Hey

 

so I just moved from 17" trifids to 18" themistos on a 2012 superb 4x4 combi and wanted to know if I need to recode anything?  (and yes I know they firm up the ride, but after an RS6 avant on coilovers, its still like a floaty dreamy cloud

 

I know from audis I've had in the past that some sat nav systems need to know the rolling diameter of your wheels, and I've had to do that with VCDS a few times (mostly RNS-E units), but I havent been able to find anything about colombus units or superbs specifically. 

 

also does the ECU pick up the tyre size via the TPMS now? or some other automagical method, or does it need to be coded in as well?

 

i've gone from 225/45/17 to 225/40/18 as a note, so 317/1993 (RD/Circumference) to 318.6/2002

 

cheers

 

t.

No, you should be fine without coding anything. The difference in circumference is tiny, so speedo should still be good too.

What have you done with your Trifids?

hey 

 

so they are out the back in a pile until I figure out what to do - they have a brand new (<500 miles) set of uniroyal rainsport 3s on them, so may keep them as winters, but ot depends on how a week of 18s go to be honest - just need to make sure that its ok on the roads that I drive etc. 

 

t.

 A brave move on Irish roads!! There may be 2/3% difference on Speedo but nothing too much.  I hope you don't do too much driving on the secondary roads, I see your location is Dublin so you may be fine!  The 18s do look great and corner better but I've become paranoid about kerbing them (already done one) and the potholes are a nightmare.  I don't notice any major deterioration in ride quality after having 17s before.

hey so an update for anyone interested

 

I've got about 2 weeks now on the 18's and frankly not noticing much of a difference to be honest. I'm running 2.3/2.2 bar pressures (front/back) and they seem similarly comfy to the old 17's on the car. 

 

Due to to a bit more out of town driving in the next few weeks so that may tell a different tale, but so far, its been ok!

Yeah there isn't a huge difference.  Coming from 16s to 18s would be a different story I reckon. Mind those potholes if your heading 'down the country'

I have to say, I'm finding the 18"s absolutely fine. I think when I need new tyres I'll put a set of 225 / 45 / 18 on just to give that tiny bit more protection ...

 

Cheers,

 

Rob