for it. Extra load tyres all around will result in unbalanced dynamics.
 
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Bertie Wooster

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its not firmer ride, can alter steering feel, turn in and handling of the vehicle

as in ruin it if you get it wrong

^^^this. Heavier load is required on the rears on estates for instance, but the cars are designed and set up for it. Extra load tyres all around will result in unbalanced dynamics.

Thank you chaps. Really appreciate the advice. Seems obvious when you think about it, but it’s always best to check!

Best
Bertie
 

Jimbo1959

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First I apologise if I appear to hijack this thread. However as you will read, my comments are pertinent.

I read this thread as the heading caught my attention, I had intended to change on to RS 3's in the future, and it's helped me understand more about the handling of my E350 Coupe and the reasons for the slightly (to my mind) twitchy handling.

Tbh I've always had a full matched set of tyres on my cars mainly so that when they do let go they do so together and usually in a progressive manner which is predictable (and recoverable without major mishap).

I've never had a car so tyre sensitive it would seem, as my E350 Coupe. I'd checked pressures and tried different settings to see if that would help to no avail, and then I happened upon this thread.

Now, the fronts on mine have two 235/40R18 91Y Continental ContiSport Contact 3 (MO) as an axle set fitted with about 4/5 mm of tread on and on the rears there are two brand new 255/35/R18 YXL Continental ContiSport Contact 5's (replaced prior to purchase, so no choice in the boots chosen) also as an axle set. I had thought that with them all being Continentals that there would only be minimal difference in their characteristics but not as much as there is.

The fronts turn in much more sharply than the rears, in fact it almost feels like the rears have stepped out at times, fortunately a little lift and minimal steering correction brings the car back onto the straight and narrow but it's not very confidence inspiring when you are making progress.

I was going to move onto Uniroyal Rainsport 3's when the fronts were due and replace the rears with the same in due course to make up a matched set once again, but the information imparted here is making me a little dubious about mixing makes, due to my experience of having mixed types, of the same make, and the difference in the handling characteristics.

Being the proverbial tight wad Scotsman :p I baulk at waste, however, putting a full set of RS3's on when I still have two reasonably good Conti's on the back, it just goes against the grain :shock: to spend when it appears unnecessary.

Has anyone else changed in stages? How did you find the drive during the crossover?
 

Botus

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my post meant to say

it isn't JUST a firmer ride, it can alter steering feel, turn in and handling of the vehicle


lets start with the basics, if we exclude all these factors

1) wear and tear, (that will make things more pronounced)
2) physical faults, (that many drivers will never notice under slow normal driving - note 80mph on a smooth motorway is still under the term SLOW diving - a wheel bearing with too much slop, a shot damper or a few heavily worn ball joints or suspension bushes)
3) under inflated tyres
4) incorrect road wheels and tyre SIZES
5) wrong wheel geometry

So lets just talk tyre brands and load ratings

Between major brands of like for like size, load rating and cost there are differences but mostly they should be OK to mix and match but, yes they will not be so resolved as a complete matching set. However if you go budget economy from one and top end sports tyre from another you will start to get in a pickle. It will be similar if you go budget brand to posh brand in a mix and match set up.

But if we start to play load ratings it could get more interesting. I don't know enough or how to describe it well, but the issue with using different load rated tyres to those the manufacturer chose, is how it changes "Slip angles". This is the difference "normally" under cornering forces of how the tyre on the road is sitting in relation to the wheel.

if you have substantially different slip angles (especially between axels - front to rear) to those the manufacturer was working with when they choose suspension design, bushing and tyres you could well be driving a death trap that is totally unstable.

If you have 91 on the front and XXL on the back I could imagine this could be very dangerous!!
 
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Jimbo1959

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The tyres on the back show Y XL loading, tbh it's a loading I haven't seen before, and as I said, they were fitted before collection. Basically it was an MOT advisory and consequently I wasn't even consulted, they were the dealers choice. I had expected budgets if I'm honest and was initially quite relieved to see quality tyres had been put on. My only thought at the time was that 'Ok they're not (MO), Mercedes recommended standard, but, they are still Continental's so they should be alright.'
They are not unstable at "SLOW" driving speeds, it's only when one attempts to make "progress" that one has to concentrate 100% and be prepared for .... anything. Most people will only ever drive like this in an emergency situation and never experience that twitchiness.
It's only as I acclimatise to the car and learn it's little foibles that I have discovered it's .... characteristics or limitations, I think is the best word.
The more I learn about the car and it's tyre requirements, the more I think I will change all the tyres to RS 3's and at the earliest possible opportunity. I will need to take care on the twisties.
Oh well, in the meantime it'll stop me speeding inappropriately.
 

sonic

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I have the E350CDI saloon, it came with Pirelli's. Part of the deal was to change the rear tyres on the next service,
they fitted Conti's. Never had a problem with that setup.
About 11 months ago I replaced the fronts with RS3's, again no problems at all.Still running Conti's on the rear.
PS I have the same wheel size as you.
 

