Space Between Dual Tires

As the vehicle goes over rough surfaces the sidewall bulge in and out on both tires causing them to rub together and that generates heat which will cause the side walls to blow out.

It is important that proper spacing is maintained to allow air flow between them and no touching.

1/4 inch is very close, a spacer would be the cheapest fix, 1/2 inch between tires would be my minimum..

As long as they arent touching. If you find it to be a problem in the future you can always pick up a 1/4 inch spacer to put between the rims. I run them on my dually. If your getting same size i cant imagine there would be a problem man.

down load this handbook and go by your rim size and the tire that you want. At what you stated, if the correct rim then 1.1 inch.
This is big so it will take a few minutes.

http://www.goodyear.com/truck/pdf/2010_engdatabook.pdf

Or, closest point of contact (the bulge just above the tread).

And, are tires properly inflated?

Most tire manufacturers have "minimum dual spacing requirements". Check with your tire manufacturer.

is that 1/4 inch space at the top or were the tires hit the road?