Carlston

Nominally, a 235 tyre is 10mm wider than a 225 tyre. However, the actual inflated width of a tyre always depends on what rim width it is fitted to. As you can see in the chart below, a 235/40R19 fitted to an 8.5" rim width is actually only 5mm wider than a 225/40R19 fitted to an 8.5" rim width. Notice also, that a 235/40R19 fitted to an 8.5" rim width is actually 11mm wider than a 225/40R19 fitted to an 8" rim width...and a 235/40R19 fitted to an 8.5" rim width is actually 17mm wider than a 225/40R19 fitted to a 7.5" rim width. Actual inflated width of tyre (measured sidewall to sidewall, at the widest point) 225/40R19 fitted to 7.5" rim width 224mm 225/40R19 fitted to 8" rim width 230mm 225/40R19 fitted to 8.5" rim width 236mm 235/40R19 fitted to 8.5" rim width 241mm

The eXtra Load index of 235/35R20 is only 92(630kg). The Superb MK3 normally uses tyres with at least a 94(670kg) load index. It might be worth checking to make sure that the maximum rear axle load isn't more than 1260kg...otherwise using 92(630kg) tyres would be illegal.

This is listed in the Superb MK2 section, so is the car a Superb MK2 or an Octavia MK2? The outside diameter of 235/50R18 is far too big for either the Superb MK2 or the Octavia MK2, as shown in the chart below. Up to 1.5% bigger outside diameter than standard is generally considered acceptable, so 8.6% bigger than standard is far too big an increase in outside diameter. Outside diameter of tyre 225/40R18 637.2mm 235/50R18 692.2mm (8.6% bigger outside diameter compared to 225/40R18)

Build code L19 means that the car has 5Q0411105HF front springs. KYB lists their KYB RA4127 front spring to replace 5Q0411105HF, although KYB also lists three other OEM part numbers against this spring so KYB RA4127 may not be an exact match to 5Q0411105HF. However, 5Q0411105HF is listed as being 33mm shorter than the standard ride height front spring 5Q0411105GN that KYB lists for the standard ride height car (Superb MK3 2.0TDI 190HP 4x4). So that 15mm nominal drop could actually be a lot more, eg. 33mm. Bear in mind that both the 5Q0411105HF and 5Q0411105GN front springs have a wire diameter of 12.5mm and about 4.6 coil turns, so it's reasonable to assume that the 33mm difference in their uncompressed lengths will result in a 33mm drop in ride height. Bilstein make their B8 for the nominally 15mm lower ride height cars. Bilstein want to sell a lot of their B6 shock absorbers, so they aren't primarily aimed at the Eibach 30mm-40mm drop springs, etc. KYB RA4127 (sold to replace 5Q0411105HF and three other front springs) Length 285mm Wire diameter 12.5mm Number of coil turns 4.6 https://www.autodoc.co.uk/kyb/12818916#coil-spring KYB RA1491 (matches 5Q0411105GN) Length 318mm Wire diameter 12.5mm Number of coil turns 4.6 https://www.autodoc.co.uk/kyb/18427435#coil-spring

The only authority on what tyre sizes can be fitted to what rim widths is ETRTO (European Tyre and Rim Technical Organisation). Even the car manufacturers including VAG aren't allowed to go outside ETRTO's recommendations. As you can see in the chart below, 215/40 and 215/35 can both be fitted to an 8.5" rim width. What you can fit to a particular rim width doesn't just depends on the tyre's width but also on the tyre's aspect ratio . For example, a 225/50 can't be fitted to a 8.5" rim width, but a 225/45, 225/40, and 225/35 can. VAG will rarely fit a tyre to the maximum rim width...and for good reasons. ETRTO approved rim widths for passenger car tyres 50 Series 215/50 6.0-7.0-7.5 225/50 6.0-7.0-8.0 235/50 6.5-7.5-8.5 245/50 7.0-7.5-8.5 45 Series 215/45 7.0-7.0-8.0 225/45 7.0-7.5-8.5 235/45 7.5-8.0-9.0 245/45 7.5-8.0-9.0 40 Series 215/40 7.0-7.5-8.5 225/40 7.5-8.0-9.0 235/40 8.0-8.5-9.5 245/40 8.0-8.5-9.5 35 Series 215/35 7.0-7.5-8.5 225/35 7.5-8.0-9.0 235/35 8.0-8.5-9.5 245/35 8.0-8.5-9.5

225/35R19 is an Octavia MK3 tyre size, whereas 225/40R19 is an Octavia MK4 tyre size. As you can see in the chart below, the outside diameter of 225/35R19 is too small for the Octavia MK4. Outside diameter of tyre 225/40R19 662.6mm 225/35R19 640.1mm (3.4% smaller outside diameter compared to 225/40R19)

