Hi there i won a toyota echo 2001 with 115K miles on it so far i have been changing the oil every 3K and no problems no need to add even a drop of oil between changes, but now i start using mobil 1 7500 i check the oil dipstick at 4K and the oil level was showing full , now i checked at 6K and the car was missing 1/3 of a quarter, wich i add taking into consideration that i havent change the oil since dec 2007 (6 months so far) is this normal or my engine is starting to burn oil Thanks in advance
It is normal to occasionally get different readings on the dipstick even though you have not lost any oil. Checking hot vs. cold, or on a slight slope, will do it. Check again next time and you may get the expected full reading.
Even if you are starting to use oil at the rate of 1/3 quart in 2000 miles, this is normal and acceptable. There is no cause for concern.
Less than a quart in 6000 miles is very acceptable. I would not start worrying until it gets to 1 quart in 1000 miles. Modern Japanese built engines do a very good job of staying sealed. However, there is nothing wrong with keeping an eye out for any spots of oil that the car leaves on the garage floor and having a mechanic check the engine for external leaks at its next service.
Take note that all engines use oil because some has to be left behind by the upper piston ring so it does not wear against the cylinder wall. Most loss is masked by the unburned hydrocarbons that make it past the rings and get mixed with the oil. Most of these get vaporized and burned by hard runs on the speedways but some of the heavier fractions still remain. This is the reason to change the oil at recommended mileage intervals.
Your oil consumption is nothing to worry about. Keep on driving.
You did not state the weight or thickness of the Mobil 1. This oil lubrictes extremely well, is very slippery and will likely show minor increased consumption when you switch from a regular mineral oil.
As mentioned, 1 quart in 6000 miles is extremely good for a 7 year old car; you have nothing to worry about!! Your engine is obviously in good shape, and Mobil 1 will make it last many more years.
Mobil 1 is not recommended for old cars with high engine wear, since it will mean high consumption of expensive oil.
Thanks a lot guys for letting me know this i was starting to get worry about making a rebuild on the engine , the tickness of the oil is 5w-20 mobil 7500 ( syntec blend)
Thanks again for taking the time to answer my questions you guys are great