Ostragobulus

Really I don't think that many people, including me, are delighted with the spare wheel intruding into the boot so here is my “Mark 2” spare wheel for the RCF. I claim no credit for the idea which is down to our friend Trevor Ruda of Canada who came up with the idea of using an Audi 19” skinny tyre. Actually this is pretty much the only skinny tyre which is available in 19” diameter, certainly in the UK. There are always lots for sale on eBay. The advantages of using this wheel are obvious. The flat boot floor is retained, with both the hard plastic tool holder and the carpet on top. Just as it should be. I have had a wheel adapter custom made which is hub centric with the car and wheel centric with the wheel. The adapter is 30mm thick which ensures clearance of the Lexus wheel studs and of the Brembo calipers. The wheel ends up in about the same position as the regular Lexus wheel when used on the front and a bit further back when used at the rear. In use it feels just as strange as any emergency skinny tyre.

I am in the AA, courtesy of Lexus. I happen to feel more comfortable with a spare than without one. I think that most people, given the option, would elect to have a spare wheel. The LC500 comes with run flat tyres, I believe. Don't get me started on these. I had a BMW 6 Series Grand Coupe where the advertised 100miles range at low speed after a flat, translated to 2 miles and a flat bed recovery!

Bought it on eBay with a 5mm tread tyre. It looks like the front wheel from a 300H or similar.

Here is my take on a spare wheel for the Lexus RCF. Everything can be reversed to "as was". The problem is, of course, the large front brake discs and calipers. To accommodate these a 19” wheel is required and this has to be at least 8.5J or, as in my case, 8.0J with a 5mm spacer. This will not fit under the existing boot floor so a new floor is required. This consists of two shaped pieces made from 18mm plywood. The standard Lexus wheel nuts allow 7 or 8 turns even with a 5mm spacer so this seems to satisfy safety aspects and using the spacer gives around 7mm clearance to the front calipers. All the parts supplied with the car, the foam boot floor insert, the hard flat unit accomodating some tools and the carpet boot floor have been preserved. A 235/40 tyre on a Lexus 8J x 19 alloy wheel with +45 offset is fixed to the boot floor using an M8 threaded rod, with the outside of the wheel facing upwards. A new boot carpet made from two thicknesses of car carpet glued together for greater strength is provided. The wheel protrudes above the standard boot floor level by about 3 inches and until I can think of something better it is covered by a vinyl cover.

I read that too. I have fitted a spare wheel to my RCF and I am just finalising the cosmetics. I will post details in a few days time.

I have now purchased a used, but like new, Lexus 19" wheel tyre size 235/40. This is slightly larger than the 225 size which Lexus fit as this seems to be unavailable or hard to get. The wheel fits easily in the boot and only sticks up by 3" above the floor level. The next step is to construct a new carpeted boot floor with a raised area similar to Big Rat's post. I will report again in due course. In the meantime I wonder if any member is aware of the bolt size and thread for the centre fixing bolt?

Hi Martin F I did not actually put the wheel on the car as it is obvious that it will not fit. The Supra TT wheel will not accommodate the front brake discs and calipers. The wheel needs to be 19", the Supra is 17".

I have reluctantly concluded that a skinny spare is not possible due to the size of the front discs on the RCF. The spare wheel must be 19". Safety issues are obviously paramount and the Audi wheel and adaptor sounds a bit "iffy" plus the fact that an adaptor is likely to cost a lot more than the wheel itself. I have just purchased a full sized used Lexus wheel, size 235/40 19 and I will see what I can do with this. The recommended spare is 225/40 and I guess that I could change the tyre on my full sized spare to gain a bit of storage space, but this hardly seems worth it The pictures submitted by Big Rat signal a possible way forward and I may construct a similar boot floor from plywood and car carpet. I guess the only other alternative is to take the full sized spare in the boot when I don't need the space for other things and otherwise rely on my bottle of Slime and pump! My AA membership, courtesy of Lexus, is a last resort.

I think that the issue with the ISF is the smaller front disc size of 14.2". The RCF is just shy of 15" which seems to disqualify the ISF spare. Has anyone tried this?

Yes I have seen these pictures too. The kit is not available in the UK and the boot space reduction will not be acceptable to most people. It also seems like overkill bearing in mind that the spare would only be used to get home or to a tyre dealer and that we would be driving VERY slowly. The best bet so far seems to be a BMW or Audi 19" steel space saver with an adaptor to convert from 120 to 114 stud spacing. This spare would probably fit under the standard boot floor. I wonder if any member has tried this?

I have just bought my RCF which comes without spare wheel. Rightly or wrongly I am uncomfortable with this. I have read elsewhere that the appropriate skinny spare to get is T155/70d 17 although apparently one has to be careful as many of this size will not clear the front brake calipers. The spare fitted to the Toyota Supra Twin Turbo is recommended as it is said that this has a large enough dish to clear the calipers. I have purchased such a wheel from a breakers yard which I have not yet tried on the car. Before I do I was wondering if any members have experience of this wheel and whether it will be necessary to use a spacer. I should be grateful for any advice.