remvoing oil and grease stains in on a concrete floor

[BigShrimpin]

Can anyone recommend a good product or process for removing grease/oil stains in concrete driveway or garage floor? I've got a few good ones that I have to remove from these motors.

[Mr. Demeanor]

Brake cleaner.

[TTaxi]

Dawn detergent, Ajax or Comet, & waterless hand cleaner work Ok as well.

[katkt]

Wet the area good with minerals spirits, and keep it wet(towels or rags) so it will penetrate instead of drying out. After an hour or so, use the soap( I like hot water) recommended above^^. It should lift the oil to the surface as the water gets under the spirits, and soaks into the concrete.

[MIQ]

There's a product called Castrol Super Clean. Its available at automotive stores like Shucks NAPA etc.
It de-solubalizes the oil. spray it on, scrub in a little w/ nylon brush, then hose it off..