[geegee]

You don't need an accurate measurement as there is an operating range for the oil level that proves satisfactory. If you check the oil with cold engine, all oil should have drained down and so the oil should read as high as it will ever read without adding more oil. This oil level should always be maintained at the full mark even if you have to add small amounts to get it there. I usually have a quart bottle handy in the garage to keep the oil level serviced.

There's no need to check your oil at every gas stop. If the engine is in good condition then this is a waste of time and risks contamination of the oil. If the engine is new and broken in, check it every 2000 miles else check it every 1000 miles. In newer engines the oil should make 2000 miles easily before the level drops to the add mark. In older engines or loosely built engines check it at 1000 miles. If you're not comfortable with this, check it more frequently but check it in the morning before you use the car rather than wait until you arrive at the gas pump. Changing oil at 4000 miles is a good practice for long engine life. You can change it earlier but you're wasting money for all modern SAE oils used in engines in good condition will wear for 8000 miles before starting to break down. Always change your oil not greater than 8000 mile intervals.

 

[GypsyR]

The best time to check the oil is first thing in the morning. You're Dad's right, there will be oil around in the engine instead of in the pan when it's hot. Sitting all night gives the oil plenty of time to drip down into the pan so it shows on the dipstick.
When I add a car to the collection, I do a normal oil change and pay particular attention to the dipstick reading. Then I go drive it and recheck the oil after the car is well warmed up, like you would at a gas stop. When the engine is hot you'll usually see a lower reading. From then on I know where the oil level should be, hot or cold.
BTW, my motorcyle is the opposite. It appears to have more oil in it when it's hot. Go figure. The oil checking technique applies, just in reverse.

 

[motorhead]

Either way is fine. The advantage of doing it first thing in the morning is you don't need to wipe the stick and you probably have a case of oil sitting near by. The advantage of doing it when you fill your tank is that you have a few minutes to kill anyhow. The oil is hot enough to settle to the pan quickly so there may be 1/8th of a quart of oil sticking to every part inside of your engine. And at a good gas station they have towles conveniently located so you can wipe the dipstick to get a good reading.

The most important thing is to check your oil before you blow an engine from lack of oil. On my newer cars i hardly ever check the oil Pretty much the only time i check it is when i over extend an oil change and i'm feeling guilty.

 

[L20068]

OK, thanks guys...

My engine only has about 11,000 miles on it and with all the money I've invested in it, it NEEDS to stay in tip-top shape. I use ONLY Mobil 1 10W-30 full synthetic oil every 2,500-3,500 miles (depending on driving conditions) complete with a Mobil 1 filter as well.

I understand how modern oils can be sustained for longer periods of time, but I just don't feel comfortable waiting so long. My mom and dad both subscribe to this notion, and it does pay off - My mom's 1990 Oldsmobile Delta 88 with the Series II 3.8 liter has over 390,000 miles - ORIGINAL engine and ORIGINAL transmission - And it still runs exactly like it did when we bought it. Other people with the same exact car have not been so lucky.

Every 3,000 miles, my pony gets a new fuel filter, air filter cleaning (K&N), carburetor cleaning, transmission service and radiator service. It may seem expensive, but I drive the car HARD and I expect it to last for a long time. My dad always says that there is no such thing as too much maintenance.

 

[Midlife]

I do a check of all the fluids of all the cars once a week. Every month, I check air pressure in the tires. That's more than sufficient.