Listed in your owner's manual and on the driver's door post.
Can I use 245 70 16 in an 2003 tahoe
NO
235x55R16
A 1997 Mercury Sable came stock with size p205/65r15 tires. Taller or shorter tires will cause the speedometer to read incorrectly.
Are 235/85r/16 compatible with 1996 Chevy tahoe
That would be the 4L60E transmission and 1996 and 1997 are the ONLY 2 years that will fit that truck.
On a 1997 Mercury Villager open the drivers door and on the latch pillar you will see an information sticker that shows the original size tires on the vehicle from the factory
Tire size is: 185/65R14
Group size 34/78 800 CCA will work fine.
If you open the drivers door and look at the inside of the door jam you will see a sticker that will have the FACTORY tire size written on it.
tire size for 97 venture is P215-75R-15
mine has 16 inch