Tires: Tire size, class c rv, wheel spacing

Question
Barry,
I have a 1986 Class C RV on a Ford E-350 chassis, when I bought it it had LT215/85-16 tires on it with a dual rear wheel set up. My question is....Can I change the tire size from 215/85 to 235/85. The height is no problem (inside the fenders).

Answer
Don,

You probably can't be able to make the change - but here's how to tell:  The dual wheel spacing - that is the distance between the centerline of one dualled tire to its partner on the same side.

For an LT235/85R16 to fit, the spacing has to be at least 10 3/4".

Ya' see, most of the time, the vehicle manufacturers set up their dualled vehicles with just a bit more than the required dual spacing - and in this case an LT215/85R16 requires 9.9" - so they would use something like 10" or 10 1/4".  But I can't be sure because I don't know how this works for all the possible chassis's out there.

So measure the dual spacing and you'll have your answer.