My 2008 Grand Caravan has 225/65R16 tires on it. Can I replace with 225/70R16 tires? They are only 1 inch larger in diameter, all other measurements are the same.

 

You can, because the specified tires for this model are 225/65-16 or 225/65-17. The OE optional 17's are exactly 1" taller than your originals too.

A 70 series is generally narrower section width than a 65 when both tires are 225, so all other measurements would not be identical. The tread should be narrower. The 65 series is used to improve handling over 70 series. Premium name brand tires like Firestone's in the correct size are sold at tirerack for under $90 each. The total cost for a set of 4 comes to $360 plus $50 for mounting plus $50 shipping = $460. I'm guessing you're trying to buy tires locally at a place that only stocks a few sizes, so you're likely gonna pay more for the wrong tire size and they will likely wear out faster and handle poorly.

PS: I plan to run 215/70-16's in the winter to reduce width and increase traction. They are closer to the correct height.