The second number is not exactly the height of the tire, but the percentage of the width of the tire that is the height of the sidewall. So a 235 45 = 235 * .45 = 105.75mm sidewall. A 255 40 = 255 * .4 = 102mm sidewall. 3.75mm smaller, so 7.5mm smaller tire overall. Doesn't seem like a lot, but on the evo if you ran different sizes like that front and rear, you'd be buying a new transfer case.

You've never put 33" tires onto a 4 cylinder Ranger (or some truck) and had the owner complain about it being gutless now or that the speedo was off?

Not here to argue with you, but the math is there and it doesn't lie!

 

+1, goofygrin's math is dead on...

I've run 255/40/17 and 255/40/18s and not had too much of an issue. I did however, have to trim the rear fenders so that the 18s wouldn't rub.

 

hey booster9, i've got a few sets of wheels/tires i needed switched before tuesday, PM me or text me if we can get it done

 

man i never noticed that, but its such a tiny difference that you probly wouldnt even realize it.
and unfortunatly i have put 33" tires on a ranger, also had some swap in it and it was his mudding car??, the thing was slow as *****, but he never said anything about the speedo

 

To totally derail this thread you can put the 5l from a mustang or explorer into a ranger. Faster and better mpg.

 

lol i guess thats what it was, but it had hugeee tires.. it was def the biggest tires ive ever done

 

Okay, just got my new Yokohama AVIDs in the mail today. I am in my mind comparing them to the old Nexen 3000s I was running. They were both 205/40/17s, but the side wall on the Yokohomas seems smaller. Is this possible?

 

You can't compare tires off the wheel really. Now some tires are definitely wider than others in the same nominal width (star specs and toyos).