Botus

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The tyres on the back show Y XL loading, tbh it's a loading I haven't seen before, and as I said, they were fitted before collection. ….
They are not unstable at "SLOW" driving speeds, it's only when one attempts to make "progress" that one has to concentrate 100% and be prepared for .... anything. Most people will only ever drive like this in an emergency situation and never experience that twitchiness.

I'm not so bothered about the rear being XL rated its more the fact if you really have 91 on the front this is a huge mismatch and 91 is woefully inadequate making things quite dangerous. If you crash it like this your insurer has good grounds not to pay out.

Each vehicle (for given brand, model, wheel type etc.) will be different to the next. Engineers usually get themselves in a mess and have to bodge up some compromise with particular tyres that save the accountants from having a heart attack and the marketing men actually getting something to throw out there for the launch date. They also have brand characteristics they are aiming for.

For example a 90's pug 306 GTI is rather lively at the back, whereas a Merc E class on soggy suspension and high profile tyres will just push the front like mad.

We also get country specific attributes. Italians don't realise it rains, hence Pirellis are dangerous in the wet. Germans iron the road flat each morning and drive like lunatics. Thus the lack of compliance isn't noticed and the bad road noise is irritating someone else. And don't forget, because German cars are set up to stalk autobahns they are built to be very stable and very boring.

If we are talking about your tractor engine'd C class with a couple of tonnes of lead under the bonnet and nothing at all at the back, the steering will be very odd with 91 load rating.

Load ratings are covering lots of stuff, from the obvious like the weight of the vehicle, where the mass is located, the total weight of the load it can have (a seven seater that can do 140mph will be quite different to an MX5) and so forth. But also to suit suspension design, engine torque, how fast the car can go, what type of driver they are targeting and the market it will be used in. I guess the aim is we get consistency across its speed range as well as stability under high speed braking and cornering etc.

Then your comment about at low speed it seems OK, yes forces come with speed and weight. Drive slow and your car's current capability to get wild / odd slip angles aren't presenting themselves yet. Press on and all sorts weird messages and physics will be coming at the car. I should think its a vague wandering disaster, with a penchant for swapping ends.

The Y you mention is a Speed rating (up to 186 mph I think) and the XL load rating on this tyre probably means its a 102. I would think if you don't go above 90mph, don't drive that hard and don't carry 4 passengers everyday, 95 will work well in the UK with 33 psi front 32 psi rear, but being German it should probably have 97 all round and about 36 psi both ends. Don't forget modern tyres run much higher pressures than the old days

I would expect your car to feel much safer if you swap tyres front to rear, and try 32 psi front, 35 psi rear... but 91 is dangerous anyway, you need at least 95
 
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JBell

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Being the proverbial tight wad Scotsman :p I baulk at waste, however, putting a full set of RS3's on when I still have two reasonably good Conti's on the back, it just goes against the grain :shock: to spend when it appears unnecessary.

E-Bay them
 

Jimbo1959

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I'm not so bothered about the rear being XL rated its more the fact if you really have 91 on the front this is a huge mismatch and 91 is woefully inadequate making things quite dangerous. If you crash it like this your insurer has good grounds not to pay out.

Each vehicle (for given brand, model, wheel type etc.) will be different to the next. Engineers usually get themselves in a mess and have to bodge up some compromise with particular tyres that save the accountants from having a heart attack and the marketing men actually getting something to throw out there for the launch date. They also have brand characteristics they are aiming for.

For example a 90's pug 306 GTI is rather lively at the back, whereas a Merc E class on soggy suspension and high profile tyres will just push the front like mad.

