Tire Question for 2002 Journey DL

[rhigg1959]

I have Michelin 235/80R 22.5 tires that have date codes of 2011 and showing signs of cracking on the sidewalls. I priced new Michelins but price was $450.00 per tire not using the FMCA discount. I also price Continental 255/70R 22.5's at $350.00. Is there an issue using the Conti size vs the Michelin size. I only have these two truck tire dealers to work with here.

[NMBluept]

The Continental's are ~0.8" smaller in diameter. The smaller diameter will introduce a small speedo error, in this case about 2% (1.2mph @ 60mph). Make sure the Continental's have the same or higher load rating as the Michelin's. Also need to consider the Continental's are about 3/4" wider.

Tire diameter calculation: (235/80R 22.5)
What the numbers mean: 1st number is tire width in millimeters, 2nd number is aspect ratio of tire height to width (percentage), 3rd number is wheel diameter.
So:
Sidewall width divided by 25.4 (convert millimeters to inches)
Tire height = Sidewall width multiplied by aspect ratio (80 = 80% or 0.8, 70 = 70% or 0.7)
Tire diameter = tire height times 2 plus wheel diameter (TH * 2 + 22.5).
Tire circumference = diameter * pi (3.142)
Revolutions per mile:
Convert tire circumference to feet by dividing by 12
Divide 5280' (number of feet in a mile) by tire circumference

Good luck with your decision,

[rhigg1959]

Thank you for the reply. Tuff decision. I don't mind paying more if the Michelin's are worth the price, but from what I'm reading, the sidewalls dry rot fast.