Just was wondering if switching to a larger rim size would also mean other modifications were necessary. Will my speedometer be off if the overall size of the wheel is larger? By how much? Would it also affect the odometer? And would my mileage suffer?

 

My Loyale seems to be able to accomodate at least a 14" quite easily, with there being a good amount of space in the tirewell. I'm hoping that 15" wouldn't be pushing it.

The size of the wheel is not really important. What is important is the overall outer diameter of the tire you use.

 

Stock diameter is about 23 inches. I have been running 25 inch tires (185-75-14) and it throws everything off by 9-10%

 

If you were to get wheels with low profile tires, nothing will really change.. as long as the overall outer diameter is unchanged.

So basically the tire would have to be thinner. Is there a way to adjust for all this? I would like to have wheels that as a whole fill out the tirewell a bit more and are more proportional to the rest of the car (which the stock ones don't seem to be, IMHO).

i believe there was a thread recently that had tire size adjustments for miatas, oyu tyoe in your current stock tire size and then type the other tires sizes in and it would tell you the overall changes i.e.: 185/70/r14 vs. 225/75/r15 and etc etc. anyone got that, im on diff computer so i cant link it.

 

 

 

 

 

~Josh~

i believe there was a thread recently that had tire size adjustments for miatas, oyu tyoe in your current stock tire size and then type the other tires sizes in and it would tell you the overall changes i.e.: 185/70/r14 vs. 225/75/r15 and etc etc. anyone got that, im on diff computer so i cant link it.

 

 

 

 

 

~Josh~

http://www.miata.net/garage/tirecalc.html , http://www.dsm.org/tools/tiresize.htm

or This one is very good http://www.1010tires.com/TireSizeCalculator.asp?action=submit

Bear in mind that larger rims are heavier, therefore more rolling momentum, therefore brakes are slightly less effective. If you are going to do the 6-lug conversion, consider getting aluminum rims to keep the weight down.

Well, at the moment i have the option of buying some 15 inch aluminium wheels. What would be the best choice of tire if I planned on making the overall wheel/tire size slightly larger without sacrificing a great deal of accuracy? It's hard since I can't seem to visualize the different sizes, but I'm thinking something along the lines of an inch greater in overall diameter. Most important of all, will this affect my odometer reading?

i believe there was a thread recently that had tire size adjustments for miatas, oyu tyoe in your current stock tire size and then type the other tires sizes in and it would tell you the overall changes i.e.: 185/70/r14 vs. 225/75/r15 and etc etc. anyone got that, im on diff computer so i cant link it.

~Josh~

http://www.miata.net/garage/tirecalc.html

 

I use this all the time.

Well, at the moment i have the option of buying some 15 inch aluminium wheels. What would be the best choice of tire if I planned on making the overall wheel/tire size slightly larger without sacrificing a great deal of accuracy? It's hard since I can't seem to visualize the different sizes, but I'm thinking something along the lines of an inch greater in overall diameter. Most important of all, will this affect my odometer reading?

The "best choice" of tire depends on what you intend to use it for, of course, such as street only, 4-season tire, off road tire, etc. If the car isn't lifted, don't get a tire more than about 1" larger than stock, which is about 23" diameter on the stock 13" rims. At 24" you will have no speedo error that matters; speedos tend to be a little optimistic anyway.

 

On 15" rims these might be 50-series tires, and probably there will be only pure street, either 3-season or 4-season. With a lift, you can get into taller tires and have more choices in the 60 and 70-series tires. You would need at least 70-series to find off-road tires, IMHO.

Well, at the moment i have the option of buying some 15 inch aluminium wheels. What would be the best choice of tire if I planned on making the overall wheel/tire size slightly larger without sacrificing a great deal of accuracy? It's hard since I can't seem to visualize the different sizes, but I'm thinking something along the lines of an inch greater in overall diameter. Most important of all, will this affect my odometer reading?

225/50/15 23.8" tall 7+" wide. That's what I'm going to run on my Brat with no lift.