Wheel sizes and MPG

[Tomfromfife]

Hi,

My wife has just bought a CT200h Luxury ex demonstrator. I am finding the ride harsh and uncomfortable for a luxury car so I am looking at changing the wheels which are currently 17” with low profile tyres (45). 

I see that there are 15” and 16” options with higher profile tyres, which are more comfortable. I also read this in a CT200h description...

Official combined cycle fuel consumption figures were improved: 78.5mpg for the S model with 15-inch wheels; 74.3 mpg for versions fitted with 16-inch wheels; and 68.9mpg for those on 17-inch wheels.

That’s quite a difference in claimed fuel consumption, which is another benefit. Obviously nothing like the real world though.

Has anyone any advice on where to buy Lexus wheels and the price?

Does anyone want to swap our wheels for new or nearly new smalller wheels. Ours have 1800 miles on them currently.

Thanks

[NemesisUK]

Lexus would be the obvious suggestion but won't be cheap.

When I enquired about 18" wheels (for winter tyres) on my RC Lexus quoted ~£2.5k for the four..

[200h]

just make sure the wheels have come off a CT and not someone saying

they will fit a CT from memory the pcd is 102.5mm this diameter

isn't the everyday diameter for bolt holes.

[Tomfromfife]

I have 2 quotes from Lexus for 4 16x6j wheels and 205/55/R16 tyres.

First is for 4 x 16” alloys part number 4261176140 and Yokohama E70J tyres 205/55/R15. Price £1645

Second is for 4 x 16” alloys part number 4261176140 and Michelin CrossClimate tyres 205/55/R15. Price £1750

Wheels are £250.31 + VAT at £50 so £300.31 each

Yokohamas are  £58.20 + VAT  at £11.64 so £69.84

michelins are £80.30 + VAT at £16 so £96.30

Lexus do price matching on locally supplied tyres so the tyre price can be reduced

 

[Britprius]

2 hours ago, Tomfromfife said:

I have 2 quotes from Lexus for 4 16x6j wheels and 205/55/R16 tyres.

First is for 4 x 16” alloys part number 4261176140 and Yokohama E70J tyres 205/55/R15. Price £1645

Second is for 4 x 16” alloys part number 4261176140 and Michelin CrossClimate tyres 205/55/R15. Price £1750

Wheels are £250.31 + VAT at £50 so £300.31 each

Yokohamas are  £58.20 + VAT  at £11.64 so £69.84

michelins are £80.30 + VAT at £16 so £96.30

Lexus do price matching on locally supplied tyres so the tyre price can be reduced

 

You need to add to this the cost of 4 TPMS monitors for the wheels unless you intend removing them from your  original wheels.

John.

[Tomfromfife]

They are being moved from the original wheels to the new ones. The original wheels are almost new.

Standard rubber valves will be fitted to the ‘old’ wheels and will be sold

[200h]

label up each valve so you know which corner the sensor has come from

[Tomfromfife]

OK, Lexus are doing it so hopefully they know what they are doing.

[colin79666]

I'd definitely recommend the Cross Climates, ran a set over 2 winters in Mid/East Lothian and they got me through the Beast From the East! They were quieter than the Yokohamas and didn't compromise the summer handling much if at all.

[200h]

i have to agree wiith colin

i've also used cross climates on my last IS for 2 winters and they where really good in the wet and

the winter months as well as being quiet, dont forget the IS is RWD and i didnt have

a fish tailing back end at any time.

[Tomfromfife]

Thanks for the responses.

Yes, I went for the Crossclimates as I read that Yokohama’s are a hard ride. The low profile Yokohama’s on the car are certainly harsh and noisy.

does anyone know what wheels with part number 4261176140 look like. I can’t find anything on google.

Has anyone carried out any simple sound proofing in the rear of a CT? Other than carrying a duvet in the boot.

[200h]

i have used in the past PU house underlay as it has a tog rating so reduces heat transfer

and it also reduces noise levels best of all its in expensive and you can buy it from any

carpet retailer in the high street.

attached is a data sheet for Pu underlay

 

own_label_8_carpet_underlay.pdf

[Tomfromfife]

Thanks for the info.

I have some good quality underlay so will check the acoustic figure, and maybe double it up with rubber side together.

[refurbished]

Found some info about wheel diameter for certain tyres, all recommended by Lexus:

195/65 R15 = 615mm

205/55 R16 = 596mm

215/45 R17 = 625mm

This makes that we have some differences with mileage and speed shown by the car - a bit higher speed and distance shown when using 205/55 R16.

Also MPG will be a bit better.

Still this does not explain why 15" do better with fuel consumption (as in the 1st post).

I am also using Michelin Cross Climate, 2nd year, and very pleased with.

[Tomfromfife]

Attached screenshots of 17” and 16” wheel spec comparison. 

The new 16” wheels are now fitted. Before I had them swapped I took some decibel readings from the centre of the cabin, at the centre of the back seat. The app I used was SPLnFFT in the apple Store.

I then took the same readings with the new tyres over the same dry roads and I will post the results here later today but first signs show the decibel reading at above 70db with the 17” wheels and 65db with the 16” on average. Watch this space.

[Tomfromfife]

Looks like I used the wrong tyre size in my previous post. The originals were 215/45 R17 not 225 so here’s the new calculations..