18 Monza question

[Rustybear]

Is 215/35/18 the right tyre size for 18 non OEM
Monza alloys? Ones in have seen are polished/mirrored with black inserts it looks like Sonia this norm on a mk5 or meant for mk6?

[fab5freddy]

225/40/18 would be the norm

Monza shadows from the mk6 

[Tortaruga]

225,40,18 is for oem. Non-oem could be anything so I don't see how anyone can give you a concrete answer.

[Rustybear]

Whats the norm I suppose as either way tyres seem a bit small and may look silly 

[sub39h]

Depending on the width of the wheel (which I assume will be 8in or less) the same size tyre would be applicable as OEM - 225/40R18. Anything else would 1. invalidate your insurance (or massively increase your premiums) and 2. would affect your speedo reading

[xjay1337]

Depending on the width of the wheel (which I assume will be 8in or less) the same size tyre would be applicable as OEM - 225/40R18. Anything else would 1. invalidate your insurance (or massively increase your premiums) and 2. would affect your speedo reading

And how, exactly, would it do that?
Tyre manufacturers, and not the insurance companies, decide what is legal in terms of size - The only exception for that is the speed rating, however as long as the speed rating is higher than the maximum speed of your car, you are fine.

For example Falken certify a 225/40 on a 9.5 which gives quite a lot of stretch. Have an accident and assuming your wheels are declared on the insurance you are absolutely fine and not under risk of any sort of liability or lack of cover because of your tyre fitment.

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Stock tyre size on 18s is 225/40 as has been said. 

I run 215/35s on 8.5 but this is for clearance between my bag and the wheel.. of which there is hardly any.  

You could put a 215/35 on your standard Monza 2 (18") wheel and it would be fine however your speedo would be slightly off (not a big issue as I live with mine every day, plus you can change the impulse value with Vagcom which corrects it) and it would look "odd" as there would be less tyre sidewall in effect lowering your car slightly, however it would also create a bigger arch gap due to less rubber between wheel and arch.

Not recommended unless you know what you're doing and the fact you're asking probably means it's better to stick with the stock tyre size.  

[sub39h]

You are right about tyre companies setting safe limits, but as you point out if you don't declare you aren't insured as I stated, and generally speaking insurance companies are not massively keen on changes to OE spec. Technically speaking, if you even change tyre brand you should be telling your insurance, hence that whole mess regarding winter tyres increasing premiums a couple of years ago. If they were increasing your premiums for something widely considered safe (and something that is mandatory in some EU countries), how do you think they'd feel about a tyre change that was purely for looks sake?

These are insurance companies we're talking about - not something with logic or there to be reasoned with

[xjay1337]

You are right about tyre companies setting safe limits, but as you point out if you don't declare you aren't insured as I stated, and generally speaking insurance companies are not massively keen on changes to OE spec. Technically speaking, if you even change tyre brand you should be telling your insurance, hence that whole mess regarding winter tyres increasing premiums a couple of years ago. If they were increasing your premiums for something widely considered safe (and something that is mandatory in some EU countries), how do you think they'd feel about a tyre change that was purely for looks sake?

These are insurance companies we're talking about - not something with logic or there to be reasoned with

I agree insurance companies are stupid.  

However the bolded section is again something I've heard nothing about and has never, I think, been a problem in any claim situation (to-wit, you have Bridgestone RE070s and refused payout because OEM were Dunlop SP9000 (for example). And the amount of idiots who put budget tyres on to their high performance hatchback and crash, and get payouts, again goes to prove that.

Tyres are subjective. New technologies come along. Anything that is a suitable size and speed rating is completely fine and you don't need to tell your insurers. Otherwise you'd be running round on Uniroyal Crossplys. Which could be interesting.  

I don't think anyone who is into their car modification puts an "odd" size tyre on (such as 215/35) for no reason. The main reason is clearance.

I think winter tyres are different due to the speed rating only being good to about 118mph or something around there. Which to me is kind of irrelevant in the snow and ice but hey-ho

The point is you don't declare TYRE SIZES. You declare aftermarket wheels. The OP posted about non OEM Monzas. So I suspect he has got some non-geniune Monza wheels. Now personally, speaking as someone who has gotten their car insured with all of their mods declared, on a specialist policy, if I bought some non OEM Monzas 18 inch wheels to replace some stock 17 inchers, I would not personally declare that.

[sub39h]

I'm not claiming to be an insurance expert, just going by what I'm told. I agree it is dumb but as far as I'm aware you do have to declare even a change of tyre brand. I am fully aware that the tyres your car comes with is a product of which company the factory made a deal with when your car was being built, and I'm also aware that if you get your tyres changed from your dealer they may well change the brand depending on which tyre manufacturer they deal with, but as it's a deviation from factory spec I was always under the impression that is should be declared. The fact that it's not picked up on is a separate issue.

I didn't declare my change of tyres either, but I have been told in the past that it should be declared - at the end of the day the insurance companies will use whatever they can to not pay out.

Anyway we're getting side tracked. You are right that if the OP is getting new wheels that he should tell his insurance company of this, and irrespective of which brand of tyres they should be safe for the size of wheel and should be rated appropriately for the car