My 2004 TL auto with 110,000 miles on it has only taken 4 qts of oil, it has always taken the 4.5 qts that the manual says until the last two oil changes. I switched to Mobil 1 Extended Performance 3 oil changes ago and used Mobil 1 synthetic since the car was new. I send to oil to Blackstone labs for analysis and they have all come back good. I added some Sea Foam to this change to see if it does anything. Any thoughts???

 

The Seafoam will loosen up everything in the crank case and allow you to drain more oil. Perhaps that will get you back to the 4.5 quarts.

 

Interesting.. keep us posted.

 

Maybe your burning 1/2 a quart between oil changes?

 

What size oil filter are you using? That could be the problem.

How are you changing your oil? Are you changing it when the car is super hot? Because you should be. Otherwise, not all of the oil will drain out.

 

drive 30 minutes solid on the freeway with 1/3 can of seafoam in the oil, then immedialty change while warm so all the sludge drains out

If you only took 4 qts last time - it wasnt fully drained~~

 

I'm nearing 80K miles, and the amount of oil I use, and refill with, is the same as the day I bought it. Nothing has ever been added between changes, and the refill amounts have always been spot on.
I've owned Acuras since 1998, with total mileage in excess of 300K, and never experienced anything other than what I have stated.
I do not warm the oil before draining, unless it is during the winter months.
That's just me and my 2 cents worth.

 

are u taking off the oil fill cap before u drain?