Rim and Tyre help.

[dru]

Hi Everyone,

Basically looking at getting some new rims fitted to the Skoda Octavia vRS. They currently run 225/35R18 Tyres on a 18" 7.5J ET51 rim. I am looking at getting into some 19" wheels, love the VMR V713's (8.5J ET45). I've been researching and looks like with a 225/35R19 tyre, these will fit nicely!

I thought this was great news and everything was sweet but after looking through tirerack - I found that at 225/35R19 I can't satisfy the load index, which on the current wheels is 92Y. If I move up to the 235/35R19 tyre, I will have a rating of 91Y but other owners have stated that they actually scrub when carrying a full load.

On the Fuel Cap of the vRS it states that the tyre fitted to the car must have a load rating not less than 615kg, Or load index less that 91 and speed rating W.

I don't really have any option but find a rim with a larger offset or smaller width do I?

[Diesel_vert]

That would be correct.

On the other hand, you could just go ahead and fit them anyway - doesn't really seem to deter people.

[dru]

That would be correct.

On the other hand, you could just go ahead and fit them anyway - doesn't really seem to deter people.

I hardly ever carry large loads or people in the back...but down the track it will have some kids in it - so I am not sure what to do atm.

[dylan8]

They currently run 225/35R18 Tyres on a 18" 7.5J ET51 rim. I am looking at getting into some 19" wheels, love the VMR V713's (8.5J ET45). I've been researching and looks like with a 225/35R19 tyre, these will fit nicely!

do you mean your current tyres are 225/40/18...?

This question comes up a lot. depends if you want to stick to the rules or not...

[Prodigy]

Exactly the same problem i encountered dru: http://www.vwwatercooled.org.au/f39/...yre-60119.html

[Gti Dave]

Hmm...bugger didn't really think of this issue. And finding the right style wheels in the correct PCD and width is already hard enough. So does that mean we need to get a minimum of 92Y to at least match that of the factory specs or is 91Y still okay? I'm a noob at this and didn't think about this.

[dru]

So if I reduced the size to a 19x8 ET45 rim, will this mean my clearance is fine or because it's still needing a 235/35R19 tyre I will rub? I found a similar rim in 19x8...otherwise it's back to 18's

[DonJuan]

dru, i am looking at the V710's at the moment for my MKV Pirelli (see other foirum post here: VMR V710's Offset for MKV GTI Pirelli - Help?

i've been getting some adive and it looks as though i should be looking for 8" wide not the 8.5" otherwise i've got a fairly good chance of rubbing and thats using a stretched tyre...

[dru]

If the main issue of rubbing is because of the width of the tyre, is there any reason we cannot increase the thickness? I have had a look and if we run a 225/40R19 tyre, we satisfy the load rating?

[Diesel_vert]

If the main issue of rubbing is because of the width of the tyre, is there any reason we cannot increase the thickness? I have had a look and if we run a 225/40R19 tyre, we satisfy the load rating?

Yes, since a 225/40 R19 93Y XL tyre does indeed exceed the minimum load index.

You may fit any tyre that has a load index of no less than 91, but in reality, you are limited by increases in diameter and rolling circumference.

Fitting a 225/40 R19 tyre would be the equivalent of fitting a 255/40 R18 tyre, which is too big IMO (see below)


Rolling circumference of various fitments:

225/40 R18 = 1943 mm (OEM)

225/35 R19 = 1955 mm

235/35 R19 = 1973 mm


255/40 R18 = 2016 mm

225/40 R19 = 2022 mm

[dru]

And the negative effects of having too large a rolling circumference is inaccuracte speedo, handling ??

I might just cut my loses and go to 18's, use the extra $$$ to lower it.

[Diesel_vert]

And the negative effects of having too large a rolling circumference is inaccuracte speedo, handling ??

Yes, any change in rolling circumference (CR) would affect the speedometer reading (though it seems that accuracy is in the eye of the beholder ) but this isn't that big a deal IMO.

More importantly, an excessive difference in CR will affect how the electronic systems react to vehicle inputs, i.e. ABS, ASR, ESP, perhaps even any electronic differentials (if present), or anything else that relies on calculations based on wheel speed or such.

A tyre with an excessively large CR may also imply large (and therefore heavy) wheels, which would negatively affect ride and handling characteristics due to increased unsprung weight.

Oh, and of course, the wheel/tyre may not even fit within in the wheel arches if you really went nuts.

[peedman]

At stock height and at an offset of 45, you will have no problems running 235/35/19 tyres. I run the same on et40 with 19x8.5 wheels and I havent scrubbed once (on a golf that is).

The biggest differences when going from 18's to 19's is the handling, bumpiness and also how the car doesnt grip the same. The steering is heavier due to the heavier wheels, car is alot more bumpier and the front wheels spin more as there is less flex in the lower profile tyres meaning less grip. All in all while i like the look of the 19's, im going to be downgrading to stock wheels soon since i think itll be easier for daily driving.

[Prodigy]

At stock height and at an offset of 45, you will have no problems running 235/35/19 tyres. I run the same on et40 with 19x8.5 wheels and I havent scrubbed once (on a golf that is).

Can you post a pic of your car if you haven't already somewhere please, interested to see how much the wheels stick out from the guard with those specs.

[peedman]

Here you go mate. Car looks a bit high as the suspension isnt settled yet!

And btw car full of stock wheels in the back and the car didnt scrub once!



Front




Rear




Stock Denvers