Need help using a power washer

I am getting ready to borrow a friend's power washer to clean up all of the caked on grease and grime under the car. Since I got the oil leak stopped, I want to clean everything up. Anyone used a power washer for this, and if so, what cleaner/degreaser should I use.
Home Cheepo only has Citrus stuff, will this work or is there something better?
Thanks

Dukman, The best thing I have found for all around cleaning and grease/oil removal is Simple Green.
I own and operate a boat repair and service business and that stuff has so far outperformed anything else we have tried, including citrus cleaners.
Hope this helps, Mark

Hi chris ther are a number of spray cleaners you can use such as gunk and foaming engine cleaner . But woody made a good suggestion with the simple green . It is much cheaper and works really well , spraying down the engine while it is warm not hot speeds things along . A second application and a little brushing around the stubborn stuff will result in a nice looking job when done .

gman

Thanks guys, I completely forgot about Simple Green
If I want to spray it on with the washer applicator, do i use it full strength? (For areas where I can't reach/ differential, crossmember, etc)

Chris use it full strength ,and keep a hose handy to keep your paint work free of stains etc . Just in case you get some on the fenders etc.

gman

Thanks George

Haven't used a power washer on the car, but used Simple Green and a hose. Worked good!! Power washers are fun to use. I blew two holes through some plywood when I was cleaning up my barn (which still doesn't have a cement floor )