I'm looking to change my shocks and springs to the trusty Eiback / Koni FSD combination. But to do this I need to find out whether I need a 50 or 55mm diameter strut. I'll cheerfully admit to being a technical luddite so I've got no idea what or where I need to measure to find this out. So far two Skoda garages have failed to help, the first trying through my chassis number and having no dimension info on their system, the second trying off the part number on the front strut and not recognising the number.

(As an aside this helps with my long running dispute with Skoda about whether the wrong suspension's been fitted to my car in the first place given the rock-hard ride - see http://briskoda.net/forums/topic/200946-octavia-estate-hardcrashy-suspension/ )

Back on topic, the car's a 2010MY Octavia 1.8TSi L&K Estate, standard suspension, so would anyone out there be able to tell me whether I need the 50 or 55mm struts or tell me where to check to find out?

Many thanks!

Having been in touch with a couple of dealers, the part number I'm supposed to have for the front strut is 1T0 413 031HN, which is strangely different from the 1T0 412 015MG that is fitted at present. I can feel another conversation with Skoda customer service coming on...

Its quite common for a part number to be superceded by another - it does not necessarily mean that the part is to a different specification.

I know on the VRS the estates have the 55mm struts and the hatch have the 50mm. I would have thought with yours being an estate you would also need the 55mm.

Sadly you will always have to measure the front strut diameter. There are even VRS octavias with 50mm struts.

Turn the wheel completely to one side and look at the front suspension, you will see the front dampers.

Just measure the diameter where the damper goes into the part that holds the wheel (dont what you call that).

I know on the VRS the estates have the 55mm struts and the hatch have the 50mm. I would have thought with yours being an estate you would also need the 55mm.

We're talking suspension struts here

What you've said about the hatch above is incorrect. The models known to have 50mm struts are the 1.9 PD105 and lower powered petrol variants.

PD140 models are 55mm, as is the vRS (regardless of engine type). I would say that the 1.8TSi would be 55mm too, but I reckon the only way you're going to be 100% is if you physically measure them. I had the same issue when I tried to ascertain which size my PD140 had, and the dealers were of no assistance.

We have VRSs in the german board with 50mm struts, although the VRS should have 55mm.

Oh great - makes things even more straightforward hey!

Did have a bit of info on how you might be able to tell, but think it did involve knowing what you already had fitted, in terms of part number. And to tell that you need to access the current strut really. And if you're doing that you might as well measure it

Thanks for the replies everyone! I have been outside and grovelled down beside the car and it turns out I have 55mm struts.

Thanks for the replies everyone! I have been outside and grovelled down beside the car and it turns out I have 55mm struts.

Good stuff - that was my hunch, but much happier now that you've checked for yourself