Suspension settings can be whatever works best for you. Although in front of me I have the Mazda Performance Handbook and that gives settings for street as toe in
  front rear
camber -0.5 to -0.75deg -0.75 to -1.0deg
caster more than 5deg
  1/16" 1/16"
(12/99)

4 wheel alignment
The MX5 is fully adjustable in 5 ways. The factory setting below are pretty wide and if you like your car set up consistently and value your tyres you will get this done at least once and maybe even every year a big pot hole can push the whole lot out. These settings are standard ride height you cannot get some of them with lowered cars. I use Miq Millmans settings; http://www.miata.net/garage/align.html - also a good start if this is all a bit confusing print it out and take it to the garage so you understand them. I also set this up with 75kg of cement bags in the driver's seat as this is how I would be normally driving a bit extreme but hey if you have it why waste it.

Specification figures from Mazda manual spec ('94 Miata);

 

Front Ride height Caster (+/-45' )
328-337mm 5d 16'
338-347mm 5d 02'
348-357mm 4d 49'
358-367mm 4d 35'
368-377mm 4d 21'
   
Front Ride height Camber (+/-45' )
328-337mm -0d 20'
338-347mm 0d 03'
348-357mm 0d 24'
358-367mm 0d 44'
368-377mm 1d 02'
   
Toe-in per side = 0d 09' +/-09'  
   
Rear Ride height Camber (+/-30' )
346-355mm -1d 08'
356-365mm -0d 54'
366-375mm -0d 43'
376-385mm -0d 35'
386-395mm -0d 30'
   
Rear toe per side 0d 09' +/- 09'  

Remember there are 60 minutes (that is what the { '} mark is for) in a degree.

But the real answer is to go and then be armed to deal with the alignment people... and find one that actually know what they are doing .. very rare outside race preparation shops.. I end up using a tape measure to check the toe in/out alignment to prove it was wrong on my first alignment.

Settings on my '94 Eunos FM2 ... with FM springs (25mm lower) .. attempting to get Miq Millman settings

front camber -1.14 -1.12
front castor 5.29 5.47
front toe 0.01 -0.01
0.13 set back    
0.02 set back ... he did not know what this was either .. presume axle to axle alignment
rear camber -1.86 -2.25
rear toe 0.23 0.27
(12/99)
Since the Miq Millman alignment settings were originally designed for a Mk1, are they still applicable to a Mk ll which has a slightly different settings to start with, and particularly a 10AE which also has different damper settings ? (2/00)
Quite a few people have tried the Miata.net alignment suggestions on the Mk2, and until now, I have only read positive reviews. No personal experience, though. (2/00)
IIRC the Miq alignment has toe-out at the front. From personal experience I can say that this gives the car a very twitchy feel - horrid for road use. Try a little toe-in at the front - it worked for me. (3/00)
Anyone remember the OEM wheel offset for MK2 alloys? (2/00)
40mm for the 15" wheels. (2/00)
Oddly enough I wrote to Mazda UK about this. Their reply:
45mm for 14" wheels
40mm for 15" wheels (2/00)

40mm offset (mk1 had 45mm)
100*4 PCD (hole position)
54.1mm centre hole (or get the correct centering ring)

If you go for a wider wheel than 7", I would recommend reducing the offset to 30mm for 8" to prevent inner wing rub (2/00)
Sorry if I am being painfully stupid, but although I know what you mean by wheel offset, what are the consequences of using wheels with an incorrect offset? also, is this a linear relationship ie: 45mm for 14" wheels, 40mm for 15" wheels, so would it be 35mm for 16", 30mm for 17" etc. (2/00)
I believe the answer is "Yes" but in relationship to the width of the wheel, rather than the diameter. It's probably been expressed (or more accurately, implied) that way as the wheel width generally increase with diameter. Does that make sense...!? (2/00)
Sorry....answers to first part include possible contact (bodywork/brakes??) and poor handling/tracking IIRC somebody mentioned (on another list) possible extra stress on bearings also. (2/00)
Just another bit of info, there is also a chart on miata.net under the garage and then to wheels and suspension, which gives the wheel weights, offsets of all stock wheels used and a great many aftermarket wheels as well. I found it very helpful in considering new wheels. (2/00)

The offset is purely a feature of the wheel design - where the designer decided to place the centre part (and the hub fixing face) laterally in relation to the centre of the rim width.

Wheels with a bigger offset look sexier, because they look wider (deeper) when you look at them from the side.

Changing the offset theoretically changes the suspension geometry, and can affect the handling.

Probably the effect is slight with most wheels sold as suitable for the MX5 - and probably not noticeable. The bigger problem with wheels is weight. Standard MX5 wheels are very light, and the unsprung weight in each wheel is low. Virtually any aftermarket wheel is much heavier than those fitted as standard, and the effect is worse the bigger the wheel. The bigger the unsprung weight, the more unpredictable is the handling on bumpy corners. (2/00)
This is interesting, especially the fact that my OEM wheels are 4-5lbs lighter than most of the aftermarket stuff. On such a light car I would be loathe to increase the unsprung weight by such a large amount. Those early BBS wheels look appealing, weightwise... (2/00)
Having recently lowered the 5, we now need to get the alignment done. I have the settings from Miata Net, but the garage have asked me how the adjustment is done - are there shims involved or is it a straight forward bolt adjustment? We are going for the Miq's settings - unless you know better :) (5/00)
Find another garage that knows about mx-5s in that case It just done by losening the innner pivot bolts on the wishbones, and turning cams, then locking up again. (5/00)

Wheel alignment adjust bolt and camplate, part no as follows

Bolt = NA01-28-4A0
Camplate = NA01-28-473
Nut = B037-28-091
These numbers are for the rear & cars up to April 96 (1/01)

If those part no's are not recognized then use the following no's
Bolt = NA80-28-66Z
Camplate = NA80-28-473
Nut = B001-39037B

if you use these no's you must buy all three items because they are a standardised part & are different to the original ones i.e. your old camplate & nut will not fit the bolt listed above. (1/01)
Just had my roadster suspension overhauled and going to have a 4 wheel alignment done but all the advice on toe-in is in inches - anybody know how to convert one to the other? and (probably a stupid question) is 0 degrees and 30 minutes equal to 0.5 degrees? (4/01)
Not sure about the inch to degree conversion but you are correct with the 0 degree 30 min being 0.5 degrees from what I can remember :) (4/01)
1mm = 0.040 ins (approx) = 0deg 06min = 0.1deg toe in. So 0.5 deg = 0deg 30 mins and is probably too much for a lively feel - spec is 0 deg 18min +/- 0deg 18min - the more toe in the deader it feels. (4/01)
Careful with alignment, I've just had mine adjusted (just the toe due to excessive outer edge tyre wear) and it was set at the recommended amount of 1mm per side. I had it adjusted to zero and the handling was awful (IMHO), Masses of *thinks really hard to make sure he gets this right* oversteer... I took it back and got it changed to 0.5mm per side and it's wonderful. Hopefully more even tyre wear too... (4/01)
After all this alligment talk I would like to add a further suggestion. If this is not your 1st allignment, and maybe if the suspension has been apart before for bushes/shocks etc, then I thoroughly recommend getting new adjuster bolts and nuts. Where can I get these? (6/01)
Mazda dealer. NAY9-28-6AZ These are the better ones. You need eight. (6/01)
Don't know anything about these technical things, but a lot of people follow this Lanny Chambers' advice apparently: http://www.hummingbirds.net/alignment.html (7/01)
Word file with Mk2 settings. (1/03)