Do you change your oil based on the amount of time it has been in your car. or by the mileage? For instance, If your oil has been in your car for 7 months, but you have only driven 2200 miles do you wait till you get to 3500 miles, or change it due to the fact it's been there 7 months?

 

7 months is nothing.
But if it's been sitting a few years, like 4 or 5, then I'll change it.

I change my oil every 5000 miles in my daily drivers with modern engines.
My 78 Pro-Touring Z28 has an LS1 so its' in this category.

But on the Olds I just check the oil level and color every Spring.
It might take me 2 seasons to hit 3000 miles to get an oil change.

I have 2 classics in restored condition and a Hayabusa + Harley.
I have to spread the usage in the 6-7 months I get here in Chicago

 

Once a year for most of them, as none get over 3000 miles in a year.
The 86 only gets about 200 miles a year and stays in the garage, so it might get a change every 2 years.
Speaking of which I have an oil change party coming up soon.........

 

I change the oil like I change my underwear. Once every ten years, even if it doesn't need it.

 

Jaunty ... does checking color help you know when a change is needed ?

 

You're talking about OIL, right???

 

 

On the 442 I change the oil every Spring. There is condensation with weather changes inside the engine and that gets into the oil as the car doesn't get driven all that much...not like a regular car where it will be burnt off the next day, so I just change mine. On the Intrigue and Aurora, I change the oil when they tell me too.

 

Once a year on the 57. Every 3k of the Cad STS. Old school thinking I know but oil is cheep compared to the the engine.

 

Every year in the Cutlass, whenever they tell me for the Intrigue.

 

On a more serious note, this is what I've always thought is the reason that you are always told in owners' manuals and the like to change the oil after both a certain number of miles OR a certain amount of time, whichever comes first.

Moisture can condense inside the engine, and that gets into the oil. For a regularly-driven car, the water gets boiled out and is gone. But if the car is not driven much, the water is not boiled out at as fast a rate as it condenses in, and internal corrosion can occur as well as poorer lubrication.

At least, this is what I've always operated under, and it makes sense. I drive my old cars at the rate of maybe 1,000 miles per year. If I went strictly on the mileage method, even the every 3,000 miles method (as opposed to 5,000, which manufacturers recommend now), it would be three years between oil changes, and that seems too long.


The '73 Custom Cruiser I bought last January is an interesting case. The last time it had had an oil change before I bought it was in January 1997, exactly 13 years earlier. However, in that time, it had traveled only 1,457 miles, and it had traveled zero miles between March of 2005 and when I bought it. Going by the mileage method, I should have been able to drive it at least another 1,500 miles. When I pulled the dipstick out, the oil looked as clean and as clear as the day it was put in. But I still changed it. It didn't seem right driving around with 13 year old oil. I changed the filter, too, even though it was basically as clean as a new one. Oil is cheap, filters are cheap, and changing the oil is pretty easy, so you have to do it.

 

I change it by oil pressure and fuel stench.
When the pressure drops between 35 and 40 P.S.I. when hot, I know the Oil is getting pretty washed. It's synthetic, so it would probably last me for years if I didn't beat the hell out of it all the time racing it.

 

The sad thing is, that old oil probably had better additives than the brand new stuff.

 

I change mine once a year sometime between Thanksgiving & Christmas when it will more or less go away for the winter. I'll still drive it a couple times in the winter on a warmer day w/ clean roads just to recirculate all the fluids & enjoy the car, maybe once each month for 10-20 miles. IMO it recoats everything in engine & driveline, gets hot enough, long enough to burn off any condensation.