Oil change or no?

[pb4uski]

So if I have oil that sits on a shelf in a garage or a shelf in an auto parts store for a year then I should throw it out because it is no good to use?

That doesn't make any sense at all.

If that is so my Honda outboard that I just did an oil change on with some oil from last year is going to be really unhappy.

 

[Ferd]

Every vehicle manufacture recommends an oil change at least once a year. Oil in your crankcase is not the same as oil in a bottle. Oil in your crankcase will pick up water even if you don't drive unless you park the vehicle in a temperature and humidity controlled location.

 

[pb4uski]

Fair point. Given that, perhaps I should not have changed it.

How does it pick up water sealed in an engine but not if sealed in a bottle?

 

[RobbieB]

The crankcase is not sealed.

 

[pb4uski]

If it isn't sealed then why doesn't oil leak out?

I know it isn't as well sealed as a bottle, but it is designed so outside fluids can't get in and oil can't get out. How much condensation can there be if it is sitting in a garage that is -20F to +40F all winter?

 

[RobbieB]

It's not the condensation that's the problem, it's the oxidation. The water will all boil out on your next long drive. But that oil is exposed to oxygen in the crankcase and degrades over time.

 

[Sunset]

I change oil once per year, or every 5K miles, whatever comes close. I't been good enough all my life (except it used to be 3K instead of 5K miles a long time ago).

I don't have one of these fancy, oil GMC diagnostic reports (is this in the vehicle, or you take it to the dealer for an oil report ? ).

 

[53anddone]

Oil

I change oil once per year, or every 5K miles, whatever comes close. I't been good enough all my life (except it used to be 3K instead of 5K miles a long time ago).

I don't have one of these fancy, oil GMC diagnostic reports (is this in the vehicle, or you take it to the dealer for an oil report ? ).

I was like you until I bought a new car in 2017 (and another in 2018). Both have oil diagnostics and I am getting 8000 - 10000 miles in between changes.

 

[ERD50]

If it isn't sealed then why doesn't oil leak out?

I know it isn't as well sealed as a bottle, but it is designed so outside fluids can't get in and oil can't get out. How much condensation can there be if it is sitting in a garage that is -20F to +40F all winter?

It's not the condensation that's the problem, it's the oxidation. The water will all boil out on your next long drive. But that oil is exposed to oxygen in the crankcase and degrades over time.

What RobbieB said, plus, if you have driven it at all, you've had combustion blow-by get into the oil. So it sure is not the same as a sealed bottle on the shelf.

I'm impressed that it includes time, I'm not sure about my 2017 GM, but our 2011 Honda manual said to change oil once a year, regardless of the oil minder (which often still showed a good % left, as we drive low miles).

I'll add that for all those years, we were told how bad short drives are on a car, and how we need to change the oil more frequently. But most of our trips are short, like 5 miles, only about 3 for DW to work. I know the oil minders factor that in, but we still usually have % remaining after one year.

Sunset:

I don't have one of these fancy, oil GMC diagnostic reports (is this in the vehicle, or you take it to the dealer for an oil report ? ).

The oil minders use an algorithm, the subtract points for each start, run time, speed, load, monitor the temperature and a bunch of other things, with different point values for each ( a very cold start counts more than a hot start).

-ERD50

 

[pb4uski]

... I don't have one of these fancy, oil GMC diagnostic reports (is this in the vehicle, or you take it to the dealer for an oil report ? ).

It is in the vehicle... one of many choices from the dashboard. GMC also emails me a diagnostic report monthly (if the vehivle has been driven). I can also look at diagnostic reports, vehicle repair and maintenance history, etc. online.

 

[yakers]

I was on the opposite side of the spectrum when we had our turbo Miata. We only drove it 200 or so miles per year. I would wash the car and change the oil almost every time it was driven. I did it due to the age of the filter and how hard it was driven (bouncing off the rev limiter or close to it on almost every shift). My other vehicles get driven regularly and I change the Mobil 1 full synthetic about every 5K miles as cheap insurance.

I don't mind changing the oil and actually look forward to it since it gives me something to do and makes me feel like I am saving money on car repairs[/COLOR].

Changing the Miata oil filter is a PITA, always paid to have it done, changed oil myself on other cars (Jeep Cherokee, Jeep Liberty ...)

 

[yakers]

Every vehicle manufacture recommends an oil change at least once a year. Oil in your crankcase is not the same as oil in a bottle. Oil in your crankcase will pick up water even if you don't drive unless you park the vehicle in a temperature and humidity controlled location.

Well, DWs 2015 Ford Fusion Energi (Plug In Hybrid) specificly says up to two years. The engine works intermitententy, of our first 10K miles 7K were electric. Sure enough got the change oil light at 2 years. Very complex system, the engine will run periodically even if fully charged, it keeps the engine periodically warmed and checked out and recharges the 12V support battery. System is so complex they might as well weld the hood shut, nothing for me to do there.

 

[Music Lover]

The oil minders use an algorithm, the subtract points for each start, run time, speed, load, monitor the temperature and a bunch of other things, with different point values for each ( a very cold start counts more than a hot start).

-ERD50

And they're designed by people that know what they're doing. I just follow the oil minder on my car and apply my guesswork elsewhere

 

[bushpilot]

I start thinking about changing my oil at about 5000 miles, and usually get it done around 7000, and use whatever oil is on sale. Been doing this for a couple of decades now (I used to change at 3000 miles, religiously) and it works fine for me.