Royal PurpleSYNTHETIC COMP OIL 1 Quart

A great product - Works as it should.

I have a really old compressor that's Frankensteined together, the only original part is the tank. Aftermarket Pump,electric motor, pulleys, pressure switch, differential switch, piping, the works. Anyways I always just ran a traditional ISO 100 Non synthetic oil in it. Recently it started to make a rattle noise upon compression at 40PSI for about 2 seconds. After switching to this oil it no longer makes the rattling noise and the head temp is around 10-15 degrees cooler after multiple run ups and the pump is also quieter. I couldn't be happier!

I bought this synthetic oil to use in my John Deere 3800 psi pressure washer and Central Pneumatic 21 gallon, 2.5 HP air compressor. I use my air compressor for occasional auto maintenance and trim work in my home and my pressure washer for routine house, deck, and car cleaning. Occasionally, my friends will stop by to use them but I am by no means a "professional" user. I have had both of these for about 10 years and change the pump oil every spring. I of course top off the oil as needed between changes. I have always used synthetic motor oil in the small engines but just conventional compressor oil. Normally, I just pick up a quart of some random compressor oil for about $8/quart and change it out with that. I was recently researching synthetic compressor oils and Royal Purple kept showing up as one of the top rated fully synthetic oils out there so I decided to give it a try. I ran my compressor and pressure washer for about 5-7 minutes and flushed the oil with the cheap stuff. I ran them again and checked the temperature with an IR thermometer then drained the oil and put in the Royal Purple. Although I don't have a decibel meter, both were noticeably quieter. After they both had cooled down for a few hours I ran them again and checked the temperature with the IR and they were about 10°F-15°F cooler. They normally run around 220°F but are now running about 205°F-210°F so that is a definite improvement. Although this stuff runs about $20/quart, it is definitely worth it because of the lower pump temps and quieter operation which I assume means that the lubrication is much better. I will definitely be buying Royal Purple again.

I've personally used several different oil addatives for a couple of years now just to keep my old 4Runner running smooth and efficient. Personally, Royal Purple is my go-to oil additive, though, one can't go wrong with Rislone Hyperlube Oil Supplement or even the high mileage version. From my experience with Rislone Hyperlube Oil supplement, it's a great product; but the only thing it's missing is the air flow technology as well as separating from water technology. And, I will say that STP Ceramic Oil Treatment does just as great ,too. It keeps the lifter and pistons from wearing out and making a protective coating inside the engine.

Decent price for a full synthetic compressor oil, but the 2 day shipping is ultimately why I went with it. Royal purple has a reputation for very high quality synthetic oils and I’m sure this is no different. There is an issue with this, if you’d call it that is This stuff is very thick in cold temps (despite its claimed -39f pour point). ISO 100 is 30wt. Above 50 degrees F it works great, my compressor kicks on and the pump is up to full rpm in a few seconds with no issues. Below 50, and the colder it gets it takes like 30 seconds for the pump to reach full speed. Belt is squealing the whole time it’s getting going because the oil is so thick and which makes it hard for the pump to turn so the belt slips. I even got some stick on crank case heaters for it to warm up ahead of time. It helps some if they’ve been on for hours before using it but still not great. Aside from the start up issues, the oil isn’t splashing and lubricating well when it’s really cold and thick as molasses.If your compressor is in a heated shop, or your live somewhere where it’s warm most of the year this is a good choice for oil. But if you’re in a colder climate and your compressor isn’t in a heated shop I would recommend something else. This same oil in 20wt, like a ISO46 would be a good choice. Or a multi viscosity oil like IRs all season or Quincy quin cip D (specifically D). Looking in my manual Quincy only recommends iso100/30wt above 60 degrees.

I have used Royal Purple motor oil, gear oil, and compressor oil for years I use it for my compressor that supplies air to my pcp airguns. The compressor oil separates the water from the oil fast and it’s lubricity is well known. This oil is hard to beat. I use it in my Yong Cheng High Pressure DIGITAL compressor to fill my pcp guns and supply tanks. DrDave. Utah, USA

Dropped the temps on my compressor by 30 deg measured with ir thermometer at the crankcase and outlet at head. Sounds happier too. Radiant heat dropped also. Two heavily used 80 gal ignersoll rand 2 stage piston 15 gpm units. Used ignersoll oil before this switch. Highly recommend and I am very happy.

Great stuff, made my compressor run quieter and cooler than the factory oil.