instead of replacing all of the tires i spent the extra money ( saved by not buying a new spare ) to upgrade the load carrying tires an extra size and an extra load rating .
i picked up an extra 35 % in load rating capacity in pounds as stated on the tire sidewall . minimal cost while replacing .
i did this because i occasionally tow long distances starting at 5 pm and towing through the night . i do not want to change a tire in the dark .
i sometimes do this both directions to really far destinations .
i probably pick up an extra mpg or so due to no traffic and i certainly can average a couple of mph better also even at the same cruise setting .
we don't have a freeway in central oregon and it is mostly 2 lane US highways such as hiway 97 , 20 , 26 , and so forth .
