tyre size

super s · 28th May 2017, 17:35

hi everyone...

can someone tell me if it is possible to put a 245.45.18 in the 18 inch straight... as most of you know, the regular size is 225.45.18..

this is because i found a good price for a set of four, but dont know if they fit...

can someone help...???

thanks in advance.

Tim · 28th May 2017, 17:53

You will struggle with that size. The 45 may also put your speedo etc out on 18's" I have 235/40/18's on my ZT with no issues.

super s · 28th May 2017, 18:06

ok... about the speedo it could have a gap of maybe 2.75% innacuratte...

but will they phisically fit the original straight rims 18 ???

if they fit i would like the look... more opinions???

super s · 28th May 2017, 20:23

does anyone know if it will fit the rims properly ...???

anyone please....

Dubya · 28th May 2017, 20:51

When I purchased my ZT-T it had 245/45/18 tyres fitted to the front wheels. Not sure if it was the extra width, the corresponding increase in sidewall height, or a combination of the two but on full lock the inside of the tyre would foul and rub. Changed them for 225/45/18 and all was well.

T-Cut · 29th May 2017, 15:32

A 20mm extra width over standard fit will increase the flexure around the tread centre. I once fitted 14% over-wide tyres to a mini cooper and after 10K miles they all cracked in the middle of the tread (well I was an ignorant youth). In this case, the increase is only 9% so wheel arch clearance may be more relevant.

TC

super s · 29th May 2017, 20:26

went and bought only 2 for the rear, the two for font are the standard 225.45.18...

it gives a good look of the car, at least i like... however the speddometer when i reach 120kmh activates the traction control...

believe thats because the rear wheels dont roll as the front ones... am i right???

if they are both 45 why they dont roll the same?

Coups · 29th May 2017, 20:56

Quote:

Originally Posted by super s

went and bought only 2 for the rear, the two for font are the standard 225.45.18...

it gives a good look of the car, at least i like... however the speddometer when i reach 120kmh activates the traction control...

believe thats because the rear wheels dont roll as the front ones... am i right???

if they are both 45 why they dont roll the same?

The 45 part of the tyre size is the height of the sidewall expressed as a % of the width. So they aren't the same for each of your two tyre sizes. The front ones being a smaller rolling circumference.

Sent from my iPhone using Tapatalk

T-Cut · 30th May 2017, 09:32

Quote:

Originally Posted by super s

if they are both 45 why they dont roll the same?

It's recommended not to exceed a 2.5% difference in the diameters between tyres. You can check yours using a tyre calculator like this: http://www.tyresave.co.uk/tyre-size-calculator/

TC

28th May 2017, 17:35	#1
super s Gets stuck in mg Join Date: Jun 2015 Location: porto Posts: 542 Thanks: 134 Thanked 40 Times in 37 Posts	tyre size hi everyone... can someone tell me if it is possible to put a 245.45.18 in the 18 inch straight... as most of you know, the regular size is 225.45.18.. this is because i found a good price for a set of four, but dont know if they fit... can someone help...??? thanks in advance.

28th May 2017, 17:53	#2
Tim Feel the size of my Quads MG ZT 440SE, MG HS PHEV & MG3 Join Date: Nov 2006 Location: Addlestone Posts: 1,735 Thanks: 0 Thanked 128 Times in 85 Posts	You will struggle with that size. The 45 may also put your speedo etc out on 18's" I have 235/40/18's on my ZT with no issues. __________________ Member 23 or 63 depending on what you look at. https://www.two-sixties.co.uk/mgoc26...0rum/forum.php http://two-sixties-blog.com/ http://www.youtube.com/user/TheTwoSi.../1/1wPt2rhd_Ps

28th May 2017, 20:51	#5
Dubya Loves to post 2005 MG ZT-T+ V6 190 Join Date: Jun 2015 Location: Hereford Posts: 474 Thanks: 126 Thanked 139 Times in 103 Posts	When I purchased my ZT-T it had 245/45/18 tyres fitted to the front wheels. Not sure if it was the extra width, the corresponding increase in sidewall height, or a combination of the two but on full lock the inside of the tyre would foul and rub. Changed them for 225/45/18 and all was well. __________________ 7,925th ZT-T to run off the production line, out of 8,249 The 1,709th ZT-T 190 + to be made out of 1,756 The 103rd ZT-T in Mica Blue (Ignition) (code: JGY) to be made out of 160 Mica Blue (Ignition) ZT-Ts

28th May 2017, 18:06	#3
super s Gets stuck in mg Join Date: Jun 2015 Location: porto Posts: 542 Thanks: 134 Thanked 40 Times in 37 Posts	ok... about the speedo it could have a gap of maybe 2.75% innacuratte... but will they phisically fit the original straight rims 18 ??? if they fit i would like the look... more opinions???

28th May 2017, 20:23	#4
super s Gets stuck in mg Join Date: Jun 2015 Location: porto Posts: 542 Thanks: 134 Thanked 40 Times in 37 Posts	does anyone know if it will fit the rims properly ...??? anyone please....

29th May 2017, 15:32	#6
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	A 20mm extra width over standard fit will increase the flexure around the tread centre. I once fitted 14% over-wide tyres to a mini cooper and after 10K miles they all cracked in the middle of the tread (well I was an ignorant youth). In this case, the increase is only 9% so wheel arch clearance may be more relevant. TC

29th May 2017, 20:26	#7
super s Gets stuck in mg Join Date: Jun 2015 Location: porto Posts: 542 Thanks: 134 Thanked 40 Times in 37 Posts	went and bought only 2 for the rear, the two for font are the standard 225.45.18... it gives a good look of the car, at least i like... however the speddometer when i reach 120kmh activates the traction control... believe thats because the rear wheels dont roll as the front ones... am i right??? if they are both 45 why they dont roll the same?