As I've got a rear tyre that resembles a 50p piece and sounds like a wheel bearing thats done 200k miles with no grease I've decided to buy a full set to replace the Avon zz5 tyres that are fitted. Now on 18" standard vrs rims so the tyres currently are 225/40/18. As i seem to have a bit of arch room on standard springs i was considering swapping to 45 profile for A, comfort and B to fill in as mentioned gap. Has this been done before and if so how does this affect the speedo accuracy? Any pics would be great too. 

 

Thanks in advance.

Your speedo will under-read by 3.4%.

I don't have a problem with what you are suggesting but not sure how the nit picky insurance underwriters treat a vehicle with tyres that are not same size specification on tyre plate. Gives them a possible argument.   They maybe expect you to declare a modification. Ridiculous I know for a 5% change in sidewall height and probably higher load ratings!

Good shout didn't think of insurance. Nothing is decided as yet just thought I'd throw the idea to you guys see what pros or cons there are.

5 hours ago, meaty101 said:

As I've got a rear tyre that resembles a 50p piece and sounds like a wheel bearing thats done 200k miles with no grease I've decided to buy a full set to replace the Avon zz5 tyres that are fitted. Now on 18" standard vrs rims so the tyres currently are 225/40/18. As i seem to have a bit of arch room on standard springs i was considering swapping to 45 profile for A, comfort and B to fill in as mentioned gap. Has this been done before and if so how does this affect the speedo accuracy? Any pics would be great too. 

 

Thanks in advance.

My rear tyres went like a 50p, but I had the rear alignment checked and altered after fitting new tyres and it never did that again.

Have you had your alignment checked?

As above, I'd wager that there's an alignment issue to cause weirdness like that...

 

For the cost of four decent tyres I'd spend the ~£60 for a proper four wheel alignment otherwise you could end up with buggered tyres after a short while all over again...

 

A speedo under-read of 3 or 4 percent will likely be well within the over-read that all cars have...

Skoda revised the rear camber settings on the mk2 because of the 50p issue:

 

Sorry for going a little off topic

Edited 10 February, 20179 yr by Bogwoppit

I havnt had the car too long. The two front tyres were fitted about 6 months before i bought it. I factored in a wheel bearing on the rear but it turned out to be tyres. The car also needs some bump stops fitted to the rear shocks so the plan was to fit the bump stops, set of tyres all round then an alignment. As for the tyre profile, can anyone see any issues with  45's?

6 minutes ago, Bogwoppit said:

Skoda revised the rear camber settings on the mk2 because of the 50p issue:

 

Sorry for going a little off topic

Looks like a common problem I've not heard of this. I'll check my inner and outer edges again tomorrow. My steering wheel is off centre too.

Hello Mike you ok buddy? Definitely will once all jobs are done. You reckon your alignment was knocked out when you removed your rear shockers Mike is that right?

back on topic what are the tyre choice limits for standard 18s? this is something that I wanted to ask too, can you go wider? can you increase profile?

Apologies for straying off topic. Yes good questions. I'm sure 45 profile should be ok without scrubbing. Width I'm not sure. Rims are 7" wide but the limiting factor will be inner arches etc on full lock or rear full of passengers.

I find the ride quite harsh, probably more so than my mk1 vrs so would be good to know or if anyone else has done so.

 

Considering downsizing to 17s that's how bad it is and i'm only 25!

I've no chance at 45 yo then!! You should drive a mk2 Leon Fr see how you go with that. A comfy ride they are not!! Sold that got back into an Octavia. They're like a Rolls Royce in comparison.....

13 hours ago, Shadows Entity said:

I find the ride quite harsh, probably more so than my mk1 vrs so would be good to know or if anyone else has done so.

 

Considering downsizing to 17s that's how bad it is and i'm only 25!

I find the ride firm but not overly. Have you thought about fitting better dampers? I fitted koni fsd to my Fabia VRS and they were very impressive. Firm but nicely damped and along with eibach springs, totally transformed the car. 

I will either fit FSD to this Octy or Bilstein B6.

Not really tbh. I'm happy with the ride as it is compared to my old Leon it's a magic carpet ride!! Just thought an idea while changing all 4 tyres to go with the bigger sidewall. It's more to do with the fact that there does seem to be plenty of room in the arches for 45's. My neighbour done it a while ago on his TT although they are 17". The car  does look a lot better.

Edited 11 February, 20179 yr by meaty101

As someone with a Superb II on 18s, I've done some digging on alternative tyre sizes as well. Based on their shared origin, I'd imagine most of what goes on the Superb II goes for the Octavia II. I summarised it here:

 

Quite a few Superb owners have gone to 225/45 or 225/50 on the 18s. From what I've seen, 225/50 is very expensive compared to 225/40 or 225/45. 225/45 gets you an extra 11 mm nominal sidewall height, 225/50 gets you 22 mm. Both of these sizes are going to mess with your speedometer and odometer accuracy.

 

Another option on the Superb is 235/45 which gets you an extra 16 mm in sidewall height. IIRC this was a standard tyre size for the Octavia Scout so it might fit the vRS. The only problem I could see is the Scout's higher ride height putting the tyre in a different part of the wheelarch with more clearance.

 

Michelin Cross-Climates are only available in 225/40 or 235/45 for 18" wheels too from what I've been able to figure out.