wheel size and ABS INOP issues
if you go staggered or non staggered larger or smaller tires than stock in the rear, your speedo will be off and need a tune.
if you go staggered or non staggered larger or smaller tires than stock in the rear, your speedo will be off and need a tune.
The issue is what something like: F= 275 40 R17 / R= 295 35 R18?
this is fine and will not trip the abs but if your tire height is different from the stock 275/40/17 which is 25.7" tall, then your speedo will be off and also causing the car to shift incorrectly if it is using speed as a indicator of when to shift.
you could have 22's on there with say a 305/50/22 tire all around, the abs will work but your speedo will be off and the shifts will be off and maybe also other tuning parameters.
The issue is what something like: F= 275 40 R17 / R= 295/35 R18
your specific example will likely not trip the abs nor would it make the tune off much since a 275/40/17 is 25.7" tall and a 295/35/18 is 26.1" tall. the difference is only 1.8% from each other. your rear 295/35/18 is only 1.8% from the stock tune tire size so it would not effect the car much. speedo will read 1.8% slower than it actually is. no big deal in needing a tune.
but if say you run a 275/40/17 front and a 275/40/20 rear, then the abs will not work and your speedo and tune will be off. this is because the 275/40/20 is 28.7" tire tall vs the stock 25.7" tall tire. and they are 10.5% different.
i can't guarantee that the 10% difference is the mark for when the abs gets thrown off but that is what other threads have indicated. i've had tires 8.8% different and the abs was not affected.
this is fine and will not trip the abs but if your tire height is different from the stock 275/40/17 which is 25.7" tall, then your speedo will be off and also causing the car to shift incorrectly if it is using speed as a indicator of when to shift.
you could have 22's on there with say a 305/50/22 tire all around, the abs will work but your speedo will be off and the shifts will be off and maybe also other tuning parameters.
The issue is what something like: F= 275 40 R17 / R= 295/35 R18
your specific example will likely not trip the abs nor would it make the tune off much since a 275/40/17 is 25.7" tall and a 295/35/18 is 26.1" tall. the difference is only 1.8% from each other. your rear 295/35/18 is only 1.8% from the stock tune tire size so it would not effect the car much. speedo will read 1.8% slower than it actually is. no big deal in needing a tune.
but if say you run a 275/40/17 front and a 275/40/20 rear, then the abs will not work and your speedo and tune will be off. this is because the 275/40/20 is 28.7" tire tall vs the stock 25.7" tall tire. and they are 10.5% different.
i can't guarantee that the 10% difference is the mark for when the abs gets thrown off but that is what other threads have indicated. i've had tires 8.8% different and the abs was not affected.


