Carlston

I contacted Alcar and they said, "The rim 9021 is drilled with a 26mm ball bearing"...or at least that's the google translation of their German.

L06 is 5Q0411105GL, so it would make sense to fit these front springs. Kilen/Lesjofors lists these front springs as being correct for the Octavia MK3 2.0TDI 105kW/143PS estate with standard ride height (without listing whether it's for manual or automatic transmission). Bilstein 37-293215 are sold to replace five different OEM part numbers including 5Q0411105GK and 5Q0411105GL so these front springs will be able to support the weight of the cars that these springs are normally fitted to. Bilstein 36-292776 rear springs are sold to replace both 5Q0511121AF and 5Q0511121AG, so will be able to support the weight of the car that these are normally fitted to. Bilstein 36-292936 rear springs are sold to replace 5Q0511121AA, 5Q0511121AB, and 5Q0511121AC rear springs. They are far too soft for your car and won't support the weight of the estate/combi/wagon.

Alcar 9021 are 17" Kodiaq MK1 steel rims, ie. 6.5Jx17 ET38 5/112 57.1 so use the standard wheel bolts with OEM part number WHT001812. These have a ball-shaped seat and are correct for both the Skoda alloy and steel rims. 10 WHT001812 Wheel bolt M14x1.5x27 20 https://www.lllparts.co.uk/catalogs/skoda/CZ/KOD/804/6/601/601010 EIBACH Pro-Spacer S1-6-14-50-27-17 Wheel Bolt (M14x1.5x27) (ball-shaped seat) https://www.autodoc.co.uk/car-parts/oem/wht001812?supplier%5B%5D=112

Octavia MK3 2.0TDI estate 105kW/143PS (FWD Front Wheel Drive) (rigid rear axle) Standard ride height front springs (manual transmission) 5Q0411105GK Standard ride height front springs (automatic transmission) 5Q0411105GL Standard ride height rear springs (without towbar) 5Q0511121AF Standard ride height rear springs (with towbar) 5Q0511121AG When changing from increased ride height springs to standard ride height springs, change the front shock absorber buffers to ones that have a 70mm height. The increased ride height front shock absorber buffers are often 90mm in height, so this change will free up an additional 20mm in front suspension travel. The 70mm buffers are what the factory Octavia MK3 cars use with standard ride height suspension. Octavia MK3 2.0TDI estate 105kW/143PS (50mm front shock absorber struts) 70mm front shock absorber buffer for standard ride height 1K0412303B

The Octavia MK2 parts catalogue shows that build codes 2UA/L07 is a 1K0411105AQ front spring marked with either 1 violet, 1 orange, 1 blue or 1 grey, 4 blue. So the colour that looks like pink is actually violet...at least according to the Octavia MK2 parts catalogue. kilen 25061 matches 1K0411105AQ and is available for under £30 each on ebay.

Narrower tyres would help lighten the steering especially if the car is currently fitted with the wide 235/45R18 or 235/40R19. The contact patch of 215/60R16 is slightly narrower than 215/55R17, due to the higher aspect ratio. However, 205/65R16 would be even better than 215/60R16. 205/65R16 would fit on the standard 6.5Jx16 ET41 rims. 205/65R16 has the same 95(690kg) load index as 215/60R16, so there's no problem with the tyre supporting the full axle loads of the car. Michelin Primacy 5 205/65R16 95W (Euro label C A 70dB) (Example tyre, not a recommendation) https://www.mytyres.co.uk/rshop/tyre/Michelin/Primacy-5/205-65-R16-95W-EV-Suitable/D-139307

Bilstein B4 22-183712 and Bilstein B6 35-250852 are correct because they are listed against the 1K0413031BL OEM part number. The Yeti also uses the 1K0413031BL OEM part number on some models, and the Octavia MK2 with increased ride height is using Yeti suspension...hence when the Bilstein listings list the Yeti, that is actually reassuring. When looking for suitable aftermarket shock absorbers it's best to use the OEM part number to decide if it will fit rather than descriptions such as what vehicle it fits...because those descriptions are often incomplete and/or misleading. The listing for Sachs 560 287 front shock absorbers lists thirty two OEM part numbers, at least one of which is a lowered ride height front shock absorber (1K0413031BJ). Therefore, it looks like either of the above mentioned Bilsteins would be a better match. Notice below how similar the entries are in the Octavia MK2 and Yeti parts catalogues for the 1K0413031BL front shock absorbers. The L60, L61, and L66 front springs for the Octavia MK2 with increased ride height (aka heavy duty suspension) are the same as the L60, L61, and L66 front springs for the Yeti. Octavia MK2 parts catalogue 8 1K0413031BL Front shock absorber for models with heavy duty suspension 2 PR:G02+2UB+ L60,L61,L66 Yeti parts catalogue 8 1K0413031BL Front shock absorber PR:G02+L60, L61,L66,L67

Bilstein B4 22-183712 and Bilstein B6 35-250852 front shock absorbers are both sold to replace OEM part number 1K0413031BL. These are both listed against fifteen different OEM part numbers. KYB 334834 is listed against fifty eight different OEM part numbers, so they might not be a close match to 1K0413031BL. As well as the Octavia MK2 with increased ride height, 1K0413031BL front shock absorbers are also used on the Yeti.

