Ride quality on the vega 19” alloy wheels

[Rajj]

I hope you all had a relatively good Christmas, under the circumstances.

 Just wondering if the ride quality (especially on those small road imperfections) be improved on the sport-line model? I have reduced tyre pressure but found only marginal improvement.

Edited 26 December, 2020 by Rajj

[SurreyJohn]

Sorry, but in blunt terms, without spending money, the basic answer is no.

 

In theory can change tyres or shock absorbers, but ultimately 19 inch wheels are to look good on billiard table smooth roads and showroom floors.  The electronic DCC adaptable dampers (if fitted) can mask road imperfections.
 

Unfortunately, the looks part of 19 inch wheels is a case of style over practicality, there is a reason why versions of Karoq come with 17 inch wheels (and 16 inch in some European countries), and it is because you can fit deeper sidewall tyres to absorb road imperfections.

 

There are basically 2 ways to absorb road imperfections, primary suspension (rubber tyres sidewall) so fine ripples don’t get to the metal wheel rim, and secondary suspension (which is really for bigger bumps) which is the springs between wheel and body.

 

This has come up before, but many posters would prefer an option to specify smaller wheels with all season tyres instead of large wheels with summer tyres

[Rajj]

Hi @SurreyJohn!

thanks for coming back. i wonder if  DCC could be retrofitted? 

[Carlston]

2 hours ago, Rajj said:

I hope you all had a relatively good Christmas, under the circumstances.

 Just wondering if the ride quality (especially on those small road imperfections) be improved on the sport-line model? I have reduced tyre pressure but found only marginal improvement.

 

What size tyres have you got fitted? 225/40R19 or 225/45R19 ?

 

If you have 225/40R19 tyres, then fitting 225/45R19 tyres will improve the ride...especially if you lower the tyre pressures by 3psi (0.2Bar).

 

The reason that you can lower the tyre pressures by 3psi when changing from 225/40R19 to 225/45R19 is because the higher sidewalled tyre can support the same amount of weight using 3psi less tyre pressure. This is reflected in the different load indexes of these two tyre sizes. 225/40R19 has a load index of 89 (580kg) @ 44psi, whereas 225/45R19 has a load index of 92 (630kg) @ 44psi. For example, 580/630x35psi=32psi. To do the maths, you form a multiplier by taking the load index of the original tyre and divide it by the load index of the replacement tyre. You then use this multiplier to multiple the original tyre pressure...which gives you your new reduced (and more comfortable) tyre pressure.

 

The 4x2 Karoq when fitted with 19" wheels has 225/40R19 tyres, whereas the 4x4 Karoq when fitted with 19" wheels has 225/45R19 tyres.

 

The standard tyre options on new Karoqs in the UK are either 17" or 19".

https://cc.skoda-auto.com/gbr/en-GB/trimline-scenic?_ga=2.210707863.348432214.1608996413-0a2cf681-cbb9-4a54-988d-1bb2bc4df8a8&activePage=trimlines&color=K4K4&configurationId=&extraEquipments=&id=GBR%3Bskoda%3B2021%3BNU73B5%3B0%3BGYO2YO2%3Bmda20200804034704%3Ben-GB%3B%3B62001%3B62061&interior=AD&modifiedPages=&snapshotVersion=e0456e00-f767-4c80-854f-216feb5b3ce1&trimline=NU3|SE6206162001&visitedPages=

 

19" Crater Rims 8Jx19 ET45

https://eshop.skoda-auto.cz/cs_CZ/kolo-z-lehke-slitiny-crater-19-pro-karoq/p/57A071499++HA7

 

Even with a change from 225/40R19 to 225/45R19, the 19" rims on the Karoq are 8J. This is the width of the rims, ie. 8".

 

This is wide for a 225/40 or 225/45 tyre and stretches the tyres' sidewalls which makes the ride harder. As a comparison, the Skoda Octavia will often use a much narrower 7J rim when fitting 225/45 tyres albeit in 17" format. Even with the 225/40 size, the Octavia still uses narrower 7.5J rims.

 

Edited 26 December, 2020 by Carlston

[Rajj]

Hi @Carlston

i have  225/40R19. i will opt for  225/45 when i change the tyres. 

thanks a lot for the info! 

[kenfowler3966]

Won't that make the speedo under read as the overall rolling radius has increased? Hence potentially illegal.

[Ootohere]

When checked it will be obvious that the Speedo is over reading now, so the speedo might become nearer accurate with the slightly bigger circumference / total radius tyres fitted, and it is easy to check if it is and not under reading.

