175 Tyres On A 6.5 Inch Rim

October 20, 2009

I was wondering if anyone has fitted 175-50-R15 tyres on a set of 6.5 x 15 inch rims? The usual tyre quoted for this size of rim is 195-45-R15, but I understand that this can give rise to rubbing off the rear arches on the 5dr Aygo with passengers in the back.

About 99% of 15 inch alloys available are 6.5 inches wide, there is a poor selection of 6 inch wide rims which would be a better match for a 175 tyre.

October 20, 2009

1st of all a 175/50x15 tyre will happily sit on rims between 5J and 6.5J rims, so in that respect there is absolutely no problems whatsover. I have fitted lots of them... I'm a tyre fitter :lol:

As for rubbing with 195/45x15, this will depend on the offset of the wheels because 195/45x15's actually have a smaller rolling radius than the standard 155/65x14's...

155/65x14

Rolling Radius - 278.55mm

Circumference - 1750.18mm

195/45x15

Rolling Radius - 278.25mm

Circumference - 1748.29mm

Difference in circumference - -1.89mm or 0.11%

As you can see other than the width of the tyre, the 195/45x15's are actually a little smaller, not by much, but smaller just the same, than the standard tyre. Opting for 175/50x15's instead of 195/45x15's won't make too much of a difference as the sidewall of the tyre (which is what might rub) will still be in the same place no matter what the size, as this is determined by the width of the wheel (J size), both sizes will still need to fit all the way to the edge of the rim... the only minor diference would be a couple on mm's of streatch in the narrower tyre, but the centre of the sidewall will be in the same place.

175/50x15

Rolling radius - 278mm

Circumference:1746 - 72mm

Difference in circumference - -3.46mm or -0.2% over the standard 155/65/14's

As you can now see all 3 sizes are more or less the same in overall circumference and rolling radius, so no problems in that respect, this is where the width of the rim and the offset come into play, the offsets for the Aygo are between ET35 and ET45, the wider the wheel the less offset you have to play with... see below for an explanation of how offsets work.

Offset Explained

The offset is the distance between the mounting surface and the centre line of the wheel, it is always measured in millimetres.

If you sit the wheel down on a flat surface and measure the width of the wheel, divide it by 2, you get the centre line. The offset is then the difference between this centre line and the point in which the wheel comes into contact with the hub (mounting surface). The bigger the offset, the closer it will sit to the strut, the smaller the offset, the closer it will sit to the arch.

Example :- ET35 will sit closer to the wheel arch than ET45.

Recommended tyre sizes for the Aygo...

155/70x13

155/65x14

165/60x14

195/45x15

195/40x16

Although I have mentioned a streatch in my post earlier, the sreatch is so slight you wouldn't really notice it, but as the tyre sidewall reaches the tread there will be a slight difference (narrower) at that point, but only a few mm.

Not being an Aygo owner I'm not in a position to say which offset would be the best for a 6.5J rim on the Aygo, felow Aygo owners are in a better position than me to answer that, but I would think a larger offset would be better as it would keep the wheel further away from the arch, so perhaps in the region of ET40 would be best... but please don't take my word for that, wait till people with the relevent experience confirm or correct me on this. I do feel however that I have answered your question on tyre sizes, it won't make much difference to the car... but the 195/45x15's will be easier to get and will probably be cheaper as it is a more common size.

October 21, 2009

195/45 R15 with offset 37 is ideal. But, I knew it rubbed. So, i got offset 38, and it still rubs. Yep, I also think that offset 40 will solve the problem on 195/45 R15.

I've had the same ideea as the OP about 6 months back, using the tire specs from http://www.tte.de/popup/TTE/cm_aygo_wheels_TTE.htm i wanted to fit them on a 6.5J wheel. Didn't get around to it, I think it's easier to roll the arches and it won't rub anymore :)

Ps: great post - explaining :)

October 21, 2009

Morning all.

everything written above is 100% right.

But road experience is much more valuable...

i own a Aygo 1.0 2007, 5d, MMT, with standard alloy Toyota wheels 14''. It came with tyres Continental 155/65/14, and it was terrible... meaning that when you ''push'' it in turns, corners, etc, it had no traction. when rainining, the problem was multiplied 10 times.

