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Discussion Starter #1
Hi Guys,

Need some advice, I have just bought a 2012 2.2dtec EX which comes with 16" rims which are upgradeable to 17" rims. Now if you bought an EX-GT model which is basically as I understand the same car with a few extra toys you can have 18" rims as an upgrade option.

The offical word from Honda is that the cars are setup to only except as wheel upgrade of 1" from the standard setup and can't see why there would be any differnce in chassis/suspension setup between the EX and EX-GT model.

Can anybody shed some light on this grey area, as this is exactly what they used to say about the last generation civic and people have been putting 19" on them. Please help..............

Dave
 

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Arfurs right hand man
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the stds on the EX are 205/55 R16 upgradeable to 225/45 R17's. on the EX GT the 225/45 R17's are the std and upgradeable to 225/40 R18.

I can never remember how the ratios work but think it may be something to do with that?
 

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Discussion Starter #3
OK, so you think it maybe something to do with gear ratios. I wouldn't have thought the gearing would be any different on an EX or EX-GT model though.

The mystery continues, guess until someones actually got them on a non GT car the are gonna find out.

Dave
 

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and bigger tyres means speedo gonna be out by a bit so will need re calib
 

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Discussion Starter #6
Re : Wheels

OK That then lead's onto another question in that if 18" rims do indeed fit on a standard EX model will you be able to tell the diagnostics that you now have 18" boots underneath the car.
 

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#MrGrumpy
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OK That then lead's onto another question in that if 18" rims do indeed fit on a standard EX model will you be able to tell the diagnostics that you now have 18" boots underneath the car.
If you're thinking for speedo issues, the difference is very small as the tyres are almost identical in outer diameter if you're using the correct profile as Daedalus said above me.
 

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Discussion Starter #8
Re : Wheels

OK, if indeed no calibration is required. Why would Honda advise that you can't use 18" rims on the new Civic apart from the GT model.
 

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Discussion Starter #10
Re : Wheels

Wacky,

Sh_t the bed thats a real nice ride, love the white but because I had a white CRZ before I opted for the black.

Any issues with speedo being out or any gremlins inside the cabin, what alloy's are they if you don't mind me asking.

Dave
 

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Just to help the first set of numbers are the thickness of the tyre in mm, the second set of numbers are the width of the wall in % of the thickness of the width and the last set are the size of the wheels in "

So for eg:

225/45 17R

225mm width
101.25mm thick side wall
17" alloy

Total diameter: 533.05mm (53.305cm)

Another eg, if you were to fit the 19" rages:

225/35 19R

225mm width
78.75mm thick side wall
19" alloy

Total diameter: 561.35mm (56.135cm)

So in total, by fitting the rage alloys the overall size is increased by 28.3mm (2.83cm)

Basically if the with doesn't rub the inside and the height increase (minimal) doesn't touch the top. You should be ok.

Hope that helps you guys :)
 

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OK, if indeed no calibration is required. Why would Honda advise that you can't use 18" rims on the new Civic apart from the GT model.
Marketing, they don't want people spending £24k on EX-GT being miffed by £19k base model looking the same, all car companies do it :police:
 

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#MrGrumpy
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Just to help the first set of numbers are the thickness of the tyre in mm, the second set of numbers are the width of the wall in % of the thickness of the width and the last set are the size of the wheels in "

So for eg:

225/45 17R

225mm width
101.25mm thick side wall
17" alloy

Total diameter: 533.05mm (53.305cm)

Another eg, if you were to fit the 19" rages:

225/35 19R

225mm width
78.75mm thick side wall
19" alloy

Total diameter: 561.35mm (56.135cm)

So in total, by fitting the rage alloys the overall size is increased by 28.3mm (2.83cm)

Basically if the with doesn't rub the inside and the height increase (minimal) doesn't touch the top. You should be ok.

Hope that helps you guys :)
Not quite fella.

225/45/17

225mm wide
101.25mm tall
17" = 431.8mm alloy

Total diameter: 431.8mm + (101.25mm x 2) = 634.3mm

Another eg, if you were to fit the 19" rages:

225/35/19

225mm wide
78.75mm tall
19" = 482.6mm alloy

Total diameter: 482.6mm (19") + (78.75mm x 2) = 640.1mm

Tyre difference is 6mm in diameter. The difference in tyre size will mean that at 70mph real speed, your speedo will indicate 70.65mph.

Negligible difference IMO.
 

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Not quite fella.

225/45/17

225mm wide
101.25mm tall
17" = 431.8mm alloy

Total diameter: 431.8mm + (101.25mm x 2) = 634.3mm

Another eg, if you were to fit the 19" rages:

225/35/19

225mm wide
78.75mm tall
19" = 482.6mm alloy

Total diameter: 482.6mm (19") + (78.75mm x 2) = 640.1mm

Tyre difference is 6mm in diameter. The difference in tyre size will mean that at 70mph real speed, your speedo will indicate 70.65mph.

Negligible difference IMO.
Oops, that was a silly mistake to make not including 2 sidewalls into it haha, in my defense I've not long woke up from a night shift :)

Thanks for the correction though
 

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Discussion Starter #17
Thx, guys so what would I need for an 18" rim, guess 19" might look out in the arch but it's a trade off for comfort.

Dave
 

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Wacky,

Sh_t the bed thats a real nice ride, love the white but because I had a white CRZ before I opted for the black.

Any issues with speedo being out or any gremlins inside the cabin, what alloy's are they if you don't mind me asking.

Dave

No problems at all. speedo is normal 4-5mph out against the sat nav. Alloys are Bobets LV5 and are 2kg lighter than the std ones so better all round. Wheel specs are exactly the same as 8th gen civics.
 

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Discussion Starter #19 (Edited)
Cheers wacky, as per your previous thread on the new rims did you then base the LV5's on the same individual spec in the 8th gen blade alloys.

Dave
 
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