Nearly all sites selling spare "kits" on quote PCD as 5x100, but it's definitely 5x112 (on UK MG5's anyway). Some folks are using an audi/ mark v golf spacesaver, but I've found one that's very close to the diameter of the official spare. I've just test fitted a Merc Class A/B spacesaver ( at rear ) with T125/90/R16 PCD:5x112 CB:68. ET32 The diameter is 24.84inches. The diameter of the full size MG5 original (205/60/R16) is 25.67inches. So only .83inches difference. Just got back from a mile test drive at 50mph. No vibration, no errors. Plenty clearance for hub & calipers. Nothing rubbing. Got the merc spacesaver for £60 including a really nice merc jack and wheel wrench. ( a bit nicer than £250 from dealer ). All fits in the boot perfectly along with the gunkpump. Have set aside the original expanded foam insert. I may buy a spigot ring for extra security ( 68.1->56.1). Hopefully I'll never have to use the spacesaver, but will have peace of mind knowing it's there. Could have bought the dealer version with a nice foam insert for £250. But that's no fun. And I've saved £190.