Originally Posted by Mandingo

You probably know this, but I'm just throwing it out there for anyone else who might not.

If you are parked even slightly uphill, your dipstick will read lower than the true level. Conversely, parking facing slightly downhill will result in a higher than true reading.

So measuring oil level on the flat dealership lot, then on your driveway/garage will most likely give the wrong impression. For example: my garage floor at home is slightly angled for drainage but you would never be able to tell just looking at it. It affects the dipstick substantially.

This hadn't occurred to one of my family members. They thought they were burning oil when they really had only burned about 1/4 quart in 4000 miles.