Hi there, I have a standard Mk1 MX5 with 55k on the clock. Saw a beautiful black MX5 with what looked like bigger Minilite style wheels on in the STHT mag a few issues back, and drooled! What’s the score with fitting aftermarket wheels and tires? What sizes are OK to run happily? Did you see the article in question? Anyone know the chap who had this car? Seemed to remember the photo showed him parked up by roadside with his brother, who also owned a black MX5.
Cheers, Tim
You need to pay attention to stub pattern (4 studs, PCD 100), bore diameter (54mm I think, but check on that), off set (standard is ET 45mm. As the number reduces, the wheels move out relative to the body. This will affect handling; at one point, the wheels may foul on the bodywork. 45-25mm is generally considered to be ok without causing bodywork problems.
You were probably looking at a 15" wheel; they will come, generally, in widths 6.5-8". 8" can look a bit big, unless you add wheelarch blisters.
Minilite wheels; there’s Minilite (£150-200 per wheel), Rota (the RB and the RK-R); which are Phillipino copies of the Minilite/Watanabe style (£120ish per wheel), Watanabe (Japanese licenced copy of the Minilite, £2-300 each new, can be brought used for £300-400 for a corroded set), Panasport (another Japanese wheel, they were £200-250 each from Moss), Midland Wheels (heavy copy, not sure they come in Mazda specific stud profiles, but they are cheap). Weight; factory wheel is only 12lbs or so, which is very light. Most typical aftermarket 15" wheels are 14-16lbs each; I can notice the difference when these are fitted. Avoid the really heavy wheels.
That’s really helpful, thanks. You know your wheels!
And if anyone has any interesting alloys (that fit!) to sell me, drop me a reply. Thanks again.
Rota RB
Rota RK-R
Chaparral
Watanabe F8
Panasport
UK-sourced KN Minatour (Moss used to sell this)
14" Watanabe, with the suspension deliberately jacked up
15"WAtanabe with suspension back to a lower setting
Wow! Rota RK-R gotta be my favourite. Want 
The disappointing aspect of the RK-Rs is that [1] they’re heavy @over 16lbs a corner [2] stupid offset/weight, so they will either turn a standard car into something looking like a clown car, or condemn a lowered car into continual smashing on the wings. The RBs are an ok weight, and can be had, with some effort, in a small range of different offsets. The Watanabes and Minilites can be ordered in a wide range of offsets and widths.
So Rotas are copies of Watanabes which are copies of Minilites. Howabout Thai copies of a Rota of a Watanabe of a Minilite. From K.Speed, which I think is a brand name used by one of the cheaper Asian wheels:
Blatant:
Even the advertising:
And in Indonesia:
Scarey (note one of the spokes…):
These wheels are all fakes.
Genuine Watanabe logo (note which way the Cranes face):
Loads of examples of different Wats here:
http://www.rs-watanabe.co.jp/userspage_new/mazda.htm
14", different widths/offset
15"
There are also the much more rare 15" Watanabe Speed-Star RS-8
split-rims, here are some I have just re-furbished, I do know for a set of them available for sale currently, PM me if you are interested
I was going to sell mine but since refurbing them (satin black and hand polished) Mrs. Eunos has forbade them going elsewhere and insisted they now go on our supercharged Eunos R2-Limited - so thats her birthday present taken care off then…
Not that rare, judging by the number of times these SSR Wats come up for sale. I sold a similar set of these SSR Wats for £60 not so long ago. Some have had the rims welded up in Japan, some haven’t; it seems the seams could leak. They were originally intended to be 3-piece, but it looks like someone decided they should be 2 piece instead. These were made for SSR when Watanabe was facing bankruptcy. The one’s I had had been assembled with stretch bolts; replacements can still be had from SSR, but pricey. Others were put together with fairly normal bolts, but all the ones I’ve seen look so banjaxed, that I’d get replacements if refurbishing the wheel (which is pretty normal in the BBS world). They seemed an awful lot heavier that the cast 15" F8F Wats I had on the '92 car. Not as heavy as Panasports though (which Mazda opted for as an OE supplier).
I’d plump for the real 1-piece Watanabes if you see them, not the SSR versions.
XXR (Sportmaxx) 513s are the other cheaper variant of the Minilite style; like the RK-R, stupid offsets and widths, but the price is good at <£100 per wheel, and decent finish.
Unusually (for a minilite “banana” spoke wheel), they are multi-fitment.
Trouble with the cast Watanabes is that this can happen, I would prefer the rim to bend rather than crack…
Mine are still 3 piece and do not leak at all 
I sold a set of 14" Split-Rim Watanabes for over £250 recently after buying them off a simpleton for £40 and a handful of magic beans for the set.