Tread depth difference between front tires

[FireFox31]

What's the maximum allowable difference in tread depth between left and right front tires on a 2000 V70 FWD N/A automatic? Is a 1.5/32" difference acceptable?

I did a thorough check of the tread wear on Geronimo. The front left tire measures 4.5/32" on its inner and outer edges and 6/32" in the center. The front right measures 3.5/32" on its inner and outer edges and 4.5/32" in the center. That 1/32" to 1.5/32" difference is more than I've ever seen on my cars.

Are the different sizes causing the two front wheels to spin at rates different enough to cause other problems?

When driving, the speedometer jerks between a few MPH, uncertain about how fast the car is going. This may be from the rusted reluctor rings which are causing the (rebuilt) ABS module to trigger constantly. Or could it be the wheel sizes spinning at different rates?

After a 30 minute drive, both front wheels got hot. This is likely from the front right wheel hub which is totally, generating heat from friction. But how could that make the other wheel hot? Could the transmission be strained and heating from the different wheel sizes?

Your input will help me decide if I must replace both front tires or if the 1.5/32" difference is acceptable. Thanks.

[abscate]

1/32 of an inch is 0.8mm, tires are about 500mm across or so?

Even finicky bmw allows 1% variation in tire size on Xdrive , so you are about 5x below that standard

I would guess bad tone rings are the source of the speedometer fluctuation.

I’ll dig and see if there is a Volvo spec on tire size variation

[abscate]

Addition.

No Volvo spec others than Volvo makes no recommendation on tire rotation, as in “ we make no recommendation “

BMW X drive spec is 2 mm for tread difference

I would worry more about your caliper paint. Green for starboard , red for port. Swap when coming home overseas

(nautical humour)