Hi guys,

I've got a set of Claws and I'm needing new tyres. I've heard of people fitting 225s to their 215 alloys and I'm tempted to do the same myself with some 225/45/R17s - just a few questions though...

Does the overhang help prevent curbing? I haven't curbed my alloys yet so it would be nice to have the reassurance that if I did get a bit close to the curb, the overhang might help prevent the alloys getting damaged (main reason I'm consider 225s to be honest.)

Do the 225s noticeably wear any quicker than 215s with them being slightly too wide for the rims?

Are they an easy fit for the tyre fitters or are they likely to moan about it?

Cheers guys

May be interested for next set also, more for the look of filling the arch more(less gap)
And also for the larger rolling circumference(more mpg?)
The speedo should read slightly out also(low) but nice to hear off people who have them fitted.
I cant imagine theres any issue for fitters, i remember the days i used to get 205's on instead of 185's (on a 6 inch rim)
Also look for tyres with extra rim protection( i think some have a real good extra strip of rubber to protect rim)

i fitted 225 /45/17 on my Stilo without any problems - looks very good and some extra protection for the rims.
No noticable extra wear compared to 215's - when you fit these kind of tyres this is done for the better looks and handling in most cases , when you want to drive economically you better keep the standard tyres......

You can fit anything from 205 - 225 without a problem. You cant change the tyre height, it must be 45. If you change that you will be breaking the law as it will alter the speedo readout by a few mph.

Hope that helps.

The 45 is a percentage of the tread width, so a 225/45r17 will still read out on speedo compared to a 215/45r17.
Usually if you want to keep the same rolling circumference if you go wider you have to go lower profile like a 225/40r17 may be closer to original circumferance.
Tyre diameters
215/45r17=626mm
225/45r17=634mm
245/40r17=628mm
235/40r17=620mm
I dont think the bottom 2 will fit alloy anyway just example.
Speedos usually read high a few % it wouldnt supprise me if the 225/45r17 wernt close to real speed
Actual % according to here is only 1.44% out
http://www.etyres.co.uk/tyre-size-calculator

Xen said:

... it would be nice to have the reassurance that if I did get a bit close to the curb, the overhang might help prevent the alloys getting damaged (main reason I'm consider 225s to be honest.) ...

Click to expand...

I’ve noticed that FIAT don’t always match optimum rims with tyres. Although in this case I note from my Stilo OH that they do, 7Jx17 rims are optimum fit for 215/45R17 tyres – but then 7Jx17 are still `approved’ for 225/45R17 tyres.

To compare & contrast 215 v. 225 would depend on the individual attributes of your short-list of tyres.

Save yourself any hassle & select from 215/45R17 tyres with rim protection.

Edit
All the (within spec) Stilo tyres roll at 813(±6) revs/ml.
225/45R17 roll at 808 revs/ml - & wouldn’t cause any speedo problem any more than would 195/65R15 (that cover the most ground per tyre revolution).


141044Z

I actually have 205/45/17's on my abarth, because... the 215's were rubbing on the selespeed geerbox casing whenever I had to steering on full lock.. not sure why but just works for me

interesting post, I'vebeen thinking about this myself but i also wanted a higher tyre purely for comfort as the roads round here are pretty poor.

so is this not possible then, only wider?

When I had the original 15s on my Stilo I had 195/65 tyres on them but I had a spare set of 185/55 tyres in my garage, compared to the original tyres they had a much lower circumference, so I thought I'd try them on. On my 1.2, with lower circumference tyres, I noticed that the car accelerated better and was a bit more responsive, less effort was needed to move the wheels which for the small engine in my Stilo came as a benefit.

due to mot law changes this year ive had to get a cat rewelded back into my exhaust that had been decatted for a few years, anyway long story short its scraping on the odd shaped speed bumps it clears some and catches others and I welded it in so only myself to blame.
now then I was thinking of going up a tyre size anyway next set but now im thinking as im already low on eibachs , and they may have settled over the years I could do with an extra 10mm sidewall height.
so 225/45r17 would give me extra 4.5mm sidewall(old worn tread to new tread difference)
and a 225/50r17 would give me an extra 16mm sidewall(5.12% difference)
but if compared to a shumacher on 18" alloys difference is only 3% bigger.
I wouldn't mind the extra sidewall for comfort either as potholes are doing my head in.
anyone fitted 225/50r17 ? I know tyre calcs recommend changes within 2.5% but 3% is pretty close
ps this would be just on front axel as rear are newish 215/45r17s(and if legal would follow to larger tyreas next change)
have scoured a few mot websites and cant see any regs on sidewall profile %.
havnt actually seen mot checking speedo accuracy when watching them do brake teasts on rolling road? is it checked.

