Tire Sizes Outdated G78-14

[EMC 1810SS]

I am going to replace my trailer tires and have realized it is cheaper to order new tires and rims online than to have new tires put on my rims. I know that a G78-14 is about equal to a 215/75D14. But then I got to thinking, what about a 15" rim? How would a 205/75D15 Total diameter compare to the G78-14? or should I just save myself some drama and order 14" tires?

 

[Socal Pat]

Re: Tire Sizes Outdated G78-14

The difference between the 2 you mention is only like .3". The rolling circumference is 83.9" vs 85.2" or only 11 revs per mile. Very close. The good thing about changing to a 15" wheel is your tire selection goes way up. Here is a calculator you can use. http://www.miata.net/garage/tirecalc.html