Oil in a bottle doesn't have a shelf life, but oil in an engine does. Due to gravity, when the engine is "off", the fuel in the fuel/air mixture in each cylinder will eventually find it's way past the piston rings and down into the crankcase, thereby diluting the engine oil and reducing it's viscocity which will cause unwanted engine wear.

 

This is going to date me, but I earned it. I have always done all my own work, from changing king pins to tranny synchcronisers, rear axle bearings and most everything else in-between. Computer driven cars have cut my ability by about 50%, and being 76 years old another 25-30%. Plugs, points, hot coils, Hurst Shifters, Carter AFBs rejetting, Mallory Distributors, etc, etc, aren't the fun they used to be. I therefore now limit most of my mechanical abilities to Driving, not aiming, and leaving the dirty work to others. Having said that, I had my engine oil (mobile 1) and filter (mercedes) replaced at the Boerne, TX Mercedes dealer on 7 May '08. The oil was $5.89 per qt, the filter $29, (cheaper than the Chrysler dealer, and full "A" schedule service, Labor about $30.00 + $3.00 shop fee.
I was met at the service lane by a classy articulate young lady who asked what I needed, SA, and opened the door and took me to a Service Advisor. We discussed the service etc, I left the car and went to San Antonio for lunch. Came back, the same young lady met me and said she would get the Serv Adv and told me the car was ready. I paid my bill, discussed the service with the advisor and he informed me my brake pucks (pads to kids) were worn about 1/3rd, gave me the service sheet with the tread measurements, and mentioned I had a small oil leak at the sensor which should be repaired under waranty. I had a complimentary iced soft drink and my wife had a bottle of Mecerdes-Benz Spring water that the young lady wiped the water and condensation off with a snow white towel. The "A" charge was $115.00 plus I picked up a Mercedes Cabin Air Filter for $46.00 that I can install myself. The FSS was reset as well as the clock. I will definately go back!!!! I also just received a JABSO Model 17860 3 1/2 gallon flat tank engine oil change system that I will try out first on my Intrepid, 2005 Neon SXT/SRT4 Clone and '95 "T" Bird LX 4.6L V-8. Shopped the "net" and the price went from $199.00, down to $134.00 and I bought mine new for $94.00 plus $9.99 flat rate FHL shipping with no tax. 12V/24V DC with integral power switch. I hate oil drips on the driveway and garage floor, so figure the least I can do myself is change the filter. A good mechanic these days is hard to find, so if I want something screwed up, I'll do it myself.

FTroopChief (John P)
2005 White Olebasta Coupe, 5 spg Triptonic
2005 Neon sxt/srt4 clone, 8,900 miles,
1998 Dodge Intrepid ES, loaded, 3.2 V-6, 30+mpg on the road @ 70mph.
1995, T Bird LX 4 spd auto OD, 4.6 V-*, 55,000 miles

 

They don't get any better than Texas ladies!

 

Changing the oil is very dependent on your style of driving. Lots of stop and go or lots of short trips (under 15 - 20 miles) will require you to change it more frequently. Long periods of driving will stretch your oil life out longer. Oil these days, especially our synthentic products, such as our beloved mobil 1 are made very good and can last longer than oil that was produced even 5 years ago. If your car is well broken in, and you use synthentic oil, and arnt making alot of short trips, you can easily drive 10k miles before changes. it is possible to change your oil to frequently.
i would absolutly change it as soon as you can after a new one or "left over" has been sitting a while.
Also Wix filters (with the fiber lining, not the paper) are about the best, if you can find them, but its one's own personell liking.

 

You Be so Diddly-d-darn right.
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FTroopChief, Heart of the Hills, TX