help with tyres and wheels please

Hi everyone

Not long bought a 94 NA, but looking for some advice on tyres and wheels please, hopefully some of you will have more technical knowhow on this than me:

The wheels are

http://www.rimstock.co.uk/rimstockuk/wheelrange.php

model: Team Dynamics Diablo

Fronts are 18 inch 7.5JxH2 with 215/40 tyres

Rears are 18 inch 8.5xH2 with 235/40 tyres

Now the Team Dynamics website fitment guide suggests a tyre size of 225/40 for both sizes of wheel.

Right questions are:

What is the standard trye/wheel size to give the correct speedo reading?

What is the largest (width) and most suitable tyre size for each wheel?

I am unsure where the speedo calculates from but I assume that it is the rear and so the tyres at the back should be as close to the original revoultion distance as possible?

If i have 18 inch wheels, surely the spare is no good to me as is a completely different diameter?

Thanks all hopefully see a few of you about soon - I am Guildford, Surrey way.

Cheers

:-)

Wightlad

even though it's an N/A i would want more width on the back, i think standard they are 245 on rear and 215 on from

but i'm probably talking out me ass

ps i have a loverly set of 18's for sale 265's on rear

215 on the front?!

That's narrower than stock. You'll be in big trouble with you insurance company if you have a claim while running undersized tyres and wheels.

Edit to add:

Stock size for an NA is 225/50/16 front and rear

probably talking out me ass

looks like i was then lol

i didn't know they were the same sizes front and rear on NA

IIRC some NAs had 225/50/16 front and rear but some had 245/45/16 on the rear.

And some had 17" wheels of course.

None of them had little 7.5" front wheels or 215 tyres though.

It would probably drive very nicely on the smaller width rims, 215 and 235 would be a good choice, IMO. Team Dynamics do some failry lightweight rims, in the motorsport range, with a good choice of offsets, I am thinking of a set for wet tyres for my Skyline.

I'm sure you're right Chris but with regards to insurance it's risky. I wouldn't want to give them any reason to refuse payment in the event of a claim.

225/40 18 front

and 245/35 18 or 255/35 18 rear

Will be close to stock diameters etc.

Hi guys well after much searching I have found this which proves quite helpful

http://www.rochfordtyres.co.uk/tyrecalc.asp

:-)

Thanks for your answers although some are a little off track!

Many thanks to Merckx, short sweet and to the point, just what I was looking for.

Hi guys well after much searching I have found this which proves quite helpful

 

http://www.rochfordtyres.co.uk/tyrecalc.asp

 

:-)

I used a similar one.

This is helpful aswell, from someone on Supraforums.

You can input the wheel widths, offsets etc!

Supra Tyre fitment.xls