In general, the higher the sidewall the more comfortable the ride...so in general, the ride is softest on the 16" rims and hardest on the 19" rims. If you like big wheels, one non-standard option is 245/45R18 8Jx18 ET45. Steel rims from the Skoda Enyaq are available in this specification...which are going to be considerably cheaper than alloys. The matching wheel trims are quite smart...as shown in the photo below. Karoq front wheel drive wheel sizes 215/60R16 6Jx16 ET43 215/55R17 7Jx17 ET45 215/50R18 7Jx18 ET45 225/40R19 8Jx19 ET45 Alcar 9383 8Jx18 ET45 5/112 57.1 steel rim 13.26kg (from Skoda Enyaq) https://www.mytyres.co.uk/rims/details?vehicleId=1313955427855111280&rimCode=ALCAR9383 Wheel trims to fit 8Jx18 ET45 steel rims 5LA601147 Z31 (from Skoda Enyaq) https://www.skoda-parts.com/spare-part/5la601147z31-wheel-cover-18-skoda-48660.html

The Superb MK3 parts catalogue lists ten standard ride height rear springs for the FWD (Front Wheel Drive) car, as shown below. The springs are listed in order from softest to stiffest. Standard ride height rear springs (Superb MK3 FWD) 3Q0511115AH (Length 363mm, Wire diameter 11.25mm) 3Q0511115AJ (Length 361mm, Wire diameter 11.75mm) 3Q0511115AK (Length 364mm, Wire diameter 12.25mm) 3Q0511115AL (Length 359mm, Wire diameter 12.5mm) 3Q0511115M (Length 360mm, Wire diameter 12.75mm) 3Q0511115N (Length 361mm, Wire diameter 13.25mm) 3Q0511115P (Length 361mm, Wire diameter 13.5mm) 3Q0511115Q 3Q0511115R (Not available aftermarket) 3Q0511115BC (Not available aftermarket) Kilen 65125 (matches 3Q0511115AL) (£55.49 for two, on ebay) https://www.autodoc.co.uk/car-parts/oem/3q0511115al?supplier%5B%5D=246 https://www.ebay.co.uk/itm/352663645780 Kilen 65126 (matches 3Q0511115M) (£55.49 for two, on ebay) https://www.autodoc.co.uk/car-parts/oem/3q0511115m?supplier%5B%5D=246 https://www.ebay.co.uk/itm/352663645884 Bilstein 36-301942 (matches 3Q0511115N) https://www.autodoc.co.uk/car-parts/oem/3q0511115n?supplier%5B%5D=16 According to the Kilen online spring catalogue the Superb MK3 1.5TSI estate FWD with standard ride height has the third in the list, ie. 3Q0511115AK. However, according to the gknautomotive online spring catalogue the Superb MK3 1.5TSI estate FWD with standard ride height has the fourth in the list, ie. 3Q0511115AL. One way to find out what the factory fitted rear springs are is to open an account on "skoda parts com" and put the car in their online garage with its VIN number. Then when the rear springs are searched for, only the factory fitted ones will be shown...which enables the original OEM part number to be found.

Carrying a full load in the car doesn't increase the tyre pressures...even on a temporary basis while the load is being carried. For example, the spare tyre will have the same tyre pressure whether it's off the car or fitted to the car carrying the weight of the car. If the car's tyres are inflated when they are hot, simply add 3psi to the normal pressures and check again (adjusting the pressures if necessary) in the evening or after dark when the sun isn't heating the air in the tyres. Air expands by about 10% when the temperature increases from 20 degrees Centigrade to 50 degrees Centigrade...so you might find that the tyre pressures increases by about 10% when they are measured at 50C compared to when they are measured at 20C...or about 3psi.

So the pattern appears to be... Octavia MK3 uses 50mm struts (and 80mm wheel bearings) with 276x25mm and 288x25mm front brake discs. Octavia MK3 uses 55mm struts (and 85mm wheel bearings) with 312x25mm and 340x30mm front brake discs.

The Octavia MK3 uses two different front strut diameters...50mm and 55mm The diameter of the front struts depends on what size front brake discs are fitted. The smallest 276x24mm front brake discs use the 50mm struts, whereas the other front brake discs (ie. 288x25mm, 312x25mm, 340x30mm) use the 55mm struts.

To find the OEM part numbers of parts like the shock absorbers, the website "skoda parts com" can be used. This Czech website lets you add one Skoda to your online garage free of charge, and then parts that you search for on this website can be matched against the car's VIN number. Once you have the car's OEM part numbers, it's easier to search for aftermarket parts elsewhere. It's best to search for aftermarket parts using the car's OEM part numbers, rather than simply relying on a description of the car's model, etc.

Some aftermarket 17" alloy rims won't clear the 340x30mm front brake discs, but most 17" VAG rims will. The owner's manual doesn't list anything bigger than 17" rims for use with snow chains...so if 18" rims really were needed, Octavia MK4 owners would have to park their car on the drive and take the train everytime it snowed.