The spare wheel on the Octavia MK2 VRS needs to be at least 16" to clear the calipers on the front 312x25mm brake discs, so I expect you have a 205/55R16 6.5Jx16 ET50 5/112 57.1 steel spare wheel. If the Superb MK3 is not a 272HP/280HP 4x4 car, then the 205/55R16 from the Octavia MK2 can be used as a spare because Skoda does sometimes supply a similar (just 4mm different offset, ie. ET50 vs ET46) 205/55R16 6.5Jx16 ET46 5/112 57.1 (from the Octavia MK3) as a spare for the Superb MK3. The Superb MK3 272HP/280HP 4x4 has 340x30mm front brake discs and 310x22mm rear brake discs, so the spare wheel needs to be at least 17" to clear the brake calipers on both the front and the rear of this car. So an 18" spare saver is actually 1" bigger than is actually required to clear the brake calipers.

As you can see in the chart below, 125/70R18 has a much smaller outside diameter than the standard 17" tyre size on the Superb MK3. However, Skoda normally supply a 205/55R16 fitted to a 6.5x16 ET46 5/112 57.1 steel rim (from the Octavia MK3) as a spare wheel for the front wheel drive Superb MK3. Like the 125/70R18, the 205/55R16 tyre has an outside diameter that is much smaller than the standard Superb MK3 tyre sizes. Perhaps look at using a 215/60R15 Karoq wheel, ie. 215/60R16 fitted to a 6Jx16 ET43 5/112 57.1 steel rim. This should fit in the spare wheel well of a front wheel drive Superb MK3. I expect the 4x4 version would have less room and therefore need a spare saver...although I would look at a 135/80R18 fitted to the standard 3.5Jx18 ET25.5 5/112 57.1 space saver steel rim, rather than the rather small 125/70R18. Note that a standard Superb MK3 wheel such as 215/60R16 fitted to the standard 6.5Jx16 ET41 5/112 57.1 rim is about 6mm too wide to fit in the spare wheel well without raising the carpet. The widest inflated tyre that will fit in the spare wheel well of the Superb MK3 is 215mm. Unfortunately, the standard 215/60R16 fitted to its 6.5J rim is about 6mm too wide...at about 221mm...as shown in the chart below. Outside diameter of tyre 215/55R17 668.3mm 125/70R18 632.2mm (5.4% smaller outside diameter compared to 215/55R17) Actual width of inflated tyre (measured from sidewall to sidewall at the widest point) 215/60R16 fitted to 6.5J rim 221mm 215/60R16 fitted to 6J rim 215mm Alcar 6665 6Jx16 ET43 5/112 57.1 steel rim fitted with Continental UltraContact 215/60R16 95V https://www.mytyres.co.uk/cw/bundle?vehicle_ids=1302234084152546416&wheelId=SKWi-6665--D-126062&wheelIdWithTpms=&season=so&rimType=steel

Left rear brake caliper 310x22mm 1KW 5F0615423 Right rear brake caliper 310x22mm 1KW 5F0615424 Carrier for left rear brake caliper 310x22mm 1KW 8U0615425A Carrier for right rear brake caliper 310x22mm 1KW 8U0615426A https://www.lllparts.co.uk/catalogs/skoda/CZ/OCT/805/6/615/615065

The Polo MK6 parts catalogue lists 2Q0407255L, 2Q0407256L, 2Q0407255AE, and 2Q0407256AE...with the AE version being a newer version of the older L version. Cars manufactured after 25/05/2020 used the newer AE version instead of the older L version. It seems likely that they are interchangeable. Polo MK6 parts catalogue https://www.lllparts.co.uk/catalogs/vw/RDW/PO/837/4/407/407000

If changing the rear springs from standard ride height to lowered ride height, you will also probably want to change the rear shock absorber buffers from 127mm to 112mm. This will provide an extra 15mm of suspension travel compared to if you don't change them. With the non-DCC car, it looks like 5Q0511357J would be suitable...although do confirm this with the person who is going to fit the Bilstein B6/B8 rear shock absorbers. 112mm rear shock absorber buffers 5Q0511357J (for lowered rear springs, non-DCC) https://www.autodoc.co.uk/car-parts/oem/5q0511357j?supplier%5B%5D=101

16" rims will clear the front brake calipers on 312x25mm front brake discs. All of the front shock absorbers on the Scala and Polo MK6 (and Audi A1 based on the Polo MK6) use the same diameter struts. Don't use Polo MK6 GTI front wheel bearings because those require Polo MK6 GTI drive shafts which are longer than the other Polo models. These 312x25mm front and 272x10mm rear brakes are both TRW brake systems. The 256x22mm front brakes use a 22.2mm master cylinder bore, whereas the 276x24mm and 312x25mm front brakes use a 23.8mm master cylinder bore. So you might want to consider changing the master cylinder if increasing the size of the 256x22mm front brakes. However, it looks like the servo is also different...and there might also be other differences.

