McCulloch Fuel Ratio's Gasoline                                       40-1  ratio                                     20-1 ratio                                                  Custom Lubricant                     SAE 40 2 Cycle oil ================================================================= 1/2 US Gal ............................1.6 oz or 48ml (cc)                     3.2 oz or 95 ml (cc) 1    US Gal ............................3.2 oz or 95ml ..........................6.4 oz or 190 ml 5    US Gal .............................16 oz or 475 ml ......................32.0 oz or 950 ml 1 Litre .....................................0.9 oz or 25ml .........................1.7 oz or 50 ml 5 litre ......................................4.3 oz or 125ml .......................8.5 oz or 250 ml 20 litre ..................................17.0 oz or 500ml ..................34.0 oz or 1000 ml 1 Imp Gal ...............................4.3 oz or 125ml ..........................8.6 oz or 250ml 2 Imp Gal ...............................8.6 oz or 250ml .........................17.1 oz or 500ml 5 Imp Gal .............................21.4 oz or 625ml .........................42.8 oz or 1250ml Mixing procedure                        40 parts gasoline to             20 parts gasoline to                                                         1 part lubricant                    1 part lubricant 1ml =1 cc

McCulloch also used a fuel ratio of 32-1 in their Hi-Performance chainsaws like the SP81, PM850.