Well, actually just motor oil.

My 2001 Neon SE is losing about a qt of oil every 500-600 miles. No slick on the parking spot, no visible drip, no burning oil smell, no white smoke, no radiator milkshake, no overheating. Just... 1 qt low every couple of fill-ups. The engine has ~160,000 miles on it, so it prolly just needs a ring job. Questions are as follows:

1: Is there a "best" grade of oil to be burning? Would be interested in answers from multiple points of view (economical, mechanical, environmental...)

1.5: Would a heavier grade oil lessen the problem?

2: Am I doing any really bad damage to the vehicle by not fixing this?

3: Since I'm essentially replacing all of the oil every couple hundred miles, do I need to be doing oil changes at all, or can I just change the filter every 5000 or so?

 

I have a 2000 with 177K. I need to put a 1/2 quart about every 500/700 miles. I also don't have leaks but you know it's going somewhere. I would guess that if the oil looks and feels good it might be ok but do ask a mechanic.