17" Alloys Tyre Sizes ?

[Brendan3006]

Hi Guys,

I'm new to the CT200h and to this Forum.

I'd appreciate if anyone could help me with a query about tyre size on my 2015 CT, please.  It currently has 215/45/17 Yokohamas, which are quite harsh and noisy on rough surfaces.

I have considered changing to 16" wheels to help resolve the issue but my local tyre shop say I could fit 215/55/17's to try and address the problem.  Does anyone know if this can be done without the tyres catching the arches etc?

Your advice will be appreciated and thanks in advance.

[H4ndyAndy]

Hi Guys,
I'm new to the CT200h and to this Forum.
I'd appreciate if anyone could help me with a query about tyre size on my 2015 CT, please.  It currently has 215/45/17 Yokohamas, which are quite harsh and noisy on rough surfaces.
I have considered changing to 16" wheels to help resolve the issue but my local tyre shop say I could fit 215/55/17's to try and address the problem.  Does anyone know if this can be done without the tyres catching the arches etc?
Your advice will be appreciated and thanks in advance.

Have you done it ?
What's the outcome ?

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[ColinBarber]

That is nearly a 7% increase in circumference - normally more than is acceptable to keep the speedo/odometer within spec. Although it would actually make the speedo nearer to actual speed rather than reading over by design.

[H4ndyAndy]

How about a narrow option, like 205/55/17 ?

[ColinBarber]

6 hours ago, H4ndyAndy said:

How about a narrow option, like 205/55/17 ?

That would still be 5% out. You would need to go down to 175/55 to be the same be the same - which you wouldn't want to do and probably too narrow for the rim.

If you are looking to improve the ride comfort then 15" or 16" rims are the way to go.

[H4ndyAndy]

Is this right ?

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[ColinBarber]

Yes the offset piece is correct because it is just referring to the rim. You haven't change the rim offset or width so it is in exactly the same place as before.

You can see from the diagram the tyre new tyre is taller, 16mm.

215 mm x 45% = 97 mm

205 mm x 55% = 113 mm.      Difference is 16 mm on the side wall.

Therefore the diameter of the tyre will be 32 mm different. The vehicle will be 16 mm higher and the gap to the wheel arch will be 16 mm less.

[Brendan3006]

Hi Guys,

Having considered all the options I have eventually changed my tyres from the original 215/45/17 to 225/50/17's. My local tyre shop were very helpful and fitted these to try out while giving me the option of changing them back again within a day or two if they was any problem or if I wasn't happy.

The new sized tyres transformed the car completely and now it feels and drives more quietly. It is vastly more comfortable on the road, and feels like a luxury vehicle should. The tyres also look much better while filling the wheel arch more and the car sits slightly higher. I can't understand why Lexus persist with fitting the lower profile tyres.

I checked with my Insurers and they have no problem with the change. Also, I checked the speedo against my Sat Nav and an independent App on my Phone and both confirm the car's speedo is now accurate i.e. I have lost the manufactures built in leeway but I can live with that.

Thanks for the previous advice.

 

[Mr Vlad]

Yokahama tyres do give a harshish ride. You could have stuck with the same size tyre but gone for a different brand. Plenty to choose from. What brand are the 255's then?

[Brendan3006]

Goodyear Efficient Grip (with a low noise rating of 67db)