When to rotate tires?

[JimB_FFE]

After 10k miles, I checked the tread depth of my tires. Here's "wear" they are:

Front: .20"
Rear: .28"

At what mileage should I rotate front to back so that both fronts and rears will wear down to .06" at the same time?

Knowns and assumptions:
Depth when new: .30"
Depth to replace: .06" (Should I let them go that far?)
Useable tread: .24"

Wear rate of front: .1" / 10k.
Wear rate of rear: .02" / 10k.

My guess is that it's at 20k miles, when the fronts are down to .1" deep.
At that point, the rears should be at .26" deep.

Swap the tires and I'll scrub .04" more off the fronts and .2" off the rears by 40k miles and they'll both be at .06".

Did I do the math right?

I know the wear is probably not linear over the life of the tires as the sides of the tread blocks are not vertical. But the tire also gets smaller so there are more rotations per mile. Are these effects significant? I'll probably have to revise the numbers as the insides may wear faster.

 

[georgek]

JimB_FFE,

If you're at 10,000 miles, that would be time to bring the car in for your first official "check-up". Ford will rotate the tires , check the fluids, etc.

Last year, Toyota rotated my Prius tires left to right , instead of front to back, causing premature failure. Ever since, I mark one side (front and back), before I take it in.

(Toyota later repaid me for the damaged tires.)

 

[JimB_FFE]

One of the mitigating features that I was hoping would offset the huge premium I paid for an electric car is NOT having to go to the dealer as often as I did with a gas car. I can fill up my own washer fluid and check my own tire pressure.

The goal is to rotate the tires only once during their lifetime. If that's really at 20k miles, that's way better than every 7500 miles for oil changes.

 

[JTCalif]

After 10k miles, I checked the tread depth of my tires. Here's "wear" they are:
Front: .20" / Rear: .28"

At what mileage should I rotate front to back so that both fronts and rears will wear down to .06" at the same time?

Knowns and assumptions:
Depth when new: .30"
Depth to replace: .06" (Should I let them go that far?)
Useable tread: .24"
Wear rate of front: .1" / 10k. / Wear rate of rear: .02" / 10k.
My guess is that it's at 20k miles, when the fronts are down to .1" deep.
At that point, the rears should be at .26" deep.

Swap the tires and I'll scrub .04" more off the fronts and .2" off the rears by 40k miles and they'll both be at .06".

I think the numbers are fair, except my rears wore faster than that.
Just had Ford swap mine front to rear at 22,000 miles.
They measured (after swap) this: rear 3/32, and front 6/32" (about 0.09, and 0.19").
They call 3/32" the limit, so recommend replacement.

(No, have not been carrying loads of cement around, or even passengers often.)
Wouldn't you expect more than 22,000 miles from good tires?

 

[JimB_FFE]

I had mine rotated at 28k miles. They still looked good. Am now at 30k miles. Will measure and report.