The 5.5J and 6J are the width of the wheel rim in inches. You also need to look at the ET, the offset. Ford standard for the Mk2 Fiesta is ET35, you can vary it a bit though. But the wider you go on the rims the more important the actual offset becomes.
Make sure the new rims are specifically for the Mk1/Mk2 Fiesta, after that Ford switched from wheel bolts to wheel nuts. The bolts had a smaller seat size so if you use the later wheels with the earlier bolts there is hardly anything holding the wheels on and the bolts can pull through the wheels. You can get round this by using special larger bolts or adaptor washers that fit under the existing bolts. From: 'Martin Hodnett' via Quantum Owners Group Sent: Wednesday, July 11, 2018 1:03 PM To: Quantum Owners Group Subject: [Quantum Owners] Re: 2+2 Alloy wheels Grateful for the comments left, I forgot to say that the rims are 13" diameter currently fitted with 165x70x13 tyres (not one of which is the same as the others). I've been looking at WheelBase for alternatives. Not sure what 5.5J and 6J means but if I do replace the wheels I think it will be with 14" rims and 185x55x14 tyres, they should fit within the wheel arches and not foul suspension struts or body. Thanks for your help! Martin -- -- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To post to this group, send email to quantumowners@googlegroups.com To unsubscribe from this group, send email to quantumowners-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/quantumowners?hl=en IMPORTANT NOTE: All information presented herewith is provided on an "As Is" basis, without warranty or the implication thereof. Neither the Quantum Owners Club nor the individuals associated with the Quantum Owners Club or in the preparation of the above information shall have any liability to any person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the instructions contained within this or related message(s). --- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to quantumowners+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- -- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To post to this group, send email to quantumowners@googlegroups.com To unsubscribe from this group, send email to quantumowners-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/quantumowners?hl=en IMPORTANT NOTE: All information presented herewith is provided on an "As Is" basis, without warranty or the implication thereof. Neither the Quantum Owners Club nor the individuals associated with the Quantum Owners Club or in the preparation of the above information shall have any liability to any person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the instructions contained within this or related message(s). --- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to quantumowners+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.