Anytime you clean with chemicals be sure to wear protective gloves and work in well ventilated areas for your safety. When you see that this is quite a job ahead of you never let yourself worry too much as there is always professional carpet cleaning company that can assist you with this and they will be happy to remove the oil from your driveways too.
How hot does a standard carpet cleaner go? What is the average BTU's in a carpet cleaner?
My brother has been cleaning carpets for 18 years. I think with the heat exchangers they reach about 150 degree's.
You must realize that oil breaks down at 250 degrees, synthetic is 300 degrees. So the standard carpet cleaner could not come close in hitting these temps at 6 GPM- 9 GPM. ( Gallons Per Minute)
On the same token, a 6 gpm pressure washer, one would be nuts to try to clean a carpet inside someones house because of the volume of water.
Below we are using a 3 ft radius 14 HP Honda that rotates the arms to a speed of over 3,000 RPM's. About 1200 rpm faster then self propelled. Except this one spins the arms backwards, thus cutting into the concrete, instead of the standard method of pushing off from the concrete. We find we actually get more downward pressure this way instead of loosing pressure that is used to spin the arms..
Detergent is just as important as heat and pressure. You then need to capture the waste water, filter out the heavy metals, and about 120 other items found in this soup of waste, then after meeting discharge requirements from your local POTW, then and only then are you able to discharge into the POTW system.
To date, there is not a carpet cleaning system that can possibly clean and oil stain as well as a pressure washer set up with a 1.1 million BTU Boiler on it.