Accord Euro stock rim size.

[racerwannabe]

Stargazer, 225/40/18 is the right size. Thats what most people with 18" wheels are running on including myself. Check your calcs again, the diameter should not have increased by 16mm.

[Stargazer]

Stargazer, 225/40/18 is the right size. Thats what most people with 18" wheels are running on including myself. Check your calcs again, the diameter should not have increased by 16mm.

Sorry, I'm a bit of a noob with tyres. I used the calc on http://www.carbibles.com/tyre_bible_pg2.html

It calculates the circumference of my 205/55/16 to be 1985.17mm and the circumference of the 225/40/18 to be 2001.82mm, a diff of 16.65mm.

The 245/35/18 only gave a 10mm difference (decrease) in circumference. I did notice this tyre size seems to be less popular - some manufacturers don't seem to even make this size. But I do like the thought of having wider tyres too. My mind is boggling at all these numbers and choices! Will the 245/35/18 fit a 18x7.5 wheel?

[Sludge]

Sorry, I'm a bit of a noob with tyres. I used the calc on http://www.carbibles.com/tyre_bible_pg2.html

It calculates the circumference of my 205/55/16 to be 1985.17mm and the circumference of the 225/40/18 to be 2001.82mm, a diff of 16.65mm.

The 245/35/18 only gave a 10mm difference (decrease) in circumference. I did notice this tyre size seems to be less popular - some manufacturers don't seem to even make this size. But I do like the thought of having wider tyres too. My mind is boggling at all these numbers and choices! Will the 245/35/18 fit a 18x7.5 wheel?

You would be pushing it, you really need an 8 inch wheel for a 245. Max on a 7.5 inch would be a 225.

Try this calculator I found it useful when I was looking for wheels.

http://wheelsmaster.com/rt_specs.jsp

[Stargazer]

You would be pushing it, you really need an 8 inch wheel for a 245. Max on a 7.5 inch would be a 225.

Try this calculator I found it useful when I was looking for wheels.

http://wheelsmaster.com/rt_specs.jsp

Thanks. Gave it a go. I should be looking at diameter difference and not circumference? I think that may have been my mistake.
But that above site shows the tire diameter to be 20mm less (and circumference to be 62mm less??).

(Just tried yet another calc at miata.net and it's only 6mm diff... Am I being RTA paranoid about the whole thing?)