mini tyre sizes needed for mx5 mk2. IVA speedo check.

[john]

My donor is a mk2 1999 and came with 195/50/15 on a 6j wheel.

I've bought some mini one 2007 steel wheels, the tyres on these are 175/65/15 and rims a 5.5j so I know the rolling radius is out and can't use for IVA 

Two options I thought of were can you run the correct Mazda 195/50/15 on these and fit/look ok?

Plan B was doing some digging into other sizes and I think the following adds up;

175/55/15 is + 0.44 so 30mph/60mph are 30.1mph/60.2
185/50/15 is 1.77 so reads 30.5mph/61.06mph 
These are the two closest I could find when comparing the sizes.

Any advice for the IVA about the above or what have others used/used 195/50/15 on a 5.5" wheel?

[gwnwar]

check this
www.tacomaworld.com/tirecalc?tires=195-50r15-175-65r15

www.carbibles.com/tyre_size_calculators.html

[stevednorris]

I'm going to use my MX5 donor wheels and tyres for the IVA test then plan on changing them at a later date if they don't look right.

[john]

Stevednorris - Wish I had kept mine now but in my ignorance hadn't thought that far ahead mate, for some reason I hadn't realized iva did speedo calibration as part of the test (I admit its a good thing I just didn't know they did it) my mini wheels have new Michelin tyres on but slightly over read so need to plan my options.

Gwnwar - thanks for the sites I used them to double check, looks like I'd found the closest two options but do we know if the OE size fits on a 5.5j ? Some googling gives a mixed bag.

[stevednorris]

It might be worth speaking to Stuart at MEV, I'm pretty sure he got his Replicar through IVA with wire wheels and 195/65/15 tyres on and it passed (just). So you should be fine with 175/65/15 tyres.