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Alrighty,
Need a couple of new tyres for the wife's car, i'm looking online at some reviews and double check the manufacturers site for the size & apparently I need 205/45 16, the tyres fitted on the car however - which were on there when she bought it from a main dealer - are 205/50 16.
Have had a look around & apparently when changing tyre sizes there ideally would be less than 0.5% and not any more than 1% difference in overall diameter (in this case it's 1.03%) - what would STW do?
Change 2 tyres for the same size as fitted
Change 4 tyres to the proper spec
Have a chat (at the top of my voice in the middle of the showroom swinging bombers) with the dealer - car is not long out of the 1 yr no-quibble warranty annoyingly
Cheers,
John
Www.willtheyfit.com
Shows as a 3.35% difference in speedo reading between the 2 sizes.
Personally I would go for all four the same, in either size.
What he said, it's aspect ratio so 5% of 205 (10mm, 20mm overall on the diameter), probably a lot more than 1%.
I'd replace all 4 if they're anything like worn out. Some cars don't like mismatched wheels as it messes with the abs and traction control if one set of wheels is spinning faster than the other.
A year in then asking for new tyres might be a bit cheeky, some people / cars would wear them out in that time! Might be worth asking (mention that you're worried about insurance implications of undeclared modifications) but getting more than some goodwill and a voucher might be lucky.
Some slight variations end up a lot cheaper as 15-20 years ago almost all cars had the same sizes, these days even basic cars come spec'd with unusual sizes. So changing size might save quite a lot if it's to something more popular.
The rears are totally fine, so if i'm staying with the same size - not specced by the manufacturer - it's 2 I need, if there's an possible issue with the bigger size (handling / speedo out etc etc) & I need 4 new tyres i'll probably be asking the dealer why they sold us a car with the wrong size tyres.
I'll phone the dealer & ask if I can use bigger tyres - if they say no i'll ask whey they sold it like that then, before taking to the t'internet and besmirching their good name, as is the socially accepted norm these days.
We actually had another car the same before this (some buffoon crashed into it when it was parked & wrote it off) and I always felt the new one felt a bit different somehow, probably my imagination but now i'm wondering...
J
probably my imagination but now i’m wondering…
I wouldn’t wonder too long 👍
No way you could “feel” the difference in those sizes.
I wouldn’t wonder too long 👍
No way you could “feel” the difference in those sizes.
Aye, it's probably the fact the old one had about 70k on it and the newer one had 20 😀
On the price thing - the 205/50 seems to have much more choice so that's probably why it ended up with them being fitted, probably by the original owner who traded it in...
The tread and sidewall difference will make a huge difference to feel - but not 5% bigger or smaller.
We to have an odd 215/46/16 wheels car, narrow choice of tyres, plus overkill on a 75bhp Ibiza. The other Ibiza's have much cheaper tyres and 15" rims.
Insurance invalidation if changed from factory spec.
That's more what i'm concerned about tbh - the manufacturer states 205/45 for that size wheel...
Insurance invalidation if changed from factory spec.
Only if you don't declare it.
Insurance invalidation if changed from factory spec.
Only if you don’t declare it.
Which would be pretty difficult if it was not known.
Insurance invalidation if changed from factory spec.
do you have a source for that or is it the old wives tale again.
The effect on circumference is what matters to the car's electronics. The difference isnt huge.
I wonder if the previous owner changed the sidewall height because he/they found the ride too harsh. When you are at or around 50 you do start to feel relatively small differences
The answer of whether to change 2 tyres or 4 might depend on this:
Why do only 2 tyres need replacing?
It could be the car had not the right size fitted at the factory. I bought my car at 1600 miles and the tyres come up the wrong size for my reg number (225/55/16) tyres actually fitted are 225/60/16 I assume the production line wasn't stopped for the right sized tyres and these were fitted instead.
Why do only 2 tyres need replacing?
I'm not a fan of replacing one tyre at a time, even for the same type - it's fronts or rears or everything.
My wife wrecked one front tyre on a huge pothole recently & just drove into the nearest tyre place and replaced it with the cheapest available - so currently the fronts are mismatched and I can feel a noticeable difference between them, I also noticed at the weekend the original front is worn on the inside edge - alignment out somewhere - so that needs replacing & I really don't want 2 of the shitty plastic feeling efforts on there, so for the sake of an extra £50 for peace of mind that's getting ditched too.
It could be the car had not the right size fitted at the factory. I bought my car at 1600 miles and the tyres come up the wrong size for my reg number (225/55/16) tyres actually fitted are 225/60/16 I assume the production line wasn’t stopped for the right sized tyres and these were fitted instead.
VAG group trying to get the fuel economy figures up? #marginalgains 😀
No mcj citroen C5 but i do get the claimed MPG
It'll be fine, drive on.
, I also noticed at the weekend the original front is worn on the inside edge – alignment out somewhere – so that needs replacing
That was partly what I was wondering. Uneven wear on tyres of unknown origin/vintage (although the age of the Tyre is on the sidewall the mileage is presumably unknown) could mean that they haven't been cared for and rotated and balanced properly, so at that point is it worth doing all 4 at the correct size for peace of mind?
I only say that as ours is a Skoda - the first one I refused to take back for the emissions-scandal software "upgrade" and the second one (identical car) already had it done when we bought it, felt like a completely different engine...
That was partly what I was wondering. Uneven wear on tyres of unknown origin/vintage (although the age of the Tyre is on the sidewall the mileage is presumably unknown) could mean that they haven’t been cared for and rotated and balanced properly, so at that point is it worth doing all 4 at the correct size for peace of mind?
TBH they probably haven't ever been rotated - certainly not since we've had it, but I know what you mean - had a proper look at the rears and they're completely even wear-wise & still look quite new, if they were slightly more worn or cut up i'd replace all 4 and go back to the "normal" size but I don't want to spend another £100-odd unless I have to
It’ll be fine, drive on.
This is my preferred option 😉
Mismatched tyres left /right will cause more handling discrepancies than a tiny change of profile in front /rear assuming you change tyres in pairs.
Different make/different compound /different tread depth.
I'd always replace both front or both rear unless the bust tyre is almost new, and only then with the same size and model tyre.