Lewis Hamilton Posts Shirtless Selfie, Ready For Race Week!

It's not hard to understand why Kim Kardashian's dating Lewis Hamilton -- the Ferrari superstar popped his top for a shirtless selfie ... and it's got hearts racing.

Sir Lewis shared the photo on his Instagram page Tuesday night ... showing him only rocking a pair of Lululemon shorts as he stood in front of a mirror.

Hamilton's tatted bod was on full display ... and he looks ready to hop behind the wheel when the Formula One season kicks off in a matter of days.

"Race week!" Hamilton said. "I'm ready."

Hamilton made the most of his free time before this weekend's Australian Grand Prix -- as we previously reported, he spent the weekend with Kim at Lake Powell ... staying at Amangiri, a super-lowkey resort in Utah.

The seven-time champion will now be pretty busy with his day job -- the F1 season goes until December ... with a few breaks in between.

Now the real question is -- will Kim be in the Ferrari garage Down Under?? After all, big names always roll through for races.

As for the selfie ... it goes to show the two lovebirds have something in common -- 'cause we all know Kim loves her mirror selfies.