S.O. Fuel Requirement

aceinspp · 2026-11-14T13:12:34-0600

Use what the manual says for your engine type. RJD

RevEngineer · 2026-11-14T17:42:57-0600

Cviator said:
Don't believe everything on youtube. Go by the manual. As a side note, I realize we don't tow, but my 2019 Ford Ranger had essentially the same note about using premium when towing or hot weather. The folks on that forum felt a real benefit with premium fuel when towing. Because of what Dodge states the only way to tell for sure is drag strip or dyno an R/T with regular and premium. I tend to use mid-grade, though the math states it would be cheaper to fill up at 1/2 a tank swapping premium and regular every other time.
One of these days I'll get around to doing a 0-60 run comparing fuel, but unless there's a dramatic difference there will be too many variables to be conclusive.

I’ve been running 93 in mine. I tried a tank of 87 a while back and the downgrade in performance was immediate and very noticeable, lost a few mpg too. The car ran ok, but just didn’t have the same pep and got kind of clunky going through the gears. The SO can run on 87 but it’s pulling ignition timing and limiting boost to do it.

aceinspp · 2026-11-14T21:00:01-0600

Well that is something I would have thought would not happen as long as the manual recommend 87. RJD

baabootoo · 2026-11-15T07:36:43-0600

RevEngineer said:
I’ve been running 93 in mine. I tried a tank of 87 a while back and the downgrade in performance was immediate and very noticeable, lost a few mpg too. The car ran ok, but just didn’t have the same pep and got kind of clunky going through the gears. The SO can run on 87 but it’s pulling ignition timing and limiting boost to do it.

I had this on my last one, and you could see when it pulled timing in the short-term mode and long-term mode. It was great for testing gas. It attached to the OBD2 port. Unfortunately, it doesn't work on the new one.

RevEngineer · 2026-11-15T10:01:29-0600

baabootoo said:
I had this on my last one, and you could see when it pulled timing in the short-term mode and long-term mode. It was great for testing gas. It attached to the OBD2 port. Unfortunately, it doesn't work on the new one.
View attachment 3187

I have a couple of Diablosport devices I would like to log with but they won’t recognize the car. Not yet anyway….

Cviator · 2026-11-15T16:52:06-0600

RevEngineer said:
I’ve been running 93 in mine. I tried a tank of 87 a while back and the downgrade in performance was immediate and very noticeable, lost a few mpg too. The car ran ok, but just didn’t have the same pep and got kind of clunky going through the gears. The SO can run on 87 but it’s pulling ignition timing and limiting boost to do it.

Yes, I think that is what the SO does, however I haven't seen any data or written description of the system.
I do think it is likely the engine control computer will continue to optimize the system for a higher octane than the car is specified for, at least up to a limit.