Synthetic or Dino?

Gem99ultra · Jul 8, 2014

I have an 8 year old 26 gallon Husky Pro air compressor that gets light duty, but had never had an oil change. I'd noticed that it no longer pressured up above 110 psi and also the oil was black, although at the full level. So, I decided to beak down and change the oil hoping to give it a little longer life.

No longer having the User's Manual for the compressor, I contacted Home Depot, the seller, for info on which oil to use and exactly how much. That info was not available on the Husky web site, nor at Home Depot. Their uninformed 'sales associates' didn't have a clue as to anything about air compressors except how to ring up a sale on their cash register :-( So, I tapped HD's web site Customer Assistance and asked them. They promptly came back with the info that my unit was discontinued and the info was no longer available.

Not being satisfied with that answer, I assured them that Husky DID have that info, and to call them and get it for me! Which they did - in about a week. They came back with this info:

Replace the oil with 8 oz. of 30W Non-Detergent oil, run for a minute, then top off to the Full level.
or
Replace the oil with the same amount of oil but instead using 10W-30 Mobil 1 Synthetic.

After dumping the old thick black oil I dumped a cup of diesel through it to wash out any filings or lingering sludge, then followed that up with a cup of 30W non-detergent oil... dumped that, then filled with fresh Non-Detergent oil (since I didn't have any 10W-30 Mobil 1 around), and topped it to the Full mark.

Thankfully, the compressor did run fine and the oil looked great. Pressure came up to about 115 psi and pump sounded good. But - I got to thinking, why would they suggest Mobil 1? So, I picked up a quart and changed the oil again - this time with the 10W-30 Mobil 1.

Wow! What a difference!!! The pump ran quieter AND the pressure went up to 145 psi.

My question is - do you think just changing the oil for clean oil made the difference, or is Mobil 1 that much better? Or perhaps something else happened to allow the pressure to increase?

Texasmark · Jul 8, 2014

My guess from personal experiences is that:

1. It is slicker, proven it more than once even for same grade premium dino oil. On your compressor, the smaller molecules probably helped to seal the interface better in addition to reducing the viscosity the motor had to turn against.
2. It stays thin when cold unlike your dino 30w. I run 0w-30 Mobil 1 in my truck. Ever see a dino rated 0w?
3. It doesn't breakdown at high temps like dino. I can run my air cooled lawn mowers for 2 full seasons sometimes between changes. With dino I used to have to change several times per season.

Funny, I think I remember this correctly, it has been in use in aircraft engines way back in the '40's

Was reading the other day about Amsoil history on their site and seems the guy that founded the company was a Korean jet jock (F-86) and noticed that they used syn in his jet. He got the idea to produce it for consumer use.

So it isn't something that the magician pulled out of his hat lately.

Mark

Copperhead · Jul 8, 2014

Yeah, synthetic has been around for a long, long time. The Germans in WW II were the first to really play in the synthetic sand box in a big way, though technically, lube products made from whale oil in the 1800's are still considered to be synthetics, though I sure would't want to put it in my engine! Motul was the first company to produce synthetic engine oils for the consumer marketplace, in the 60's. Either way, synthetics definitely have a their place in the scheme of things. Depends on the application if they are a worthy and cost effective choice. Each person has to decide for themselves. I use full synthetics in some applications and synthetic blends (synthetic and conventional blend) in others.

Gary Fowler · Jul 8, 2014

My first experience with full syn oil was in my 4 stroke 70HP boat engine. It got a full 500 rpm more throttle response with the syn oil in it.

Gem99ultra · Jul 8, 2014

Geez! I had NO IDEA that Mobil 1 was THAT good. From what I'm seeing, Mobil 1 is certainly worth the difference in price.

I was used to having gotten stuck with all of the 'snake oil' stuff out there. Some work, most don't.

murphy1244 · Jul 8, 2014

Do not use car oil in a compressor. I use Mobil RARUS 427 .

Gem99ultra · Jul 8, 2014

murphy1244 said:
Do not use car oil in a compressor. I use Mobil RARUS 427 .

Murphy1244, I sure did not know that. After reading up on air compressor oil, I do understand why not use automotive motor oil. So - I've ordered some Mobil RARUS 427 from Zoro and will change the oil (again). That compressor should last me for a lot of years with all of the oil changes that it's gotten this year

Seriously - thanks for the oil info.

Copperhead · Jul 9, 2014

Should sure be nice and clean inside!

Gem99ultra · Jul 9, 2014

Zoro had my Mobil RARUS 427 oil delivered today via UPS; free shipping! Unreal service; I just ordered it Monday. So, I swapped out the Mobil 1 10W - 30 for the Mobil RARUS 427. Compressor runs smooth and puts out 150 psi. I'll be changing the oil in the Husky Pro more often than once every 8 years!

Good info Murphy1244 - Thanks!

kenmac · Jul 9, 2014

Gem99ultra said:
Zoro had my Mobil RARUS 427 oil delivered today via UPS; free shipping! Unreal service; I just ordered it Monday. So, I swapped out the Mobil 1 10W - 30 for the Mobil RARUS 427. Compressor runs smooth and puts out 150 psi. I'll be changing the oil in the Husky Pro more often than once every 8 years!

Good info Murphy1244 - Thanks!

Murph gave you good advise. Years ago, I used Rarus oil in my compressors. Good oil. I now use Amsoil compressor oil