Eibach R16554 is sold to replace 5Q0511115Q and 5Q0511115R, so probably matches 5Q0511115R. 5Q0511115R is just one down in the hierarchy compared to 5Q0511115S (eg. Eibach R19953). A lot could depend on how much weight you carry over the rear axle. If the Eibach R16554 did prove to be too soft, then the Eibach R16554 could be changed to the Eibach R19953. Whatever you fit, it's worth taking careful measurements of the new front and rear springs before fitting them. Then if the front or back proves to be too high or too low, this information should help find suitable alternative springs. Measurements I would want are the uncompressed length, the coil spring diameter, and the number of coil turns...maybe even the weight in kilograms.

If you don't want to go with my first suggestion, ie. 5Q0411105HD front springs and 5Q0511115AA rear springs...perhaps try 5Q0411105HC front springs and 5Q0511115S rear springs. Compared to the 5Q0411105HD front springs and 5Q0511115AA rear springs, they probably would drop the ride height a little more. Eibach R19200 front springs (sold to replace 5 springs including 5Q0411105HC, so might not be an exact match...although specification seems ok) https://www.autodoc.co.uk/eibach/17876013 Eibach R19953 rear springs (sold to replace 5Q0511115S and no other springs, so should be an exact match) https://www.autodoc.co.uk/eibach/18259209?search=EIBACH+Coil+spring+%28R19953%29

Kilen lists the Octavia MK3 2.0TDI 4x4 with automatic DSG gearbox as having 5Q0411105HF front springs. 5Q0411105HD are softer than 5Q0411105HF. The alternaive to 5Q0411105HD is 5Q0411105HC, but that spring is softer than 5Q0411105GL. Eibach R16554 are about 10% softer than your current standard ride height rear springs, which I suspect are 5Q0511115H. The actual lengths of springs will often turn out to be slightly different from what the manufacturer claims. I once purchased two springs with the same OEM part number but they weren't from the same production batch, and I noticed that their lengths were about 10mm different. Fortunately, the parts guy gave me an immediate refund and he ordered in a pair of springs that were from the same batch. Bear in mind that stiffer springs compress less (and softer springs compress more) under the weight of the car, so that too affects the unladen ride height...not just the uncompressed lengths of the springs.

As you can see below, dtintecno claims that the 1.2TSI 90PS/110PS engines remap to the same power/torque. dtintecno claims 130PS/215Nm for a remap on the 1.2TSI 90PS and 110PS engines. dtintecno claims 145PS/250Nm for a remap on the 1.4TSI 122PS engine. dtintecno claims 155PS/270Nm for a remap on the 1.4TSI 125PS engine. 140PS from just a remap for the 1.2TSI engine sounds like an exaggeration. This isn't a recommendation for dtintecno, but their claims seem reasonable...unlike some other remappers.

One blue dot and one brown dot is 5Q0411105GL, so Kilen got it right in their online spring catalogue.

Bilstein B6 are for standard ride height springs. Bilstein B8 are for lowered ride height springs. So go for Bilstein B8 with the lowered ride height springs, unless you are planning to change back to standard ride height springs at some point in the future. You won't need the 55mm buffers with the Bilstein B6/B8 because the buffers are built into these high quality shock absorbers. Bilstein B6/B8 without DCC have a superior mono-tube design, whereas Bilstein B6 with DCC have an inferior twin-tube design. So that's a big advantage in not having DCC.

These lowered ride height springs should be suitable for the Octavia MK3 1.8TSI 180PS estate 4x4 DSG. They should be similar to what Skoda would have fitted if the car had left the factory with lowered ride height springs. Remember to change the front buffers if changing from standard ride height springs to lowered ride height springs. 55mm buffers with OEM part number 1K0412303F should fit if you don't have electronically adjustable shock absorbers. The standard ride height front springs use buffers that have a length of about 70mm, so changing to these 55mm buffers will provide an extra 15mm of front suspension travel compared to using the old 70mm buffers. Lowered ride height front springs 5Q0411105HD Bilstein 37-293192 Kilen 23133 (same as Lesjofors 4085734) Lesjofors 4085734 (same as Kilen 23133) https://www.autodoc.co.uk/car-parts/oem/5q0411105hd?supplier%5B%5D=246&supplier%5B%5D=85&supplier%5B%5D=253&supplier%5B%5D=16 Lowered ride height rear springs 5Q0511115AA Bilstein 36-301904 Kilen 63145 (same as Lesjofors 4285746) Lesjofors 4285746 (same as Kilen 63145) https://www.autodoc.co.uk/car-parts/oem/5q0511115aa?supplier%5B%5D=246&supplier%5B%5D=16&supplier%5B%5D=253&supplier%5B%5D=85 55mm buffers for front shock absorbers 1K0412303F (not for electronically adjustable shock absorbers) https://www.autodoc.co.uk/car-parts/oem/1k0412303f?supplier%5B%5D=10249