So, talked with my rubber - man, and told me to fit 165/60/14.

also changed springs with a set af APEX, vehicle lowered 30mm, and it was transformed. Didn't change wheels, and 3 years i enjoy it.

Need to say, that those dimensions are more cheper and you do not bother with problems about tachometer, snow, ( chains will they fit in the arch with 195??), fuel consumption, etc....

Vehicle was also acting much more better with 165/60/14, before i fit the springs.

I live in Greece, and heavy weather, is an unknown word here, but we have to consider about the worst roads in Europe..

Hope i helped a little, pardon me about my English.

October 21, 2009

I'm not convinced it is rubbing on the wheel arches, I think it more likely that it is rubbing on the the pipe that leads to the fuel tank on the passenger side. This would be worse with wider wheels and tyres as mentioned by cfc1 because a 195/45 15 is less than the standard wheel size and higher profile tyre by smidgen.

Regards

Andy

October 21, 2009

Thanks for the detailed feedback cfc1, and thanks to everyone else for your responses.

I had my heart set on 15 inch rims, but it sounds like the only way to minimize / eliminate tyre rub at the rear is to use a 15 x 6 inch rim with an offset to keep the rim in from the arch as much as is practical, combined with a 175 50 R15 tyre. I'm not comfortable with getting the arches rolled, as its almost impossible to get someone I can trust to do it right and not make a b*lls of it around where I live. The number of times I have been disappointed with mechanical and bodywork repairs done by so called professionals really gets me down.

I have considered 14 in rims, the standard width for this size of aftermarket wheel is 5.5 inches so the 165 tyres will fit fine.

The roads in the west of Ireland are pretty crap too, so when taking everything discussed into consideration, I think the path of least resistance is the 14 in rims in conjunction with the 165 tyres...

Thanks again guys.

Kevin

October 22, 2009

Thanks for the detailed feedback cfc1, and thanks to everyone else for your responses.
I had my heart set on 15 inch rims, but it sounds like the only way to minimize / eliminate tyre rub at the rear is to use a 15 x 6 inch rim with an offset to keep the rim in from the arch as much as is practical, combined with a 175 50 R15 tyre. I'm not comfortable with getting the arches rolled, as its almost impossible to get someone I can trust to do it right and not make a b*lls of it around where I live. The number of times I have been disappointed with mechanical and bodywork repairs done by so called professionals really gets me down.
I have considered 14 in rims, the standard width for this size of aftermarket wheel is 5.5 inches so the 165 tyres will fit fine.
The roads in the west of Ireland are pretty crap too, so when taking everything discussed into consideration, I think the path of least resistance is the 14 in rims in conjunction with the 165 tyres...
Thanks again guys.
Kevin

I've got 15x6.5 offset 40 with a 195/45 tyre and lowered suspension and there is no rubbing. I used to have 16x7 with 37 offset (not lowered) and there was only a problem over very bumpy roads with those, still didn't hit the arches though, it was the fuel pipe ! I think you are being conservative.

Regards

Andy

October 22, 2009

Yes, I agree that I'm being conservative, but the other factor that increases the chance of tyre rub is carrying rear passengers, which I do regularly on the school run. I'll see whats available in a 15 x 6 rim with a suitable offset. Failing this, I'll go for the 14's.

Thanks for everyones feedback on this, it will help me make a more informed decision. :)

October 23, 2009

Yes, I agree that I'm being conservative, but the other factor that increases the chance of tyre rub is carrying rear passengers, which I do regularly on the school run. I'll see whats available in a 15 x 6 rim with a suitable offset. Failing this, I'll go for the 14's.
Thanks for everyones feedback on this, it will help me make a more informed decision. :)

Ok, good luck. Wouldn't want you to curse me forever if they did rub ! :D

One advantage of 14 inch wheels are they are a bit lighter than 15, with a low powered car like the Aygo every little helps!

Regards

Andy

October 23, 2009

They only rub if you put 2 people in the back, each more than 80 kg, and will hit bumps at high speed. And the rubbing is minimal, about 1-2 mm.

October 25, 2009

14x6 et 38 with 185x55x14 tyres fits with no rubbing B)

Paul.

October 25, 2009

I was thinking of 14 x 6 inch rims, but wouldn't need the grip of a 185 tyre. Saw you car Paul in the latest edition of Banzai. Looks very good on those rims.