Anyone know which of these numbers is offset? (And how to measure offset manually)

['19Sport6Man]

Just picked up a set, ordered 17x9 supposed to be +40 offset

but the way the wheels are stamped can’t tell if they are 40 or 45

 

['19Sport6Man]

Guess everyone finds the wheel marking confusing

 

[Discount Tire]

Just picked up a set, ordered 17x9 supposed to be +40 offset

but the way the wheels are stamped can’t tell if they are 40 or 45

Just as it suggests, the inset of the wheel is 45mm and the offset is 40mm.

 

['19Sport6Man]

Just as it suggests, the inset of the wheel is 45mm and the offset is 40mm.

Thanks for the reply and link - having a hard time following though

If the mounting face is 45 mm INSIDE (towards car) of wheel centerline, how can it ALSO be 40 mm OUTSIDE (toward face of wheel) of wheel centerline?

Isn’t that saying that a wheel has a negative offset of 45, AND a positive offset of 40?

 

[arpypat]

Those are 17x9 +40 wheels.

You can see the "Inset 45" is closer to outside of the wheel and the "40" is closer to where the machined mounting surface is.

I'm guessing these are Enkei TS5 wheel? They also make 17x9 wheels for 5x110 bolt pattern but with +45 offset. I'm guessing the wheels look the same at some point in the manufacturing process, but that "40" would get machined off when these end up as 17x9 + 45 wheels.

 

['19Sport6Man]

Those are 17x9 +40 wheels.

You can see the "Inset 45" is closer to outside of the wheel and the "40" is closer to where the machined mounting surface is.

I'm guessing these are Enkei TS5 wheel? They also make 17x9 wheels for 5x110 bolt pattern but with +45 offset. I'm guessing the wheels look the same at some point in the manufacturing process, but that "40" would get machined off when these end up as 17x9 + 45 wheels.

Thanks Pat - that makes sense.

you guessed correctly on the wheels too.

 

['19Sport6Man]

Used this helpful video to measure the offset manually, and they are indeed +40

 

['19Sport6Man]

Full width of wheel with mounted tire is 260mm (the thickness of the metal ruler is 3mm), so half is 130mm.

The measurement from floor (face of wheel) to mounting surface is 170mm.

The difference is 40mm.

Offset is +40

 

['19Sport6Man]

Double checking by measuring from mounting surface.

90mm from floor or face of wheel (this smaller straight edge that fits inside wheel is also thinner - about 1.5-2mm thick).

So 130mm (centerline of wheel/tire) minus 90mm = 40mm.

Offset confirmed at +40