These details are extracted from the Kilen online spring catalogue. Do you have electronically controlled shock absorbers? Have you got a manual or automatic DSG gearbox? This makes a difference to the front springs because the automatic gearbox is heavier than the manual gearbox so the front springs are normally slightly stiffer to compensate for this. Do you want the lowered springs to be the same stiffness as the standard springs, about 5% stiffer, or about 10% stiffer. If you often fully load the car or don't mind a harder ride you will probably want 10% stiffer springs. However, if you normally don't carry much weight in the car and want to keep the ride comfort of the standard ride height springs it's possible to fit lowered ride height springs that have about the same stiffness as the standard ride height springs. For example, the lowered ride height springs on the Superb MK3 are about the same stiffness as the standard ride height springs. It could be useful if you could find out what the OEM part numbers are for the front and rear springs, ie. what the car left the factory with. It looks to me like Kilen has made a mistake with your car, as they are listing 5Q0511115G rear springs, which they also list for the front wheel drive car. This can't be right because the 4x4 uses stiffer rear springs than the equivalent front wheel drive car because of the extra weight over the rear axle of the 4x4 system. Octavia MK3 hatchback 1.8TSI 180PS front wheel drive DSG Front springs (standard ride height) 5Q0411105GL Front springs (lowered ride height) 5Q0411105HC Rear springs (standard ride height) 5Q0511115E Rear springs (lowered ride height) 5Q0511115Q Octavia MK3 hatchback 2.0TDI 184PS front wheel drive manual gearbox Front springs (lowered ride height) 5Q0411105HD Rear springs (lowered ride height) 5Q0511115Q Octavia MK3 hatchback 2.0TDI 184PS front wheel drive DSG Front springs (lowered ride height) 5Q0411105HF Rear springs (lowered ride height) 5Q0511115Q Octavia MK3 hatchback 2.0TDI 184PS 4x4 DSG Front springs (lowered ride height) 5Q0411105HF Rear springs (lowered ride height) 5Q0511115S Octavia MK3 estate 1.8TSI 180PS front wheel drive DSG Front springs (standard ride height) 5Q0411105GL Rear springs (standard ride height) 5Q0511115G Octavia MK3 estate 1.8TSI 180PS 4x4 DSG Front springs (standard ride height) 5Q0411105GL Rear springs (standard ride height) 5Q0511115G (Kilen might have made a mistake with this spring because it should be stiffer than the equivalent front wheel drive car) Octavia MK3 estate 2.0TDI 184PS 4x4 DSG Front springs (lowered ride height) 5Q0411105HF Rear springs (lowered ride height) 5Q0511115AA

See Doofy's post dated 15 April, 2024 in the below thread. Doofy says that 205/60R16 fitted to a 6Jx16 ET35 5/100 57.1 will fit in the Kamiq's wheel well. However, as the 205/55R17 and 215/45R18 options aren't much wider...maybe they will also fit...but they are a few millimetres wider than the 205/60R16 option.

The below foam and jack kit for the Kamiq includes everything except for the actual spare wheel, which can be purchased separately. On the "skoda eshop cz" website, it's listed at 1,089CZK (about £37.25). This can be ordered from any VAG parts department by quoting OEM part number 658093860A. From the listing, it looks like the official spare wheel for this foam and jack kit is 195/60R16 fitted to a 6Jx16 ET35 5/100 57.1 steel rim. Perhaps purchase the foam and jack kit first, and see if one of the 215/45R18 7Jx18 ET39 5/100 57.1 alloy rims will fit. You might find that it will only fit without lifting the carpet if all the air is let out, ie. removing the air valve so that the tyre's sidewalls go floppy. Foam and jack kit for Kamiq 658093860A https://eshop.skoda-auto.cz/cs_CZ/sada-pro-vymenu-rezervniho-kola-16/p/658093860A Notice in the chart below, that the 215/45R18 fitted to a 7" rim width is actually narrower (by 1mm) than a 205/55R17 fitted to a 6.5" rim width. Actual inflated width of tyre (measured from sidewall to sidewall at the widest point) 195/60R16 fitted to 6" rim width 201mm 205/60R16 fitted to 6" rim width 209mm 205/55R17 fitted to 6.5" rim width 214mm 215/45R18 fitted to 7" rim width 213mm Outside diameter of tyre 195/60R16 640.4mm 205/60R16 652.4mm 205/55R17 657.3mm 215/45R18 650.7mm Mytyres can supply a 6Jx16 ET35 5/100 57.1 steel rim. Alcar 6664 6Jx16 ET35 5/100 57.1 steel rim https://www.mytyres.co.uk/rims/details?vehicleId=1077003525243802724&rimCode=ALCAR6664

