Does anyone know if they will fit?

It should give a increase in diameter of about 2,25 cm...

I would not go there, whilst they might fit, they might also rub on parts of the car that you can't see, they will change your gearing, they will make your speedo mis-read and probably the most important, they will almost certianly void your insurance,

A 2cm increase in diameter is a lot of speedo error to factor in, they may well rub on the wheel arch when you have passengers.

Use this web to calculate differences between old and new size. http://www.miata.net/garage/tirecalc.html

Is this instead of a 40 profile? If so, be aware there was a bit of an issue with the elk test and the 40 profile rolling off a loaded front wheel. So a taller profile might not be a great idea.

Edited 22 January, 201214 yr by davekmoore

This issue has become an urban legend. Fact is that they used more than the specified weight and lower tyre pressure than specified.

This issue has become an urban legend. Fact is that they used more than the specified weight and lower tyre pressure than specified.

Yup, we all know all of that by now. But would you knowingly go a higher profile than the one that failed that extreme test?

Yup, we all know all of that by now. But would you knowingly go a higher profile than the one that failed that extreme test?

Hmmm.. I may be stupid, but the 16 and 17 inch wheels have a higher profile as standard...??

A 2cm increase in diameter is a lot of speedo error to factor in, they may well rub on the wheel arch when you have passengers.

72.4MPH when the speedo reads 70MPH is hardly a lot.

Don't forget the 22mm larger diameter will mean the tyre runs just 11mm closer to everything this may be OK.

What is your reasoning for using a 45 profile tyre anyway? they are not as common a size so generally tend to be dearer than a 40 series tyre.

Yup, we all know all of that by now. But would you knowingly go a higher profile than the one that failed that extreme test?

Eeerrr yes, because as previously said the tyre failed the test because the tyres were overloaded AND under inflated, this is why they failed the test.

Eeerrr yes, because as previously said the tyre failed the test because the tyres were overloaded AND under inflated, this is why they failed the test.

No worries. You're just braver than me.