January 15, 2026, 07:11 PM
RPROGASF&L SP-3 Oxygenated Fuel Question
When F&L discontinued their SP-4 (non-oxygenated) I was forced switch to their SP-3, which
is oxygenated. The problem is they don't list the percentage of oxygenation so increasing the jetting and air bleed sizes becomes a lengthy trial and error process. Now, with the colder weather, this may become critical.
We believe the fuel is equivalent to Renegade K16 (5% oxygenation) or possible Renegade K13 (3%). Renegade recommends increasing the jetting/air bleed sizes
and volume for either fuel. The question is for those folks who are running K16 or K13 how many jet size increases did you find worked the best. I just need a ballpark number.
ps: Renegade Fuel isn't available here and VP is priced out of my acceptable range, F&L is the only fuel available.
Bob
January 16, 2026, 10:21 AM
B KINGquote:
Originally posted by RPROGAS:
When F&L discontinued their SP-4 (non-oxygenated) I was forced switch to their SP-3, which is oxygenated. The problem is they don't list the percentage of oxygenation so increasing the jetting and air bleed sizes becomes a lengthy trial and error process. Now, with the colder weather, this may become critical.
We believe the fuel is equivalent to Renegade K16 (5% oxygenation) or possible Renegade K13 (3%). Renegade recommends increasing the jetting/air bleed sizes and volume for either fuel. The question is for those folks who are running K16 or K13 how many jet size increases did you find worked the best. I just need a ballpark number.
ps: Renegade Fuel isn't available here and VP is priced out of my acceptable range, F&L is the only fuel available.
Bob
Bob,
I used to race a 1988 Mustang many years ago & the car owner used F & L racing fuel in it. The car was deadly & I won a bunch of races/$$$$ with the car. I don't know how much the fuel played a factor in the wins but the owner nor I was complaining.
I don't know what fuel we were using. Anyway, I looked at their oxygenated fuels & the highest I saw was 5%. I saw the SP-3 was listed just how you stated. I would jet up 2 sizes on all 4 corners & look at the plugs.
I would give F & L a call, they should be able to give more information on that fuel.
My fuel is oxygenated 3.7% by weight, according to Sunoco.
2BKING
January 16, 2026, 10:58 AM
TD3550SP-3 as per their site shows 5%. 2-4 is a starting point for any O2 fuel The q16 on average is this.
Color Yellow
MON 116
RON >120
(R+M)/2 >118
Specific Gravity 0.7155
Leaded / Unleaded Leaded
RVP 7.25 psi
Oxygenated 9.38%
Additional Info
I just jet as needed. Sometimes i would just cut the plug and examine the fire ring.
January 16, 2026, 01:56 PM
B KINGquote:
Originally posted by TD3550:
SP-3 as per their site shows 5%. 2-4 is a starting point for any O2 fuel The q16 on average is this.
Color Yellow
MON 116
RON >120
(R+M)/2 >118
Specific Gravity 0.7155
Leaded / Unleaded Leaded
RVP 7.25 psi
Oxygenated 9.38%
Additional Info
I just jet as needed. Sometimes i would just cut the plug and examine the fire ring.
Do you have a link to the above info?
This is what I found & it's conflicting.
https://racefuel.com/motorspor...ve/drag-racing-fuel/2BKING
January 16, 2026, 08:04 PM
RPROGASI contacted APD and they researched the F&L SP-3 oxygenated fuel. Their conclusion was that it's 3%. They recommended increasing both primary and secondary jets by 2-3 numbers, but leave the air bleeds alone. These figures are for the ADP Max Flow 1250.
I'll begin there and read the plugs for further changes if necessary, not a problem, I'm an old school plug reader.
Thanks for all the replies, I appreciate the help.
Bob