How long can Aeroshell 15-50 remain good on the shelf? Would you use some that was 10 years on the shelf?
All aviation oil now comes with a "sell by" date stamped on the case (but not the bottle). The FAA has recently been snooping around shops and lashing them if they have outdated oil on the shelf. However, the date is a very long way out -- like five years or more. Also, I've not heard of any consequences for individual owners who aren't keeping the cases to know what the "sell by" date is for the bottles in their hangars or baggage compartments. And, as Tom notes, there is no real evidence of which I know that "expired" oil is any less good than "unexpired" oil.
Perhaps the FAA owns stock in Shell, ExxonMobil, and Phillip Petroleum, because that's the only explanation I can think of for the FAA's position if it's only a "Nice way to sell oil." But I know a petrochemical engineer who used to do aviation products for a living, and I'll ask him for his opinion on that.Nice way to sell oil. After all, isn't the crude from which it is made some umpteen million years old.
Perhaps the FAA owns stock in Shell, ExxonMobil, and Phillip Petroleum, because that's the only explanation I can think of for the FAA's position if it's only a "Nice way to sell oil." But I know a petrochemical engineer who used to do aviation products for a living, and I'll ask him for his opinion on that.
"Several years" is consistent with the "sell by" dates I've been seeing, so maybe there is a good technical reason for it -- long-term stability under unknown conditions of temperature, etc. Yes, you may find some oil from 1935 is still fine if it was never exposed to extreme conditions, but you might also find oil from ten years ago which has deteriorated due to exposure to extreme conditions. So, do you know where your oil's been?Motor oil in a sealed container should be stable for several years. The
only reason I can see for dating it would be to determine whether an oil is
from a new formulation, since our aircraft oils don't have the SAE rating
circle like automotive oils. But even then, it's the date manufactured, not
expired, that matters.
Response from petrochemist:
"Several years" is consistent with the "sell by" dates I've been seeing, so maybe there is a good technical reason for it -- long-term stability under unknown conditions of temperature, etc. Yes, you may find some oil from 1935 is still fine if it was never exposed to extreme conditions, but you might also find oil from ten years ago which has deteriorated due to exposure to extreme conditions. So, do you know where your oil's been?
Response from petrochemist:
"Several years" is consistent with the "sell by" dates I've been seeing, so maybe there is a good technical reason for it -- long-term stability under unknown conditions of temperature, etc. Yes, you may find some oil from 1935 is still fine if it was never exposed to extreme conditions, but you might also find oil from ten years ago which has deteriorated due to exposure to extreme conditions. So, do you know where your oil's been?
I guess if you buy oil and it sits around for so many years the date on the box passes, you've made the error of buying and carrying excess inventory.I do, because the oil doesn't set around long.
Most likely an ISO/TS deal. I sell material that pretty much never goes bad, but the factory puts a 3 year shelf life on it for ISO/TS purposes. When asked, "why three years?", we were told, "We had to pick a number, so we picked three." One competitor happened to pick 5 years.
I've got customers that have used stuff that's 15 years old with no issues.
When oil decays does it turn back into a dinosaur?
I guess if you buy oil and it sits around for so many years the date on the box passes, you've made the error of buying and carrying excess inventory.
I read somewhere that the State of New Jersey requires all food products, including water, to carry an expiration date not longer than two years from date of manufacture.Have you noticed there's an expiration date on bottled water? What's with that?
Have you noticed there's an expiration date on bottled water? What's with that?
How long can Aeroshell 15-50 remain good on the shelf? Would you use some that was 10 years on the shelf?
A long time, and no, I wouldn't run it, but then I wouldn't run it if it was fresh either.
Have you noticed there's an expiration date on bottled water? What's with that?
So.... Why don't you like Aeroshell 15-50, and what do you prefer and why?
What do you consider extreme temperatures? What's the decomposition mechanism?Response from petrochemist:
"Several years" is consistent with the "sell by" dates I've been seeing, so maybe there is a good technical reason for it -- long-term stability under unknown conditions of temperature, etc. Yes, you may find some oil from 1935 is still fine if it was never exposed to extreme conditions, but you might also find oil from ten years ago which has deteriorated due to exposure to extreme conditions. So, do you know where your oil's been?
The synthetic base stock used is not fully compatible with Avgas use. I'm not a fan of synthetics anyway, so I use Phillips 20-50.
Just make sure you don't do this.
http://www.htownracing.com/forums/showthread.php?t=40915
It's old, but still awesome.
So.... Why don't you like Aeroshell 15-50, and what do you prefer and why?
FWIW, Lycoming requires the LW-16072 additive only in the O-320H, O-360E, LO-360E, TO-360E, LTO-360E, TIO-541 & TIGO-541.Because Aeroshell 15W50 has a additive package that contains a compound called Tricresyl Phosphate. (TCP) and other compounds to comply with Lycomings required AD to add the snake oil.
I would point out that to scavenge lead in your cylinders, the TCP must be added to your fuel, not your oil. If you want to do that, Alcor is the only supplier of TCP to be used as a fuel additive. IIRC, Aircraft Spruce has it.From http://www.avblend.com/faa/kas_thomas_lenckite.html I find:
TCP Concentrate (the fuel additive from Alcor), is a prominent exception. The evidence is irrefutable, at this point, that TCP - by adding lead scaveniging - significantly improves spark plug life in engines that use leaded gasoline. As it turns out, tricresyl phosphate is also a good anti-scuff agent and therefore has a legitimate role in oil fortification. (Shell's use of TCP in 15W-50 Multi grade, and Lycoming's use of it in LW16702 oil additive, are 100% justified).
Just make sure you don't do this.
http://www.htownracing.com/forums/showthread.php?t=40915
It's old, but still awesome.