With the Biofuel refiner you can convert raw food and honey into fuel for your engines.
The quantity of raw food needed to create 1 biofuel depends on which type of food you use.
So i decided to test all raw foods and share the results.

Since the potato has the lowest efficiency all foods, all other foods will have their efficiency measured in potatoes.
It is important to know that a single unit of biofuel requires 20 potatoes worth of food (plus 1 unit of honey) and the refiner can store up to 40 potatoes worth of raw food.
Here is the list from best to worst.

Potato equivalent
********************
mama bear head = 40
puffer head = 30
shark head = 20
warthog head = 20
screecher head = 20
bear head = 20
sharkmeat = 15
red berries = 12.5
milk = 10
catfish = 10
salmon = 10
melon = 8
drumstick = 8
raw meat = 7
tilapia = 6.5
mackerel = 6.5
egg = 6
mango = 4
pineapple = 4
coconut = 4
pomfret = 4
herring = 4
raw beet = 1

2 raw foods are not compatible/bugged at the time of writing:
Mushrooms show prompt to add but nothing happens when pressing E.
Silver algae is not treated as compatible raw food (this one could be by design rather than
a bug).

Hope this info is of use.

(This guide was written by Marek15 and published with their permission!)