Mk3 to mk2 alloys
- Thread starter Jordanw20
- Start date
What’s the width and offset your existing alloys and the 18” set you’re thinking of fitting? - the spec of the alloys should be stamped into the reverse side of the spokes. If you use the calculator at www.willtheyfit.com and input details of your existing and new wheel / tyre set up, then it will calculate differences in tuck and poke so you’ll be able to determine whether or not you’d have any clearance issues.
Irrespective of width and offset of the wheels and potential clearance issues, bear in mind that 18” alloys with 225/45 R18 tyres will result in a larger overall circumference and rolling radius than your current wheel / tyre set up so your speedo reading will be inaccurate; it’ll under-read by roughly 4%, so when your speedo is indicating 60mph, your actual speed will be around 62.5 mph
The last paragraph of article at the link below states that legally in the UK, a car’s speedo shouldn’t under-read / should never, show less than the actual speed, so you’d need to consider changing the tyres on the 18” alloys to a lower profile to eliminate the speedo under-reading error.
www.thecarexpert.co.uk
Irrespective of width and offset of the wheels and potential clearance issues, bear in mind that 18” alloys with 225/45 R18 tyres will result in a larger overall circumference and rolling radius than your current wheel / tyre set up so your speedo reading will be inaccurate; it’ll under-read by roughly 4%, so when your speedo is indicating 60mph, your actual speed will be around 62.5 mph
The last paragraph of article at the link below states that legally in the UK, a car’s speedo shouldn’t under-read / should never, show less than the actual speed, so you’d need to consider changing the tyres on the 18” alloys to a lower profile to eliminate the speedo under-reading error.
How accurate is your car speedometer? #AskTCE
Have you noticed that your car speedometer reads faster than your satnav says? Find out why this happens in this week's #AskTCE at TheCarExpert.co.uk
www.thecarexpert.co.uk
Both are 5x112What’s the width and offset your existing alloys and the 18” set you’re thinking of fitting? - the spec of the alloys should be stamped into the reverse side of the spokes. If you use the calculator at www.willtheyfit.com and input details of your existing and new wheel / tyre set up, then it will calculate differences in tuck and poke so you’ll be able to determine whether or not you’d have any clearance issues.
Irrespective of width and offset of the wheels and potential clearance issues, bear in mind that 18” alloys with 225/45 R18 tyres will result in a larger overall circumference and rolling radius than your current wheel / tyre set up so your speedo reading will be inaccurate; it’ll under-read by roughly 4%, so when your speedo is indicating 60mph, your actual speed will be around 62.5 mph
View attachment 28932
The last paragraph of article at the link below states that legally in the UK, a car’s speedo shouldn’t under-read / should never, show less than the actual speed, so you’d need to consider changing the tyres on the 18” alloys to a lower profile to eliminate the speedo under-reading error.
How accurate is your car speedometer? #AskTCE
Have you noticed that your car speedometer reads faster than your satnav says? Find out why this happens in this week's #AskTCE at TheCarExpert.co.uk
5x112 is the PCD (pitch circle diameter) which is the same for many VAG cars, including the mk2 and mk3 Leon, which means the bolt holes in the wheels and wheel hub assemblies will line up correctly. Both the mk2 and mk3 Leon have the same centre bore size too (57.1) so if the 18” alloys you’re considering are genuine OEM Seat alloys, it won’t be necessary to fit spigot rings.
However, offset and wheel width are additional factors that need to be considered when fitting different wheels to a car, to ensure the inner face of the wheel doesn't make contact with the suspension struts and the outer face doesn’t protrude out beyond the wheel arch edge.
However, offset and wheel width are additional factors that need to be considered when fitting different wheels to a car, to ensure the inner face of the wheel doesn't make contact with the suspension struts and the outer face doesn’t protrude out beyond the wheel arch edge.
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Your standard 17" wheels are 7.5J x 17H2 ET51, if the MK2 18" wheels are similar offset (ET49 to ET 51) they should be OK, the only thing is that the tyres should be 40 profile not 45.
The tyre size difference means the speedo won’t read correctry, if your original post is correct. The tyres are both 225/45, so have the same sidewall height ( 101mm approx), but one is 1” bigger diameter, so the 18” rims with the 225/45 tyres are a bigger circumference, meaning your speedo will under-read, by 12%. So at an indicated 30 you’ll be doing 33.6. And a a “safe” (from a speeding ticket POV) 35 you’ll be doing 39, and get nicked.
@rafletcher; great minds think alike
- see my post no.2 in this discussion thread.I think the speedo error will be less than 12% though; using a couple of the on line calculators that’ll work out the impact on speedo reading of changing the diameter / rolling radius of the wheel / tyre set up, both calculators suggest the speedo would be under-reading by around 4% - still too much though; it’s permissible for a speedo to over-read but it shouldn’t under-read. Screen shot of the results of one of the calculators is in my earlier post.
The photo has 225/40/R18 tyres, so ok.
You can get the rim sizes from part numbers here:
seat.7zap.com
7.5J and ET51
And part numbers from the wheels fitted:
seat.7zap.com
7.5J and ET51
You can get the rim sizes from part numbers here:
aluminium rim; hub cap Leon/Leon 4 (LE) 2011 year Seat EUROPA 601060
aluminium rim<br/>hub cap Leon/Leon 4 (LE) 2011 year Seat EUROPA 601060 spare parts
7.5J and ET51
And part numbers from the wheels fitted:
aluminium rim; hub cap Leon/Leon 4 (LE) 2014 year Seat EUROPA 601055
aluminium rim<br/>hub cap Leon/Leon 4 (LE) 2014 year Seat EUROPA 601055 spare parts
7.5J and ET51
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@black_sheep; well spotted on the tyre size! I wonder why the OP said they were 225/45 R18? Maybe the existing 225/40 R18 tyres were badly worn, and they’d found a set of well priced 225/45 R18’s that they were hoping to use as replacements.
Assuming you’re referring to the alloys in the pictures posted by @Jordanw20 in the first post of this discussion topic. If so, a quick internet search gives the part number as 1P0601025Q (size; 7.5J x 18, offset ET51).
If you do a search on the part number, you’ll see from the images that they’re the same alloys as those in post #1 above. Looks like there were two colour options - gloss black and what looks like silver (or possibly white? difficult to tell from the internet pictures), so if you can’t find a gloss black one, you might have to go for the other option and get it painted / powder coated to match your existing alloys.
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