Change oil at 5,000 mi. or 4 months?



I have a 2003 Sable w/28,000 mi. No long trips, mostly around town, or trips under 100 mi. Is it better to wait for a mileage to be reached or a time interval before changing oil?


You’re supposed to change it when whichever occurs first. My shop puts a sticker on my windshield that says something like “next service due at 180,000 OR 03/2008”. Even if I haven’t reached 3,000 miles (which isn’t going to happen, my car gets driven ALOT) it still needs fresh oil to keep the life of the engine especially with seasonal changes. Then again, my car is 20 years old not 4 years old but you get the idea. Good luck.


Well it looks like you are reading the owner’s manual. Very good. Read a little closer and you will see it says “which ever comes first.”

So stick with which ever comes first.


5,000 miles or 4 months? Who told you that?

Read the owner’s manual. The 5,000 miles might be correct (MIGHT), the 4 months is totally BOGUS.

My guess is more like 7,500 miles or once a year, whichever comes first.


Thanks for your confirmation of what I had suspected. The manual and the dealership always push for 3,000 mi. or 3 months. A salesman at a dealership in Florida told me privately I didn’t need to go that often, but I’ve not had the nerve to challenge but I do delay. Then I get mail from this dealership saying “your 30,000 mi. checkup is due. Where are you?” Anyway, thanks.


You might try this…LOOK at the color of the oil on the dip-stick! When it goes from amber to brown, it’s time for a change. With my vehicles, that usually occurs around 3500 miles. During short-trip winter driving, it can occur as soon as 2500 miles. On a long summer road trip, it may still look good at 5000 miles.

When Toyota owners followed the 7500 mile recommendation, their engines turned into sludge buckets and Toyota had to replace many of them.

Lets not forget what is happening here. Piston rings do NOT seal perfectly. There is ALWAYS some blow-by of combustion gases. These contaminants slowly accumulate in the oil and become part of the oil. The only way to remove them is to change the oil.

I’ll let someone else explain the PCV system to you. This system purges 90% of the contaminants from the crankcase. Otherwise, you would have to change to oil every 1500 miles, like in the old days…

Some synthetic lubricants claim they can capture and hold in suspension 10,000 miles worth of combustion blow-by contamination and still protect the engine. Good Luck…