Just checked speedo against an iphone app gps and at 70mph speedo i was 68gps so under by 3%
Going up id be reading worst case 6% lower ie actual speed 74mph for speedo 70mph, and thats worst case more likely 3mph or less.
Will double check with satnav as app kept dropping signal so doubting it a bit.
Also measured hub heights on front to back and due to engine weight front sits 10-12 mm lower to ground due to wall flex even at higher pressure(higher than rec at 36psi+ fronts)

Not sure, but you may get an ABS warning if the front and rear rolling circumferences are different.
.

ive bitten the bullit to try some 225/50r17.
wont get till next week some time, will feed back any side effects with asr abs etc and also clearance issues although im on lowered eibachs and spacers(15mm).
if all ok I will feed back on any comfort change, over potholes.

just back from tyres being fitted
good news bad
good news tyres are on ,
didn't catch on anything on drive home (close to spring catcher)
if they do they'll move to the backs for the MOT
have raised the front approx. 16mm that I was hoping for
are a softer more comfortable ride
didn't throw up any abs asr codes or errors
checked again gps on iphone and at 30=30mph and 69/70=70mph
bad news
during balancing the op showed me a buckle in the inner rim of offside wheel(cant believe I cant feel it on the road it looked noticeable)
looks spoilt a bit as they now sit slightly further out(were perfect with spacers)
after MOT maybe look if room to remove spacers?(close to spring catchers)
look big in the arches (with eibach drop -25mm)
do feel a bit wollowy on the road(to be expected really)
will update again after a few days driving
and if I can find a nice flat picture opportunity ill take some pics.

heres a pic
I wouldn't recommend to anyone else

2 days in row , on same road at same corner , made noise like hitting grid so im sure arch inner edge is touching tyre.
will have a look tomorrow and maybe look at doing the ghetto arch rolling thing with a baseball bat.
feeling under the arch the inner lip does feel to be fairly large 10mm +

another week on, still not recommending this size its definitely too big for the 3 dr arch.
strangely the speedo is spot in but not enough room inside arch liners at full lock , the outer edge of the tyre is scuffing the arch liner by footwells, ive had the wheel off and theres no other sign of contact around front arch liner or inner wing or wishbone/chassis area just scuffs on that plastic liner.
I will pop down and see mot guy again for legal guideline on amount of contact allowed.
I had a look and im estimating if it wasn't lowered it would possibly be worse as the contact would be lower towards sill which is closer to wheel if car is higher.
also if spacers weren't in it looks like would still catch that arch liner ,plus it might possibly of caught the inner arch and chassis without 15mm spacers ?
im going to try some spring assistors as a cheap band aid to see what is needed , and if necessary move to rear and put originals std size back on the front, and let the spring assistors sort out the clearance under car.

last update on these 225/50r17 tyres,
I tried the spring aids front and back(looks like raised the car back to in between pre eibach ride height and what it was)
actually made issue worse and contacted the arch liner lower down nearer the sill where it sticks out further so more contact under lock.
swapped tyres front to back, and thought it was o.k. and would last to get some life from tyres but fail again im afraid.
during a holiday with car loaded in rear(not real heavy) had to rush into decision away from home so shamefully ive had to remove off the car and scrapped due to wheel arch contact on the sidewalls at speed and momentum squatting the car down, or rapid set offs, not willing to risk safety or a blow out any further so removed for some standard 215/45r17.
also I think the mot would fail due to damage on the sidewall since moving to the rear.
picked the slivers of rubber out of my wheel arch and left at that.
some pics anyway no order











sorry got no pics of the damage to tyres but imagine a potato peeler slicing round the side wall

Ohhh. Getting caught with spring aids or compressors over here, your numberplate would be cut off immediately. It's illegal, as it alters the supposed behaviour. Is it okay to use in the UK?

I will let you know later ?
Mot today
Guys pretty good if he says no way, ill remove while he has up on ramps and either go back to cat grounding on ramps or put back in after mot.
Ive noticed no real difference to spring behaviour since having them in just a slightly higher ride height closer to oe.
Maybe the eibachs are stiffer than the rubber ?