[Phutters]

1 hour ago, kenfowler3966 said:

Won't that make the speedo under read as the overall rolling radius has increased? Hence potentially illegal.

 

Indeedy.

 

Easy to check here.

[Ootohere]

@Phutters  Those are very good.  That shows the difference if the speedo was actually showing the correct speed for a new tyre fitted of an actual size and inflated fully.

 

The thing is that @Rajj could check the car now on the tyres it arrived at him with from the factory at 70 mph and no way is the car going to be doing 70 mph.

More likely 67mph.

But checking things as they are are a good way on knowing.

[kenfowler3966]

I did read somewhere that the sportline uses 235/40 tyres so not quite as bad changing to 225/45?

 

Not sure if correct though?

[Phutters]

10 minutes ago, kenfowler3966 said:

I did read somewhere that the sportline uses 235/40 tyres so not quite as bad changing to 225/45?

 

Not sure if correct though?

 

Our MY2021 Sportline 2.0TSI has 225/45 19s. They're no more likely to make your dentures fall into your lap than the 225/45 17s on the A3 it replaced.

 

Well I say that, but I can't confirm it absolutely; the car has been at the dealership since the 16th of November (three and a half days after driving it excitedly away from the showroom, brand spankers) with its innards hanging out courtesy of a rear differential which was faulty from the factory.

 

The replacement diff has been on back order since the 19th of November.

 

Long story. 

 

Long wait.

 

Diminishing patience.

 

Sorry, I've wandered off-topic.

 

The closest replacement tyres (in terms of diameter, and therefore speedometer accuracy) are 255/40 R19s, but they are getting on for an inch wider than the stock 225/45s. While the extra inch in width would undoubtedly help in terms of protecting those whopping alloys, I'm not sure if they would be a bit too wide.

 

It's a kind of academic question at the moment anyway - I'm in no mood to shell out six hundred quid (and the rest) for four new tyres when the original ones have barely had the little rubber nubbles worn off them.

 

 

.

[Carlston]

2 hours ago, Phutters said:

Our MY2021 Sportline 2.0TSI has 225/45R19s.

 

The closest replacement tyres (in terms of diameter, and therefore speedometer accuracy) are 255/40R19s, but they are getting on for an inch wider than the stock 225/45s. While the extra inch in width would undoubtedly help in terms of protecting those whopping alloys, I'm not sure if they would be a bit too wide..

 

According to ETRTO, 255/40 is too big for an 8J rim.

 

245/40R19 might be a good choice. 245/40R19 has the same load index as 215/55R17. 215/55R17 is a standard size on the Karoq.

 

The outside diameter of 245/40R19 is almost identical to 225/55R17. 225/55R17 is a standard size on the 4x4 Karoq.

 

Outside diameters

215/55R17 668.3mm

235/40R19 670.6mm

245/40R19 678.6mm

225/55R17 679.3mm

225/45R19 685.1mm

255/40R19 686.6mm

235/45R19 694.1mm

 

The Kodiaq uses 235/45R20 on 8J rims, so 235/45R19 on 8J rims could be an option for the Karoq.

 

235/45R19 is 1.3% bigger than 225/45R19.

 

Edited 26 December, 2020 by Carlston

[kenfowler3966]

But not a type approved size for the car so not allowed and you would have to get approval from your insurance company as well?

[Carlston]

7 hours ago, Rajj said:

Hi @Carlston

i have  225/40R19. i will opt for 225/45 when i change the tyres. 

thanks a lot for the info! 

 

Just to add to the 225/45R19 suggestion...the Kodiaq has a 7Jx19 ET43 rim option. These look similar to the VEGA 8Jx19 ET45 rims from the Karoq. See the two links below for photos of the 19" CRATER rims from the Kodiaq.

 

CRATER 7Jx19 ET43 Rims from the Kodiaq in Matte Black

https://eshop.skoda-auto.cz/cs_CZ/kolo-z-lehke-slitiny-crater-19-pro-kodiaq/p/565071499++ZG6

 

CRATER 7Jx19 ET43 Rims from the Kodiaq in Anthracite

https://eshop.skoda-auto.cz/cs_CZ/kolo-z-lehke-slitiny-crater-19-pro-kodiaq/p/565071499++ZG6

 

225/45R19 tyres fitted to 7J rims will ride a lot softer than when fitted to 8J rims.

[Rajj]

ever since I bought the karoq i stopped hitting more than 70 mph. max i would have done is 75 ish. the tyres are so sensitive to the road imperfections that its impossible to get a smooth ride on the motorway. Where as, i could easily hit 78 on my previous i30 without any jolts in the cabin.