For oil, I assume you mean the change in SG from its value at 60F or standard temperature. The GPSA Engineering data book has a generalized chart that I typically use. It's likely published also in a lot of other reference books. There won't be much change in SG from going from 60F to 100F, not more than 1% or 2% for an oil.
The GPSA curve shows the SG as a function of temperature and SG at 60F. What I've done is developed the formula for the slope of those lines (they are linear over a reasonable temperature range) and then set up my own equation to estimate the new SG given the temperature and the SG at 60F.
Thanks TD2K for the info.Interested in that formula, or the principles behind it.I'm new in the business and my reference data base is not where I need it yet.