[Solved] Space saver specification for C5 X7

[giochel]

I'm looking for a space saver wheel for my 2008 C5 but I can't find any original wheel or the specification. From what I gather, I should have the following:
rim size - 16 inch or larger
bolt pattern - 5x108 mm
centre bore - 65.1 mm. Q1: Is larger ok?
total diameter - as close as possible to 679.3 mm (calculated from the 225/55 R17 full-size). The largest space saver I have found is 115/85 R18 which would give 652.7 mm (96% of the full-size). Q2: would 652.7 mm be good?
offset - Q3: do I need to take care of offset?

Are there any other details I need to take into consideration?

(note that it has to be a space saver, the spare holder now contain the LPG tank).

[GiveMeABreak]

Some have a 16" spare steel wheel, others a space saver Steel wheel and some have the tyre bomb kit and compressor.

Here's one I've found:

https://www.ebay.co.uk/itm/352532320969

[Paul-R]

Would a Peugeot 407 or 508 be a possible source of a suitable wheel?

[giochel]

@GiveMeABreak - that is only 91% of the standard diameter. Seems a bit excessive.
@Paul-R - thanks, I thought of that too, the 508 would come quite close (95%). I just found a 135/80 R17, but no longer on sale.

[giochel]

Ok, so I investigated a bit more and the spare I have found seems to be a Jaguar XE model: https://www.umenlushop.com/index.php?ma ... _id=756426

[giochel]

Update: I bought the wheel, I gained a huge amount of space in the boot, and most details are fine (centre bore, brake space is even better than original, offset seems identical) apart from bolt locking. The original has a conical tapering to tighten the wheel in place, while the Jaguar one has nothing, thus the wheel is tightened by the bolt flange (I'll post a picture). As it is now, I'm pointlessly carrying the spare because I'd be afraid to drive with the wheel tightened like that. I'll look for some heftier bolts, and post the results.

[Paul-R]

I think you'll find that the X7 alloy wheels also use the flat washer for tightening up against. The taper section of the bolt is used for non-alloy spare wheels.

[giochel]

I think you'll find that the X7 alloy wheels also use the flat washer for tightening up against. The taper section of the bolt is used for non-alloy spare wheels.

Hmm... I start to doubt my own memory I remember seeing a conical section deep in the bolt hole of alloy wheel, but I'm not going out in the cold rain to check. I'll look at some pictures on the internet for now.

[Paul-R]

There may be a conical section but the bolt doesn't engage against it.

[giochel]

There may be a conical section but the bolt doesn't engage against it.

You are completely right. I confirm that the conical sections exists on my rims, but that it would be too thin to hold the wheel. The rim is tightened against the bolt washers. Thus I'm satisfied with the setup and should I ever need to use the space saver, I will do it with peace of mind.

[Paul-R]

Excellent. Glad to be of help with your peace of mind.