We also get country specific attributes. Italians don't realise it rains, hence Pirellis are dangerous in the wet. Germans iron the road flat each morning and drive like lunatics. Thus the lack of compliance isn't noticed and the bad road noise is irritating someone else. And don't forget, because German cars are set up to stalk autobahns they are built to be very stable and very boring.

If we are talking about your tractor engine'd C class with a couple of tonnes of lead under the bonnet and nothing at all at the back, the steering will be very odd with 91 load rating.

Load ratings are covering lots of stuff, from the obvious like the weight of the vehicle, where the mass is located, the total weight of the load it can have (a seven seater that can do 140mph will be quite different to an MX5) and so forth. But also to suit suspension design, engine torque, how fast the car can go, what type of driver they are targeting and the market it will be used in. I guess the aim is we get consistency across its speed range as well as stability under high speed braking and cornering etc.

Then your comment about at low speed it seems OK, yes forces come with speed and weight. Drive slow and your car's current capability to get wild / odd slip angles aren't presenting themselves yet. Press on and all sorts weird messages and physics will be coming at the car. I should think its a vague wandering disaster, with a penchant for swapping ends.

The Y you mention is a Speed rating (up to 186 mph I think) and the XL load rating on this tyre probably means its a 102. I would think if you don't go above 90mph, don't drive that hard and don't carry 4 passengers everyday, 95 will work well in the UK with 33 psi front 32 psi rear, but being German it should probably have 97 all round and about 36 psi both ends. Don't forget modern tyres run much higher pressures than the old days

I would expect your car to feel much safer if you swap tyres front to rear, and try 32 psi front, 35 psi rear... but 91 is dangerous anyway, you need at least 95

Thank you for the information, the warning regarding insurance is taken on board, however, I do drive above 90 mph on a regular basis, granted there is rarely more than me in the car when I do so, it looks like your suggestion of 97's all round would be a better idea. Is there any recommendation you could pass on regarding what could be fitted on the front to replace the 91's and be a better match for the XL's on the back at the moment? Do I just get a pair of 255/40/ZR18 Y XL's for example?

I wouldn't call it a vague wondering disaster, not even when one is pressing on at more than 90 mph, it's just not as planted as my last car which, I must admit, benefited from a full matched set of mid range tyres and felt like it was on rails. I could provoke lift off oversteer when I wanted/needed it rather than having to be reactive, perhaps I just need more practice with RWD after nearly 40 years of predominantly driving FWD.

I would like to hear your suggestions about tyre type/fitment, if possible, to match the XL's though. As it's said "every day's a school day" and when you stop learning it's time to bury you. :D I'd rather find solutions and not suffer the permanent cure. ;)
 
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Bertie Wooster

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So, the plot thickens...
Have just nipped out to check the car before ordering tyres, and low and behold, it's running a full set of XL's all round! No, I didn't put them on, they were new when I got the car two years and 23000 miles ago.
Can honestly say I've not found any untoward handling characteristics, not undue wear.
So what to do? I can't justify replacing the two fronts at this point as they're in great nick (although I admit that would be the easiest thing to do!) Two new xl's on the back?

Best,
Bertie
 

Botus

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if you have a matching set that's a good thing...

if it has 97 as std and you go to 99 all round you will probably only notice a slight decrease in ride comfort and possibly crisper steering

if it has 102 all round it will be different to a std car, but might drive safely, but with more noise, less comfort....

I believe after 102 its 107 and these will be for silly conditions and not sensible for normal use on normal roads by normal people.

you shouldn't listen to me, read the owners manual / email the tyre manu for alternate fitment they have tested and are happy to support.

Jimbo, if I did lots of miles and had a good set of XL tryes I'd get a set of 97 for the other end and cope with it …. BUT remember to get the matching set when you can, not repeat with another set of the same next round
 

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Vagueness and wandering on the front end is often a result of tyre pressures which are marginally too high I find, I drop them a couple of psi which makes all the difference
 

John Laidlaw

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So, the plot thickens...
Have just nipped out to check the car before ordering tyres, and low and behold, it's running a full set of XL's all round! No, I didn't put them on, they were new when I got the car two years and 23000 miles ago.
Can honestly say I've not found any untoward handling characteristics, not undue wear.
So what to do? I can't justify replacing the two fronts at this point as they're in great nick (although I admit that would be the easiest thing to do!) Two new xl's on the back?

Best,
Bertie
Go with XLs on the rear to match them up since you’ve not experienced any handling issues.
 

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