Imi7

14 hours ago, steve2006 said:

That change of tyre size would result in an increase of around 35mm on your sidewall height, this increased flexibility could affect your handling of the car due to the extra give in the tyre. Suspension set up and geometry on road cars are generally designed as a compromise between road holding characteristics and comfort  and this includes the size of the tyres.

Personally I would stick to the recommended size.

Thank you - after the advice on here I have decided to stick with the original sizes. 

Next Q - what tyres would members recommend for the CT?

Just now, NemesisUK said:

That would be an interesting conversation, please let us know how it goes.

I'm not sure how you can come to that conclusion? 

Apologies - I edited my statement to read it would not be ok 🙂

2 hours ago, NemesisUK said:

Do you really mean 225/50 section?

Under UK law - which is based on a European Union standard - speedometers must never underreport a vehicle's speed, while it must never overreport by more than 110% of the actual speed + 6.25mph. So if you're going 40mph, your speedometer may read up to 50.25mph - but it can never read less than 40mph

Calculator

@NemesisUK Thank you for the calculator.

Yes - I am proposing to replacing stock 215/45 R17 with  225/50 R17.

Looking at the calculator,  if I was showing 70 mph, then my actual speed on the new proposed tyres would be 73.53mph, so under the definition of the law this is not allowed - but aren't cars speedo's calibrated to over report the speed by a certain %? I will be checking with my insurance company to ensure they are happy with the 'mod'.

Question is - has anybody else changed their tyre sizes away from the stock size of 215/45 R17? I have read another thread on this forum someone did this and noticed a huge improvement in the comfort.

Or - I can just stick to the normal size when I change the tyres :). 

The tyres on my CT200h are all due to be changed. I am currently running stock 215 45 17 Yokohamas - could I replace them with 225 50 17's? I am aware that it may affect the speedo reading by 2-3% , which is fine.

Thanks in advance.