I've had some tight lug nuts recently that required a 1" impact wrench to loosen. After goofing around with my own compressors for a while I finally concluded that no 110 volt compressor would have the volume necessary to operate the wrench. The bigger the tank the more air you have to operate an impact wrench. A 5 gallon Harbor Freight pancake has been adequate for most of my other needs. I like it's portability to I can blow out my sprinkler systems.
I just picked up a used Campbell Hausfeld 30 gallon 135psi like new on Craigslist for $200. I also have an old belt driven oiled Craftsman that will still be running when I am long gone.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13