Recent content by magneticanomaly

50 yr, no, this is the only drum of Mobil Delvac 1300 Super I have ever bought and used. Exhaust, yes, polymers are used to improve viscosity index by unfolding with increased temperature. But whether these particular polymer molecules are prone to linking up to form longer chains, or more...

To Dutchy, could be 10 years. Is 10-year-old oil, apparently clear and of normal viscosity, on the edge of polymerization? Will sett;ling leave the supernatant ready to gel? I am trying to understand what has happened and why. I will buy new oil, But as long as I have no idea why "old" oil...

From a local fuel and oil distributor....not a guy in a trenchcoat in an alley.

Rust Belt Pete's answer is very interesting, but there is no DEF (urea) anywhere around here. I think sabotage is also unlikely. I asked about water because some posters proposed it, and certainly moisture/humidity could have gotten into the drum as it breathed with temp variation, but the...

I have given samples both of unused oil from the drum, and the gelled stuff, to the oil dealer, in hope of getting them or their source to get an analysis. Perhaps one or more of you would be so kind as to suggest suitable , maybe even reasonably-priced, analytical labs? I am not trying to diss...

I bought Mobil Delvac 1300 Super HD multigrade engine oil by the drum, to save money. Have a pump mounted on the drum, in a shed. Takes me several years to use it up. I change oil not very regularly, but after a few thousand miles or a year or so. Do not drive a lot. Run this oil in...