Bigger Wheels on 460

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Jdring
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Joined: 12.04.2004
Location: South of Oxford, UK. 'dingaling' on the Register
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I got a nice set of 265/60 R18 wheels (from a G350 I think) and want to try them first on my 460.

Will I need spacers and longer wheel bolts to prevent rubbing/contact on the inner sides?

Obviously no electronics or ESP to worry about, and the slightly bigger circumference may add a little bit of top-speed for a more comfortable 3k rpm running.

I thought I would calculate that and to start there is a good explanation of Tyre Size standard here:

https://www.uniroyal-tyres.com/car/tyre-guide/tyre-knowledge/what-does-tyre-size-mean 

So the circumference of my current 460 wheels (225/R75 R16) would be:

75% x 225 = 169mm.  Plus half the rim diameter = R16 / 2 * 25.4 = 203mm.   168+203 = 372mm Radius (744mm diameter)

Interestingly, measured diameter with a tape and it was about 720mm, so close !

For the new tyre (265/60 R18):

60% x 265 = 159mm.  Redius = R18 / 2 x 25.4 = 229mm.  159 + 229 = 388mm  (775mm diameter)

Measured at 750mm, so the same undermeasurement.

 

Lets go with the calculated diameters:

1 wheel revolution = Pi x Diameter = 3.1416 x 744 = 2.34m  (for the 460 wheel)

1 wheel revolution = 3.1416 x 775 = 2.43m  (for the 463 wheels) - not that different

2.43/2.34 = +3.8%  per revolution.

Now the guessing part... I recall that the 460 does about 3,800rpm at 60mph currently.  So with the 3.8% increase in wheel, that will increase to 62.28mph.

So after all that... bugger all noticeable increase!

 

Anyway - they will look nice - anyone got wheel spacers and bolts?   

 

G-Restorations
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Joined: 07.04.2011
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Re: Bigger Wheels on 460
Hello John I've been running these wheels on my 460 for the last 6 years. To get the same offset as the original wheels you will need 20mm spacers. This will put no more load on your wheel bearings than the original wheels as the Centreline if the wheel is the same. So that the wheels lined up with the 463 arches I'd fitted I used 40mm spacers. This isn't ideal the wheel bearings needed regular adjustment and puddle steer was a bit scary Saying that though the handling was really improved. I'd really recommend continental 4x4 LX tyres. Gordon