If oil expands or contracts when hot, and how much at what temperature could be debated for days. From the practical standpoint, I doubt if there is a cup full of difference either way. I don't have a problem checking my oil with a cold engine as long as it hasn't been started. If you start the engine and shut it off cold, it will take thousands of Seybolt seconds for the oil to drain back to the pan. Hot or cold what is important is to pull the stick and wipe it before dipping it again to take a reading. These modern oils will stay at the last highest reading for weeks. You can't just pull the stick and take a reading. A tip for you guys maintaining several cars and wasting time getting the oil level correct after an oil change. To save time when I had a service facility going full tilt years ago, I had my mechanics sprnd extra time and carefully determine the correct amount of oil they put in a car. Then with a set of number punches, they punched ,for example, 6.5 on the dipstick. When the car came back for future service, the mechanic just had to check the #s on the dipstick. Also you troups and troupettes with diesel engines with the filter up above will leave a quart of dirty oil in the car if you don't remove the filter cover before draining the oil.

Peter

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Auto Zentral Ltd.

When I change the oil in my diesel. I do open the drain plug first, then remove the oil filter cover. All this discussion about when and where the oil should be, and yet no one seems to mention the simple way of measuring oil. Check your oil at the same, everytime. Be it stone cold or warm and sitting for 10 min, just be consistent. This way you can determine if your engine is using oil. When I have added the prescribed 2 gal. of oil after an oil change, I start the engine to get the oil pressure up and then shut her off. I check to see where the oil level is after a few minutes and use that as a reference point. The oil may be "cold", but as long as I check the oil under the same conditions, ie "cold", then I can guage any oil usage.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

During May 2000 I bought a 1995 E420. When I did the oil and filter change for the first time, I put in exactly 8 1/2 quarts as the manual calls for. The oil level came up to midway between minimum and maximum. That is the same level it always was at whenever I checked it prior to the oil change.

Before that oil change I was concerned that the car had burned some oil since it wasn't at the max level. Based on this experience with the E420, I now think Mercedes intends for the middle point to be the proper oil level.

Bob

I think mid-level is right. Oil expands when it gets warm, let alone 8+ quarts.

Somewhere on this site I read where someone had continuously filled their engine with oil right up to the full mark and it always went down to about mid point on the dip stick. As I recall they at first thought it was some mysterious leak.

Haasman

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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

i'm with Bob on this. i will check my dipstick on the level
oil on my next oil change.

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joel

Prayers bring forth enlightenment.

I think you all answered my original question. With Bob's answer above and him having the same car I concur with him and My 95 E420 measures at the same mid level point. I didn't think a simple question like this would have generated the interest it did (2 pages) but that goes to show you should never feel bad or stupid to ask ANY question related to cars... we all have different experiences and sharing all that helps the rest of us... like you did here! Cheers

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Joe95E420