Hello, okay so i got a 2013 octavia combi and it has 2.0l diesel engine(150 hp) and i did not buy this car new, so im not sure about the wheel size. when i bought the car, it had 18" wheels and the tire size was 235/40R18 and the car looked beautiful. BUT i live in a small town in Iceland, and the roads are horrible almost like driving on gravel road, and we also have a lot of gravel roads in Iceland and i am going to be traveling alot around the country this summer. SO i swapped the wheels for the oem 16" with 205/55R16 tires. But instantly i saw the car was lower, and i also find it lower than other skodas i see, and i think the speedomeeter is not correct, i use speedometer app in my phone and when my car says 100km/h my phone reads 92km/h. I used a tire calculator and it seems the new tire is 1.3 cm lower than the 18", so my question is, was the speedometer wrong to begin with with the 18" or is my car different from 98% of octavias in iceland who has 205/55R16 ? I called the dealer and gave him the licence plate number of my car and he said it was ordered from the factory on 18" so do you think the speedometer is set for that tire size? and is it possible that something about the suspension is different because i find it lower than other cars i see? If that is the case i think i have to put 205/60R16 tires on the rims so the readings are correct but like i said the dealer had no idea and neither do i so i ask you guys if you have any idea:)

 

Sorry for the bad english! i hope you understand this.

I think most of the versions have tyres that are 205 or 225 wide - so 225/40/18 would be standard. For 16" the 205/55/16 is definitely correct (unless you have the Scout).

 

You can check your specific model and what sizes are allowed here: http://www.skoda-auto.de/sitecollectiondocuments/serienreifen_skoda_2014_07_1.pdf

Yep, 225/40R18 - I've had 2 now with 18" as standard, and in both the spare has been 205/55R16 as it is pretty much the same radius.

 

Sounds like a previous owner fitted some wider tyres with a bit more sidewall ........

The tyre you have now is odd for Octavia.

205/55R16, 225/45R17, 225/40R18 and 225/35R19 are all tyre dimensions for a "normal" Octavia. All these has a circumference which is approximately the same, and the speedometer will show about correct speed. That is, all speedometers are set to show a little less than actual speed. 7-10% is quite normal. If you fit tyres like 205/60R16 on 16 inch rims (like on Scouts), you will get a more accurate speedometer reading. In addition you will have slightly higher stance because of the increased tyre side wall height. The narrower tyres are more suitable for gravel roads as well.

I agree with the other about the tyre sizes.

The 18" are not the "standard" size. 16" are correct.

 

Maybe ask the dealer to check that the previous owner didn't also lower the suspension in assosiation with the new alloys.

Its quite common (see several threads on this board) to fit new springs & parts are readily available.

I'm thinking to change the dreadful Conti sportcontact2 set I have for summer with something quieter and smoother.

All in all I would also like to increase the profile (even maybe reduce the width to 215) to get some comfort improvement.

Current size: 225/40 R18 92Y

Options I consider seeking better comfort:

- higher profile 225/45 is just +3% circumference / diameter: http://www.willtheyfit.com/index.php?width=225&aspect=40&diameter=18&wheelwidth=7.5&offset=51&width2=225&aspect2=45&diameter2=18&wheelwidth2=7.5&offset2=51&Submit=Calculate#content

- narrower/higher profile +2%: http://www.willtheyfit.com/index.php?width=225&aspect=40&diameter=18&wheelwidth=7.5&offset=51&width2=215&aspect2=45&diameter2=18&wheelwidth2=7.5&offset2=51&Submit=Calculate#content; might be more risk for the 7,5" rim, so I'm not exactly convinced;

- lower speed index, as 240km/h "V" would be more than enough (W-270, Y-300)

- lower load index - I guess 92 (630kg) is way too high

 

Any thoughts on above? Did anyone try similar approach?

Remember that all speedos read high, anywhere between 2 and 10%. My R will show 54mph when my GPS readout is 50mph, the difference varies at different speeds.

 

As long as you have a rough idea of the difference why worry?

The "it isn't type approved so will invalidate your insurance and warranty" brigade will no doubt be along shortly .......

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Our Octy just got new 205/60 R16 96W summer tires (Goodyear EfficientGrip Performance) alter 205/60 R16 96T winter tires (Goodyear UltraGrip Ice2). Factory size was 205/55 R16 91V (Michelin Energy Saver+), the current ones are 3,2 % taller and now the speedometer is quite near the real speed.

Not any problems with higher profile and no problems with higher Load index. Enough smooth and silent ride on the poor rough asphalt roads.

Yes, we have 15 mm higher Rough Road Package and there is still lot room in the wheelwell.

Edited 29 April, 201610 yr by Grumpy Finn