Stock X MR (BBS) left front rim. 6000 miles on it, no hard driving. Wheel was just washed, and they don't feel like scratches. It goes all the way around the inside. No other wheel is like it.

If they don't feel like scratches, they're probably some type of deposits...

Try a Mother's aluminum polish on it and see if it dissapears.

maybe tar? who's honestly gonna see the inside of your rim? lol

I wouldn't worry about it too much... If it bothers you just send them to me and Ill send you my GSR wheels!!! LOL

Anyone else think it may have been brake fluid? In which case, you've got a VERY small leak in a line/fitting at the caliper.

Even if they don't feel like scratches, they do look like it in the picture.

It looks like u went through some travel and they got thrown into the inside of the wheel like pebbles in a washing machine.

I can see that... it does look like trails left by a liquid, and water won't do that, especially to one wheel only.

What if you rotated wheels and tried that out for a while and see if you end up with 2 wheels like that?

A few thoughts, use any type of wheels cleaners?

Another thing, I am not sure of the factory finish, sometimes the outside has a clear coat, I don't know about the inside. I would try a little cleaner wax with a soft towel and see if you can buff it out.

focalart is right, many wheels are not cleared on inside...
And acid based wheel cleaners should only be used on cleared surfaces.

Yeap, even with clear coat watch what you use on your rims, use only dish washing liquid and luke warm water! You can take a fine scratch pad and remove those area's, make sure to apply a solid clear coat after words!!!

I agree with the mention of wheel cleaners, but this doesnt address how its only appearing on one wheel.

Is it only on one tire?

There is the chance that some rocks/ pebbles got in and rolled around as one of the other posters said. If it is the insdie only I would not sweat it too much.

According to the OP:

Well I would think that if it was a pebble, there would be either vertical scratches or dings.. These are horizontal.

All I used was car wash soap + water.

They don't feel like scratches, but they do look like it..

What I was thinking (and hoping it's not) is that the rim was cracking or something.. It's the one that seems like it would get the most pressure in a u-turn, and I do a fairly decent amount of those.