7Jx17 ET45 5/112 57.1 alloy rims (from Audi Q2) 81A601025A 8Z8 81A601025B 8Z8 81A601025C 8Z8 81A601025D 8Z8 81A601025AJ 8Z8 81A601025AK 8Z8 https://www.lllparts.co.uk/catalogs/audi/RDW/AQ2/803/6/601/601070 7Jx17 ET45 5/112 57.1 alloy rims (from VW T-Roc) 2GA601025B ZD8 2GA601025N FZZ 2GA601025P XM4 2GA601025K XZ6 2GA601025A 8Z8 2GA601025J DM9 2GA601025R FZZ 2GA601025AF FZZ 2GA601025AG FZZ 2GA601025AC 8Z8 2GA601025AR FZZ 2GA601025M 8Z8 https://www.lllparts.co.uk/catalogs/vw/RDW/TRO/813/6/601/601060 7Jx17 ET45 5/112 57.1 alloy rims (from Karoq) 57A601025C 8Z8 57A601025F 8Z8 57A601025H FL8 57A601025AB 57A601025AR 57A601025B 57A601025AA 57A601025AT https://www.lllparts.co.uk/catalogs/skoda/CZ/KAR/834/6/601/601065 7Jx17 ET45 5/112 57.1 alloy rims (from Yeti) 5L0601025 7ZS 5L0601025N HA7 5L0601025A 7ZS 5L0601025H 7ZS 5L0601025B 7ZS 5L0601025F FL8 5L0601025G 8Z8 5L0601025L 8Z8 5L0601025Q FL8 5L0601025S FL8 5L0601025K 8Z8 5L0601025AC HA7 5L0601025AB FL8 https://www.lllparts.co.uk/catalogs/skoda/CZ/YET/666/6/601/601070

The outside diameter of 235/35R19 is too small for the Octavia MK4, as shown in the chart below. 235/35R19 has an outside radius 7.75mm less than 225/40R19, so that's how much bigger the gap will be between the top of the tyre and the wheelarch. This will result in an Octavia MK4 with sports/lowered suspension starting to look like it has standard ride height...or at least not as lowered as it looked on the standard 225/40R19 tyre size. Perhaps look at 235/40R19, although the minimum rim width that ETRTO list for this tyre size is 8". However, ETRTO also list the same 8" minimum rim width for the wider and lower sidewall height 245/35R19...so some would consider the fitment of a 235/40R19 to a 7.5" rim width as not much different to fitting a 245/35R19 to an 8" rim width. Outside diameter of tyre 225/40R19 662.6mm 235/35R19 647.1mm (2.3% smaller outside diameter compared to 225/40R19)

The specification of that steel rim is 6Jx14 ET38 5/100 57.1 which is different from 5Jx14 ET35 5/100 57.1, ie. 1" difference in the rim width and 3mm difference in the offset...plus the appearance is different...which you can see from the photos below. Alcar 5210 5Jx14 ET35 5/100 57.1 steel rim (6.78kg) (from Fabia MK1/MK2/MK3, Roomster, Rapid) https://www.mytyres.co.uk/rims/details?vehicleId=180852620338926692&rimCode=ALCAR5210 Alcar 3055 5Jx14 ET38 5/100 57.1 steel rim (6.85kg) (from Fabia MK4) https://www.mytyres.co.uk/rims/details?vehicleId=1351328927595312228&rimCode=ALCAR3055 Alcar 7250 6Jx14 ET37 5/100 57.1 steel rim (7.23kg) (from Fabia MK2, Roomster) https://www.mytyres.co.uk/rims/details?vehicleId=183698156431610980&rimCode=ALCAR7250 Alcar 7600 6Jx14 ET38 5/100 57.1 steel rim (7.70kg) (from Golf MK4, Octavia MK1) https://www.mytyres.co.uk/rims/details?vehicleId=54804057574949988&rimCode=ALCAR7600