Increasing tyre profile from 50 to 55?

[skyship007]

[QUOTE=Spetsnaz GSh;2204446]Well, to be honest, in this circumstance, we aren't talking the police with tax payers' funding here where they can use as many tyres as they want and change them when the weather changes again because money isn't really an issue.

Most people will not do the "enthusiastic" police style driving or braking, let alone in these extreme conditions and also most people don't have the money to change the tyres between the seasons so in that respect, a summer tyre like the Uniroyal Rainsport 3 is a better all year all rounder, and if it means you can get your tyre in the correct size (not impacting the ABS algorithms) then even better.

The RainSports have superior wet stopping distance and wet traction than a lot of equivalent and some superior tyres so I don't see why you want to make them seem like such an inferior product.

You get what you pay for with common tyre sizes and most Michellin tyres last longer and have thicker sidewalls which helps a lot if you hit a pot hole.
Winter tyres have better breaking distance figures when the road temp is below 7c in comparison with same brand summer jobs.

If you want to use all season tyres, nothing will beat Goodyear vectors, although I have not seen the figures for the new Michy all season yet.

On average Conti and Dunlop are top dogs in braking distance and traction terms and my Dun summers cost 5 Euros less than Conti sport contacts.

You might not be interested in wheel spin or aquaplaning figures, but buying the best tyres is a real good potential cost saving, as every inch counts in a emergency stop.

Personally, I run Pilot Sport 4 - known for being simply one of if not the best road tyres you can buy and I will admit they are a cut above the uniroyals, but not everyone wants to spend crazy money on tyres and if given the choice, I would run RS3s over Michelin Winters all day.

Who makes the Pilot Sport and does it say made in Germany on the side ??

[ww1dm1]

Originally Posted by skyship007

The ABS self check will detect a difference fore and aft if you are daft enough to fit different radius tyres thinking you own an F1 race car.
The self check will also check RPM vs wheel spin, so that might not allow 18 inch wheels as the max OEM fit for one particular sport model was 17 inches.

Just to remind all would be boy racers that you only have a fully valid insurance if you fit one of the tyres listed in the owners handbook.

One typo in a previous post of mine inferred 14 inch wheels are OK, THEY ARE NOT, the minimum is 15 inch wheels.

I didn't think fitting differently sized tyres is even in question, that's just stupid. What would RPM vs wheel speed would even tell you, though? The dependency is different in every gear, and the gear is not being watched on MT. And why do it at all?

[Spetsnaz GSh]

Originally Posted by skyship007

Who makes the Pilot Sport and does it say made in Germany on the side ??

We are talking tyres here and you have never heard of the Pilot sport 4? come on dude ;-)

Michelin Pilot Sport 4 - They are mix compound tyres with specific functional elastomers. The sport contact 5 and equivalents are old hat compared to these.

These are not comparable to winter tyres I admit but these are still the best sports tyres IMO and I don't intend on changing them just for winter.

Just a bit about the PS4: Better Wet braking and dry braking than a Bridgestone Potenza S001, Conti Sport contact 5, Dunlop Sport Maxx RT , Eagle F1 Asymmetric 2, Pzero and Hankook V12 Ev02 K120.

Like I said, personally, I am very interested in the things you state:

"You might not be interested in wheel spin or aquaplaning figures, but buying the best tyres is a real good potential cost saving, as every inch counts in a emergency stop."

who isn't lol?

[V40Vinnie]

I have Goodyear Efficient Grip Performance in 205/55R16 91V VERY VERY twitchy

[960kg]

baggy798

Quote:
Originally Posted by skyship007 View Post
...otherwise you will need to contact your insurer about using non standard tyre sizes.
No you don't. Yes you will as you have to fit manufacturers recommended sizes

Quote:
They might not agree as it causes speedo errors and sometimes effects the basic handling.
Seeing as speedos typically under read 2-3 mph, 205/55's could actually increase the accuracy. Handling differences won't be noticeable.
Volvo speedos are accurate and you will SEE the diference. The handling WILL be affected.

Quote:
In a real silly case it can even upset the ABS causing an ABS fail warning light.
No it can't. Yes it can, in fact in the correct car handbook for your model it tells you how to re-adapt so the ECU can correct ABS sensors readings for correct speed reading, even if you fit the narrow spare wheel it has to be re-adapted.










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[skyship007]

Originally Posted by Spetsnaz GSh

We are talking tyres here and you have never heard of the Pilot sport 4? come on dude ;-)

Michelin Pilot Sport 4 - They are mix compound tyres with specific functional elastomers. The sport contact 5 and equivalents are old hat compared to these.

These are not comparable to winter tyres I admit but these are still the best sports tyres IMO and I don't intend on changing them just for winter.

Just a bit about the PS4: Better Wet braking and dry braking than a Bridgestone Potenza S001, Conti Sport contact 5, Dunlop Sport Maxx RT , Eagle F1 Asymmetric 2, Pzero and Hankook V12 Ev02 K120.

Like I said, personally, I am very interested in the things you state:

"You might not be interested in wheel spin or aquaplaning figures, but buying the best tyres is a real good potential cost saving, as every inch counts in a emergency stop."

who isn't lol?

Ahh, so the Pilot Sport is a top of the range Michy all season. Good news if you like all seasons.

[Jebus]

Originally Posted by skyship007

Ahh, so the Pilot Sport is a top of the range Michy all season. Good news if you like all seasons.

Not quite, since there is the ever increasing drive for low rolling resistance to give quiet and fuel efficient tyres, grip has suffered so the latest ranges of High Performance summer tyres use several compounds and tyre wizardry to give both low rolling resistance and better grip.

So they will also do a better job at lower temps, but nothing like a good winter tyre but will be slightly less of a massive drop off in grip that you got on the high performance summer tyres of previous generations when the temps drop.

[ww1dm1]

Originally Posted by 960kg

Quote:
In a real silly case it can even upset the ABS causing an ABS fail warning light.
No it can't. Yes it can, in fact in the correct car handbook for your model it tells you how to re-adapt so the ECU can correct ABS sensors readings for correct speed reading, even if you fit the narrow spare wheel it has to be re-adapted.

Could you elaborate this one, what exactly would be adapted and how is this procedure carried out? The only warning I've seen in the owner's manual about the spare is to turn off the DSA just in case, as the wheel diameter is different.

[skyship007]

The ABS self check occurs at only a few MPH after you first move off, that's why the ABS warning light is the last one to go off. If the engine RPM does not relate to the ABS sensor RPM, then the speedo will be in error, so some type of change to the ECU progran tweeks the scaling factor.
If the resulting scaling factor is out of safe limits, then the ABS light would not go out and the system is disabled.

[ww1dm1]

Originally Posted by skyship007

The ABS self check occurs at only a few MPH after you first move off, that's why the ABS warning light is the last one to go off. If the engine RPM does not relate to the ABS sensor RPM, then the speedo will be in error, so some type of change to the ECU progran tweeks the scaling factor.
If the resulting scaling factor is out of safe limits, then the ABS light would not go out and the system is disabled.

As I already mentioned, relating ABS sensor RPM with engine RPM is kind of pointless, as this depends on the gearing. And this relation isn't really needed for calculating vehicle speed, ABS sensor RPM is enough.

And the scaling factor is necessary of course, as there are x40 versions with differently sized wheels. Though I thought this was programmed with dealer hardware and software.