For Xmas I decided to get an air compressor for myself to save time removing lug nuts and the occasional use around the car.

To keep things on a budget I bought the following:

http://www.harborfreight.com/25-hors...sor-67847.html

At 90psi it outputs 4.7CFM.

To go with it I bought this 1/2 impact:

http://www.harborfreight.com/12-prof...nch-68424.html

On the site it says 4.4CFM at 90psi to run, however upon purchase the actual box says 6CFM at 90PSI.

I haven't broken in the compressor yet but when I hooked it all up for testing, set the pressure to 90PSI and the gun felt....really weak. Haven't actually tried it yet on the car but when I stopped by Harbor Freight and spoke to a sales guy, he said my compressor won't cut it.

So the question is, the gun runs optimally at 6CFM @ 90PSI. If I was to use it with my current compressor which only does 4.7CFM @ 90PSI, it'll work albeit weaker than rated/designed/optimal correct?

Any insights appreciated!

 

The impact gun will not have the power to get the really tight nuts and bolts loose (or tight) if the air compressor can't deliver the CFMs. The only thing you could do is get a air tank and run the impact gun off of the tank and the compressor re-fills the air tank. The bigger the tank, the longer you can use the impact at full power. Maybe a 10 gallon tank would be ok for your needs but I really don't know. You might have to get a 25 gallon tank. But then when you consider the cost of the under-rated compressor and an extra air tank, a higher capacity compressor might be cheaper and definitely take up less room.

 

Well I found out I had a defective compressor, returned it for a new one and everything works fine now. You are right about the CFM however it only matters when the compressor runs out of air, but mine is more than enough to remove lugs

 

That's way better than my setup...I've been using a Craftsman 1.5gallon? (the upright portable w/no wheels) that I use for work for the last 5 years w/a couple of Craftsman impacts and fortunately have never had issues even when taking off axle or subframe bolts.

Then again, I live around Memphis and have zero rust....I really want to get a decent upright compressor. It's no fun hearing a compressor running full tilt just to take a few lug nuts off lol!

Jeremy