Load & speed ratings

[LLCC1975]

Hello all,

 

Apologies if this is a silly question, I know very little about tyres.

 

My 2016 Octavia requires a couple of tyres for the rear. They are 225/45/r17 91w. Doing the ususal searches: Blackcircles etc.

 

Hoping for some guidance whether it is safe and not too reckless to choose tyres that are not 91w? I've noticed that there can be variance in price and performance say between a 91w and a 91y tyre. Is it ok to change a w rating for y tyre etc, or is it best just to stick with a like for like rating?

 

Many thanks.

[Carlston]

46 minutes ago, LLCC1975 said:

Hello all,

 

Apologies if this is a silly question, I know very little about tyres.

 

My 2016 Octavia requires a couple of tyres for the rear. They are 225/45/r17 91w. Doing the ususal searches: Blackcircles etc.

 

Hoping for some guidance whether it is safe and not too reckless to choose tyres that are not 91w? I've noticed that there can be variance in price and performance say between a 91w and a 91y tyre. Is it ok to change a w rating for y tyre etc, or is it best just to stick with a like for like rating?

 

Many thanks.

 

91W can be replaced with 94W,  91Y or 94Y.

 

You might do this if 91W isn't available in the tyre brand and model that you want.

 

For example, Vredestein Quatrac Pro isn't available in 91W but is available in 94V and 94Y. So you would choose 94Y in this case.

 

 https://www.autodoc.co.uk/tyres/vredestein-8714692347313-ap22545017yqpra02

 

https://www.mytyres.co.uk/cgi-bin/rshop.pl?dsco=110&cart_id=2BYOMFmnyrbJ4GxL.110.1836312619&sowigan=GAN&Breite=225&Quer=45&Felge=17&kategorie=6&Marke=Vredestein&Herst=Vredestein&m_s=3&sort_by=brand&rsmFahrzeugart=ALL&Label=E-B-71-2&details=Ordern&typ=R-400850

 

https://www.vredestein.co.uk/car-suv-van/tyre-finder/tyres/product/1/225/45/17/1656-quatrac-pro

 

H speed rating is for speeds up to 210km/h (130mph)

V speed rating is for speeds up to 240km/h (150mph)

W speed rating is for speeds up to 270km/h (168mph)

Y speed rating is for speeds up to 300km/h (186mph)

Edited 10 August, 2020 by Carlston

[LLCC1975]

6 minutes ago, Carlston said:

 

91W can be replaced with 94W,  91Y or 94Y.

 

You might do this if 91W isn't available in the tyre brand and model that you want.

 

For example, Vredestein Quatrac Pro isn't available in 91W but is available in 94V and 94Y. So you would choose 94Y in this case.

 

 https://www.autodoc.co.uk/tyres/vredestein-8714692347313-ap22545017yqpra02

 

https://www.mytyres.co.uk/cgi-bin/rshop.pl?dsco=110&cart_id=2BYOMFmnyrbJ4GxL.110.1836312619&sowigan=GAN&Breite=225&Quer=45&Felge=17&kategorie=6&Marke=Vredestein&Herst=Vredestein&m_s=3&sort_by=brand&rsmFahrzeugart=ALL&Label=E-B-71-2&details=Ordern&typ=R-400850

 

https://www.vredestein.co.uk/car-suv-van/tyre-finder/tyres/product/1/225/45/17/1656-quatrac-pro

Thank you @Carlston for your clear explanation. The options have just opened up!

[Jevpls]

https://www.tyresizecalculator.com/charts/tire-speed-rating-chart

 

W - it means 270 kph and it's way faster than your Skoda can go. Basically you would pay more for higher speed index just because of that.

I might guess that for summer tyres usually in an ordinary store speed index could be around 200 kph. With UK speed limits it's enough. If you are planning to go to Germany (autobahns) and your car is able to do higher speeds then you might consider higher index. Otherwise? More expensive tyres and like previous poster said - you might not be able to get desired tyres with certain speed index.

 

My winter tyres are designed for ~160 kph only. But they are winter tyres (soft ones) and even 140 kph tyres would be just fine.

[Carlston]

2 hours ago, Jevpls said:

...you would pay more for higher speed index...

 

You don't always pay more for a higher speed index. Sometimes the higher speed index is cheaper.

 

Here's a listings on mytyres for Michelin CrossClimate tyres in size 225/45R17. Notice that the highest speed index with the highest load index is the cheapest.

 

https://www.mytyres.co.uk/cgi-bin/rshop.pl?ist_hybris_orig=&x_tyre_for=&with_bootstrap_flag=1&search_tool=&cart_id=I4vh4xg2UruylgMJ.110.376680528&tyre_for=&s_p=&rsmFahrzeugart=ALL&dsco=110&m_s=3&Ang_pro_Seite=10&s_p_=Summer_tyres&suchen=Search+for+tyres&sowigan=GAN&Breite=225&Quer=45&S_Z=&Felge=17&Speed=&Load=&Marke=Michelin&kategorie=6&filter_preis_von=&filter_preis_bis=&homologation=

Edited 27 August, 2020 by Carlston

[Jevpls]

14 hours ago, Carlston said:

 

You don't always pay more for a higher speed index. Sometimes the higher speed index is cheaper.

 

 

Sometimes it is but mostly not. In case when store wishes to get rid of some product, they might sell them cheaper.

[SurreyJohn]

In some cases the tyre manufacturers drop the lower speed rating from their range so have to move to higher speed letter.    
 

Easier (especially for stock) to have one tyre in the size that can cover all speeds, than make 2 or 3 speed variants of each size

 

[26DIPP]

You should use a speed index to cover your car's top speed. You can go higher, but that often means you get a racier tyre which is often more expensive. If you drop the speed rating you have to remember this. Put a sticker into the dashboard or if your MFA allows set the lower speed rating in there and you will get a warning when you approach it.

 

For the Load index you should cover the axle load of your car. You will have a plaque under the bonnet or on the B-pillar which tells you the axle load. Halve this number and that is the individual tyre load you have to have. The tyre load is translated into the LI. If you choose a higher number the tyre will have a stiffer sidewall and a harder ride.

[Ootohere]

Not often you see a speed warning sticker on cars in the UK with Winter / Snow tyres fitted.

 

I used the Winter Tyre warning setting to let me know where a driving ban would be a certainty.

The other Speed warning setting also used at a lower speed.