I'm not sure how you calculate burn rate, but I know the heat values. You can compare the heat values to each other, to make a direct comparison.
This is taken from the Railcraft wiki, which I'm pretty sure is accurate BEFORE the recent changes (fuel and ethanol were reduced by 75%):
- Nearly anything that burns in a Furnace may be used to feed a Solid Fuel Firebox.
- Bucket of Lava = 1000
- Charcoal = 1600
- Forestry Peat = 2000
- Coal = 3200
- Coal Coke = 6400
- Lava is not a valid liquid fuel, this is intentional.
- Creosote Oil = 4800
- Forestry Bio-Fuel = 32000
- BuildCraft Fuel = 96000