225/55/18 vs 225/50/18 Tyres ?

jsdh89j9ijkL · 08-30-2016, 03:08 PM

Has anyone gone from 225/50/18 to 225/55/18 sized tyres?

This is because Michelin only do 225/55/18s.

Were there any differences, speedo etc. ?

Cheers.

brissim · 08-30-2016, 05:15 PM

Well you should be able to work that out by yourself - there's no rocket science involved. The 225/55-18s will have a 22.5mm (0.9 in) larger tyre diameter than the 225/50-18s. This will result in your speedo (and odometer) reading 3% under - ie at an indicated speed of 100km/h you'll actually be going 103 km/h.

Check what your local laws are. For example here in Australia that would make your car "unroadworthy" and would void your insurance. Here you are only allowed a maximum variance from OEM diamter of +/- 15mm (+15mm / -26mm in some states).

Tony

E90Fleet · 08-31-2016, 07:30 AM

Why only Michelin ?

Here Michelin offer 225/50/18 in the Primacy 3

08-30-2016, 03:08 PM	#1
jsdh89j9ijkL Second Lieutenant 65 Rep 200 Posts Drives: motorcycle Join Date: Mar 2016 Location: there iTrader: (0)	225/55/18 vs 225/50/18 Tyres ? Has anyone gone from 225/50/18 to 225/55/18 sized tyres? This is because Michelin only do 225/55/18s. Were there any differences, speedo etc. ? Cheers.
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08-30-2016, 05:15 PM	#2
brissim Lieutenant 86 Rep 510 Posts Drives: X3 30d (2011 F25) - now sold Join Date: Jul 2011 Location: Brisbane, Australia iTrader: (0)	Well you should be able to work that out by yourself - there's no rocket science involved. The 225/55-18s will have a 22.5mm (0.9 in) larger tyre diameter than the 225/50-18s. This will result in your speedo (and odometer) reading 3% under - ie at an indicated speed of 100km/h you'll actually be going 103 km/h. Check what your local laws are. For example here in Australia that would make your car "unroadworthy" and would void your insurance. Here you are only allowed a maximum variance from OEM diamter of +/- 15mm (+15mm / -26mm in some states). Tony Last edited by brissim; 08-30-2016 at 05:46 PM.. Reason: spelling - as usual
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08-31-2016, 07:30 AM	#3
E90Fleet Lieutenant General 1312 Rep 10,185 Posts Drives: BMW Join Date: Apr 2005 Location: South Africa iTrader: (0)	Why only Michelin ? Here Michelin offer 225/50/18 in the Primacy 3 __________________ BMW if you are reading, I need a job, Please.
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